Patent Publication Number: US-10328306-B2

Title: Information-presentation structure with impact-sensitive color change and overlying protection or/and surface color control

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is related to the following U.S. patent applications all filed the same date as this application and inventions of Ronald J. Meetin: U.S. patent application (“USPA”) Ser. No. 15/343,101, now U.S. Pat. No. 10,258,825 B2; U.S. patent application Ser. No. 15/343,113, now allowed; U.S. patent application Ser. No. 15/343,115, now allowed; U.S. patent application Ser. No. 15/343,121, now U.S. Pat. No. 9,789,381 B1; U.S. patent application Ser. No. 15/343,123, now U.S. Pat. No. 10,279,215 B2; U.S. patent application Ser. No. 15/343,125, now allowed; U.S. patent application Ser. No. 15/343,127, now allowed; U.S. patent application Ser. No. 15/343,130, now U.S. Pat. No. 10,258,826 B2; U.S. patent application Ser. No. 15/343,131, now U.S. Pat. No. 9,855,485 B1; U.S. patent application Ser. No. 15/343,132, now U.S. Pat. No. 10,258,827 B2; U.S. patent application Ser. No. 15/343,133, now U.S. Pat. No. 10,252,108 B2; U.S. patent application Ser. No. 15/343,134, now U.S. Pat. No. 9,764,216 B1; U.S. patent application Ser. No. 15/343,136, now U.S. Pat. No. 10,130,844 B2; U.S. patent application Ser. No. 15/343,137, now U.S. Pat. No. 10,112,101 B2; U.S. patent application Ser. No. 15/343,140, now U.S. Pat. No. 9,925,415 B1; U.S. patent application Ser. No. 15/343,143, now U.S. Pat. No. 10,004,948 B2; U.S. patent application Ser. No. 15/343,148, now U.S. Pat. No. 10,071,283 B2; U.S. patent application Ser. No. 15/343,149, now U.S. Pat. No. 10,010,751 B2; and U.S. patent application Ser. No. 15/343,153, now U.S. Pat. No. 9,744,429 B1. To the extent not repeated herein, the contents of these other applications are incorporated by reference herein. 
     FIELD OF USE 
     This invention relates to information presentation, especially for sports such as tennis. 
     BACKGROUND 
     Two sides, each consisting of at least one player, compete against each other in a typical sport played with an object, such as a ball, which moves above a playing surface and often impacts the surface. Exemplary sports include tennis and basketball. The playing surface, referred to as a court, consists of an inbounds (“IB”) playing area and an out-of-bounds (“OB”) playing area demarcated by boundary lines. When the object impacts the OB area, the side that caused the object to go out of bounds is typically penalized. In tennis, a point is awarded to the other side. In basketball, possession of the basketball is awarded to the other side. Decisions as to whether the object impacts the playing surface in or out of bounds are often difficult to make for impacts close to the boundary lines. 
     Additionally, the IB area typically contains internal lines that place certain requirements on the sport. For instance, a tennis court contains three internal lines which, together with the tennis net and a pair of the boundary lines, define four servicecourts into which a tennis ball must be appropriately served to avoid a penalty against the server. It is often difficult to determine whether a served tennis ball impacting the playing surface close to one of these lines is “in” or “out”. Each half of a basketball court usually has a three-point line. At least one shoe of a player shooting the basketball must contact the court behind the three-point line immediately prior to the shot with neither of the shooter&#39;s shoes touching the court on or inside the three-point line as the shot is taken for it to be eligible for three points. It is likewise difficult to determine whether this requirement is met when the shoes are close to the three-point line. 
     Returning to tennis,  FIG. 1  illustrates the layout of playing surface  20  of a standard tennis court with line width somewhat exaggerated. For singles, playing surface  20  consists of rectangular IB playing area  22  and OB playing area  24  edgewise surrounding IB playing area  22  and extending to court boundary  26 . Singles IB playing area  22  is defined inwardly by two opposite equal-width parallel straight baselines  28  and two opposite equal-width parallel straight singles sidelines  30  extending between baselines  28 . Tennis net  32  is situated above a straight net line, usually imaginary but potentially real, extending parallel to baselines  28  substantially midway between them and extending lengthwise between and beyond singles sidelines  30  for dividing singles IB area  22  into two singles half courts. 
     Singles IB area  22  contains (i) two opposite equal-width parallel straight servicelines  34  situated between baselines  28  and extending lengthwise between singles sidelines  30  at equal distances from the imaginary or real net line and (ii) straight centerline  36  extending lengthwise between servicelines  34  at equal distances from singles sidelines  30 . Lines  30 ,  34 , and  36  in combination with the imaginary/real net line, and thus effectively net  32 , define inwardly four equal-size rectangular services courts  38 . Lines  28 ,  30 , and  34  define two equal-size rectangular backcourts  40 . 
     Playing surface  20  for doubles consists of IB playing area  42  and OB playing area  44  edgewise surrounding IB playing area  42  and extending to court boundary  26 . Doubles IB playing area  42  is defined inwardly by baselines  28  and opposite equal-width straight doubles sidelines  46  located outside singles IB area  22 . The imaginary/real net line situated below net  32  extends lengthwise between and beyond doubles sidelines  46  for dividing doubles IB area  42  into two doubles half courts. Net  32  extends fully across IB area  42  and into OB area  44 . Rectangular doubles alleys  48  extend along doubles sidelines  46  outside singles sidelines  30 .  FIG. 2  is a less-labeled version of  FIG. 1  in which roughly elliptical items  50 , of somewhat exaggerated size, represent examples of areas where tennis balls, including just-served tennis balls, contact playing surface  20  and which are variously so close to the tennis lines that it may be difficult to make decisions, referred to as “line calls”, on whether the balls are “in” or “out”. 
     Players and tennis officials variously make line calls in tennis depending on the availability of officials. Numerous devices, including camera-based devices, have been investigated to assist in making line calls. One notable camera-based device is the Hawk-Eye system in which a group of video cameras in conjunction with a computer track moving tennis balls to provide simulations of their trajectories and predictions of their court contact areas. See Geiger, “How Tennis Can Save Soccer: Hawk-Eye Crossing Sports”,  Illumin,  25 Mar. 2013, 3 pp.  FIG. 3  illustrates an example of simulated trajectory  60  of tennis ball  62  tracked with Hawk-Eye on one stroke.  FIG. 4  depicts simulated contact area  64  of ball  62  near a sideline  30  on another stroke. As  FIG. 4  indicates, Hawk-Eye provides a visual notification specifying whether ball  62  is in or out. 
     The Hawk-Eye simulations are displayed on a screen at which players (and officials) look to see the line calls. This disrupts play. As a result, Hawk-Eye is used for only certain line calls. In particular, officials initially make all line calls with each side allocated a small number of opportunities to challenge official-made calls per set provided that a challenge opportunity is retained if an official-made call is reversed. The use of challenges is distracting to the players. Hawk-Eye&#39;s accuracy depends on the accuracy of the predictive data analysis for the simulations and on Hawk-Eye&#39;s alignment to the tennis lines, assumed to be perfectly straight even though they are not perfectly straight. Hawk-Eye appears to occasionally make erroneous calls as discussed, e.g., in “Hawk-Eye”, Wikipedia, en.wikipedia.org/wiki/Hawk-Eye, 18 Jul. 2013, 8 pp. While Hawk-Eye has gained high recognition among the camera-based devices, it is desirable to have a better device than Hawk-Eye or any other camera-based device for making line calls. 
     Line-calling systems utilizing tennis balls with special electrical or chemical treatments have been proposed as, e.g., disclosed in U.S. Pat. Nos. 4,109,911 and 7,632,197 B2. However, such systems are disadvantageous for various reasons. Erosion along the outside of a specially treated tennis ball as it contacts the tennis court and racquets may detrimentally affect the ball&#39;s ability to provide the information needed to appropriately communicate with the line-calling system. The electrical or chemical treatments may so affect the bounce characteristics that some tennis players are averse to using specially treated balls. Players and officials are generally unable to rapidly verify the accuracy of the calls. 
     The possibility of using piezochromic material in making line calls has been raised. A piezochromic material changes color upon applying suitable pressure and returns to the original color upon releasing the pressure. In Bradley, “Interview with William James Griffiths”,  Reactive Reports , June 2006, 3 pp., Griffiths proposes a thin device to be laid on a tennis court and to contain piezochromic material that changes color upon being impacted by a tennis ball. Griffiths mentions that (i) the piezochromic material would have to be shielded from ultraviolet radiation because piezochromic materials are ultraviolet sensitive and most tennis courts are outdoors and (ii) piezochromic materials generally undergo reverse color change too quickly for a person to check an impact location. Ferrara et al., “Intelligent design with chromogenic materials”,  J. Int&#39;l Colour Ass&#39;n , vol. 13, 2014, pp. 54-66, similarly proposes that electrochromic paint be applied at and near the lines of a tennis court for assistance in making line calls and that the same paint could be used for basketball, volleyball, and squash courts. 
     Tennis players are usually close to baselines  28  during much of a tennis match. The players&#39; shoes would likely cause color changes near baselines  28  in a tennis court using the piezochromic material of Griffith or Ferrara et al. Shoe-caused color changes would sometimes partially or fully overlap ball-caused color changes and thereby degrade the ability of using ball-caused color changes in making line calls. 
     Charlson et al., International Patent Publication WO 2011/123515, discloses a “piezochromic” device, perhaps better described as an electrowetting device, which changes color in response to a force. One embodiment is a sports tape for determining whether a tennis ball is in or out. Other devices using pressure/force sensing have been investigated for assistance in making line calls as disclosed in, e.g., U.S. Pat. Nos. 3,415,517, 3,982,759, 4,365,805, 4,855,711, and 4,859,986. Line-calling devices using other technologies have also been investigated as, e.g., described in “Electronic line judge”, Wikipedia, en.wikipedia.org/wiki/Electronic_line_judge_(tennis), 19 Jun. 2012, 3 pp. These other line-calling devices are impractical for one reason or another. It is desirable for tennis and other sports needing fast line calls to have a practical line-calling device or system which overcomes the disadvantages of prior art line-calling systems. 
     GENERAL DISCLOSURE OF THE INVENTION 
     The present invention furnishes an information-presentation structure in which suitable impact of an object on an exposed surface of an object-impact (“OI”) structure during an activity such as a sport causes the surface to temporarily change color largely at the impact area. Specifically, a variable-color (“VC”) region of the OI structure extends to the exposed surface at a surface zone and normally appears along it as a principal surface color. An impact-dependent (“ID”) segment of impact-sensitive color-change (“ISCC”) structure in the VC region responds to the object impacting the surface zone at an ID object-contact (“OC”) area, whose shape is capable of being arbitrary, by causing an ID portion of the VC region to temporarily appear along an ID print area of the zone as changed surface color materially different from the principal color if the impact meets threshold impact criteria. The print area closely matches the OC area in size, shape, and location. 
     In one aspect of the invention, a protective structure lies at least partially between the surface zone and the ISCC structure for protecting it from being damaged by matter impacting, situated on, and/or moving along the zone. The protective structure usually absorbs shock of matter impacting the zone. The protective structure also preferably blocks at least 80% of externally incident ultraviolet radiation. 
     In another aspect of the invention, a surface structure lies between the surface zone and an interface with the ISCC structure. The total light normally leaving the ISCC structure along the interface is of wavelength suitable for forming a principal internal color. When the ID portion temporarily appears as the changed surface color, the total light temporarily leaving an ID segment of the interface spanning the ID portion along the interface is of wavelength suitable for forming a changed internal color. One of the internal colors is a comparatively light color. The other is a comparatively dark color. The surface structure absorbs light leaving the ISCC structure along the interface such that the principal surface color is darker than the light color if the principal internal color is the light color and such that the changed surface color is darker than the light color if the changed internal color is the light color. This light/dark color arrangement advantageously enables the colors implementing the principal and changed surface colors to be significantly varied by changing the light absorption characteristics of the surface structure without changing the ISCC structure. The principal and changed surface colors can also be created in different shades by varying the reflection characteristics of the surface structure without changing the ISCC structure. 
     The ISCC structure preferably includes an impact-sensitive (“IS”) component and a color-change (“CC”) component. An ID segment of the IS component provides an impact effect if the impact meets the threshold impact criteria. An ID segment of the CC component responds to the impact effect by causing the ID portion to temporarily appear as the changed surface color. Use of separate IS and CC components provides many benefits. More materials are capable of separately performing the impact-sensing and color-changing operations than of jointly performing them. The ambit of colors for implementing the principal and changed surface colors is increased. The print area can be even better matched to the OC area. The ability to select and control the CC timing is improved. 
     Instead of having the ID portion change color directly in response to the impact if it meets the threshold impact criteria, the ID segment of the ISCC structure can provide a characteristics-identifying impact signal if the threshold impact criteria are met. The impact signal identifies an expected location for the print area and supplemental impact information for the impact. Responsive to the impact signal, a CC controller determines whether the supplemental impact information meets supplemental impact criteria and, if so, provides a CC initiation signal. The supplemental impact criteria are typically used for distinguishing between impacts for which color change is desired and impacts, e.g., of bodies other than the object, for which color change is not desired. The ID segment of the ISCC structure responds to the initiation signal, if provided, by causing the ID portion to temporarily appear as the changed color. When the ISCC structure contains IS and CC components, the ID segment of the IS component provides the impact signal if the threshold impact criteria are met. The ID segment of the CC component responds to the initiation signal, if provided, by causing the ID portion to temporarily appear as the changed color. 
     The activity can be tennis in which the object is a tennis ball. If so, the OI structure is incorporated into a tennis court for which the exposed surface has two baselines, two sidelines, two servicelines, and a centerline arranged conventionally. Each baseline, the sidelines, and the serviceline nearest that baseline define a backcourt so as to establish two backcourts. The present CC capability can be incorporated into various parts of the tennis court. For instance, the surface zone can be constituted with two VC backcourt area portions which partly occupy the backcourts and respectively adjoin the servicelines along largely their entire lengths. The CC capability is then used in determining whether served tennis balls are “in” or “out”. 
     The present CC capability enables a viewer to readily visually determine where the object impacted the exposed surface. The accuracy in determining the location of the print area is very high. A tennis player playing on a tennis court having the CC capability can, in the vast majority of instances, visually see whether a tennis ball impacting the court near a tennis line is “in” or “out”. Both the need to use challenges for reviewing line calls and the delay for line-call review are greatly reduced. The CC capability can be used in other sports, e.g., basketball, volleyball, football, and baseball/softball. While often a ball, the object can be implemented in other form such as a shoe of a person. The CC capability can also be used in activities other than sports. In short, the invention provides a very large advance over the prior art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1 and 2  are layout view of a standard tennis court with examples of areas where tennis balls contact the court&#39;s playing surface near the tennis lines indicated in  FIG. 2 . 
         FIGS. 3 and 4  are schematic diagrams of simulations of a tennis ball impacting a tennis court as determined by the Hawk-Eye system. 
         FIGS. 5 a -5 c    are layout views of an object-impact (“OI”) structure of an information-presentation (“IP”) structure embodiable or/and extendable according to the invention, the OI structure having a surface for being impacted by an object at an impact-dependent (“ID”) area and for changing color along a corresponding print area of a variable-color (“VC”) region. The cross section of each of  FIGS. 6 a , 11 a , 12 a , 13 a , 14 a , 15 a , 16 a , 17 a , 18 a , and 19 a    described below is taken through plane a 1 -a 1  in  FIG. 5 a   . The cross section of each of  FIGS. 6 b , 11 b , 12 b , 13 b , 14 b , 15 b , 16 b , 17 b , 18 b , and 19 b    described below is taken through plane b 1 -b 1  in  FIG. 5 b   . The cross section of each of  FIGS. 6 c , 11 c , 12 c , 13 c , 14 c , 15 c , 16 c , 17 c , 18 c , and 19 c    described below is taken through plane c 1 -c 1  in  FIG. 5   c.    
         FIGS. 6 a -6 c    are cross-sectional side views of an embodiment of the OI structure of  FIGS. 5 a   - 5   c.    
         FIGS. 7-9  are graphs of spectral radiosity as a function of wavelength. 
         FIG. 10  is a graph of a radiosity parameter as a function of time. 
         FIGS. 11 a -11 c , 12 a -12 c , 13 a -13 c , 14 a -14 c , 15 a -15 c , 16 a   - 16   c ,  17   a - 17   c ,  18   a - 18   c , and  19   a - 19   c  are cross-sectional side views of nine respective further embodiments of the OI structure of  FIGS. 5 a -5 c    according to the invention. 
         FIGS. 20 a  and 20 b  and 21 a  and 21 b    are respective cross-sectional side views of two variations of the OI structure of  FIGS. 5 a -5 c    according to the invention. The cross sections of  FIGS. 20 a  and 20 b    are respectively taken through planes a 1 -a 1  and b 1 -b 1  in  FIGS. 5 a  and 5 b    subject to deletion of the fixed-color region in the OI structure of  FIGS. 5 a  and 5 b   . The same applies to  FIGS. 21 a    and  21   b.    
         FIGS. 22 a  and 22 b    are additional layout views of the OI structure of  FIGS. 5 a -5 c    for different impact conditions than represented in  FIGS. 5 b    and  5   c.    
         FIGS. 23 a  and 23 b    are cross-sectional side views of the embodiment of the OI structures of  FIGS. 6 a -6 c    for the impact conditions respectively represented in  FIGS. 22 a  and 22 b   . The cross sections of  FIGS. 23 a  and 23 b    are respectively taken through planes a 2 -a 2  and b 2 -b 2  in  FIGS. 22 a    and  22   b.    
         FIGS. 24 a  and 24 b    are composite block diagrams/side cross-sectional views of two respective embodiments of the impact-sensitive color-change (“ISCC”) structure in the OI structure of  FIGS. 11 a -11 c    or  14   a - 14   c.    
         FIGS. 25 a  and 25 b    are composite block diagrams/side cross-sectional views of two respective embodiments of the ISCC structure in the OI structure of  FIGS. 12 a -12 c , 15 a -15 c , 17 a -17 c , 19 a -19 c   , or  21   a  and  21   b.    
         FIGS. 26 a  and 26 b , 27 a  and 27 b , 28 a  and 28 b , 29 a  and 29 b , 30 a  and 30 b , and 31 a    and  31   b  are cross-sectional side views showing how color changing occurs by light reflection in VC regions.  FIGS. 26 a  and 26 b    apply to the VC region in  FIGS. 6 a -6 c    or  20   a  and  20   b .  FIGS. 27 a  and 27 b    apply to the VC region in  FIGS. 11 a -11 c   .  FIGS. 28 a  and 28 b    apply to some embodiments of the VC region in  FIGS. 12 a -12 c    or  21   a  and  21   b .  FIGS. 29 a  and 29 b    apply to the VC region in  FIGS. 13 a -13 c   .  FIGS. 30 a  and 30 b    apply to the VC region in  FIGS. 14 a -14 c   .  FIGS. 31 a  and 31 b    apply to some embodiments of the VC region in  FIGS. 15 a   - 15   c.    
         FIGS. 32 a  and 32 b , 33 a  and 33 b , 34 a  and 34 b , 35 a  and 35 b , 36 a  and 36 b , and 37 a    and  37   b  are cross-sectional side views showing how color changing occurs by light emission in VC regions.  FIGS. 32 a  and 32 b    apply to the VC region in  FIGS. 6 a -6 c    or  20   a  and  20   b .  FIGS. 33 a  and 33 b    apply to the VC region in  FIGS. 11 a -11 c   .  FIGS. 34 a  and 34 b    apply to the VC region in  FIGS. 12 a -12 c    or  21   a  and  21   b .  FIGS. 35 a  and 35 b    apply to the VC region in  FIGS. 13 a -13 c   .  FIGS. 36 a  and 36 b    apply to the VC region in  FIGS. 14 a -14 c   .  FIGS. 37 a  and 37 b    apply to the VC region in  FIGS. 15 a   - 15   c.    
         FIGS. 38 a  and 38 b    are layout views of a cellular embodiment of the OI structure of  FIGS. 5 a -5 c    according to the invention. The cross section of each of  FIGS. 41 a , 42 a , 43 a , 44 a , 45 a , 46 a , 47 a , 48 a , 49 a , and 50 a    described below is taken through plane a 3 -a 3  in  FIG. 38 a   . The cross section of each of  FIGS. 41 b , 42 b , 43 b , 44 b , 45 b , 46 b , 47 b , 48 b , 49 b , and 50 b    described below is taken through plane b 3 -b 3  in  FIG. 38   b.    
         FIGS. 39 a  and 39 b    are diagrams of exemplary quantized print areas within circular object-contact areas for the OI structure of  FIGS. 38 a    and  38   b.    
         FIG. 40  is a graph of the ratio of the difference in area between a true circle and a quantized circle as a function of the ratio of the radius of the true circle to the length/width dimension of identical squares forming the quantized circle. 
         FIGS. 41 a  and 41 b , 42 a  and 42 b , 43 a  and 43 b , 44 a  and 44 b , 45 a  and 45 b , 46 a    and  46   b ,  47   a  and  47   b ,  48   a  and  48   b ,  49   a  and  49   b , and  50   a  and  50   b  are cross-sectional side views of ten respective embodiments of the OI structure of  FIGS. 38 a    and  38   b.    
         FIG. 51  is an expanded cross-sectional view of an embodiment of the cellular ISCC structure in the OI structure of  FIGS. 41 a  and 41 b , 44 a  and 44 b , 47 a  and 47 b   , or  49   a  and  49   b.    
         FIG. 52  is an expanded cross-sectional view of an embodiment of the cellular ISCC structure in the OI structure of  FIGS. 42 a  and 42 b    or  45   a  and  45   b.    
         FIG. 53  is an expanded cross-sectional view of an embodiment of the cellular ISCC structure in the OI structure of  FIGS. 43 a  and 43 b    or  46   a  and  46   b.    
         FIGS. 54 a  and 54 b    are composite block diagrams/layout views of an IP structure containing an OI structure having a surface for being impacted by an object at an ID area and for changing color along a corresponding print area of a VC region under control of a duration controller for adjusting color-change (“CC”) duration according to the invention. 
         FIGS. 55-58  are composite block diagrams/side cross-sectional views of four respective embodiments of the IP structure of  FIGS. 54 a  and 54 b    according to the invention. The cross section of the layout portion of each of  FIGS. 55-58  is taken through plane b 4 -b 4  in  FIG. 54   b.    
         FIGS. 59 a  and 59 b    are composite block diagrams/layout views of an IP structure containing an OI structure having a surface for being impacted by an object at an ID area and for changing color along a corresponding print area of a cellular VC region under control of a duration controller for extending CC duration according to the invention. 
         FIGS. 60-63  are composite block diagrams/side cross-sectional views of four respective embodiments of the IP structure of  FIGS. 59 a  and 59 b    according to the invention. The cross section of the layout portion of each of  FIGS. 60-63  is taken through plane b 5 -b 5  in  FIG. 59   b.    
         FIGS. 64 a  and 64 b    are composite block diagrams/layout views of an IP structure containing an OI structure having a surface for being impacted by an object at an ID area and for changing color along a corresponding print area of a VC region under control of an intelligent controller according to the invention. 
         FIGS. 65-68  are composite block diagrams/side cross-sectional views of four respective embodiments of the IP structure of  FIGS. 64 a  and 64 b    according to the invention. The cross section of the layout portion of each of  FIGS. 65-68  is taken through plane b 6 -b 6  in  FIG. 64   b.    
         FIGS. 69 a  and 69 b    are composite block diagrams/layout views of an IP structure containing an OI structure having a surface for being impacted by an object at an ID area and for changing color along a corresponding print area of a cellular VC region under control of an intelligent controller according to the invention. 
         FIGS. 70-73  are composite block diagrams/side cross-sectional views of four respective embodiments of the IP structure of  FIGS. 69 a  and 69 b    according to the invention. The cross section of the layout portion of each of  FIGS. 70-73  is taken through plane b 7 -b 7  in  FIG. 69   b.    
         FIGS. 74-77  are composite block diagrams/perspective cross-sectional views of four respective IP structures, each containing an OI structure having a surface for being impacted by an object at an ID area and for changing color along a corresponding print area of a VC region and also having an image-generating capability according to the invention. 
         FIGS. 78 a  and 78 b    are layout views of an OI structure having a surface for being impacted by an object at an ID area and for changing color along a corresponding print area of one or both of two adjoining VC regions according to the invention. 
         FIGS. 79 a  and 79 b    are layout views of an OI structure having a surface for being impacted by an object at an ID area and for changing color along a corresponding print area of one or more of three consecutively adjoining VC regions according to the invention. The cross section of each of  FIGS. 80 a , 81 a , 82 a , 83 a , 84 a , and 85 a    described below is taken through plane a 8 -a 8  in  FIG. 79 a   . The cross section of each of  FIGS. 80 b , 81 b , 82 b , 83 b , 84 b , and 85 b    described below is taken through plane b 8 -b 8  in  FIG. 79 b   . Label a 8 * in each of  FIGS. 80 a , 81 a , 82 a , 83 a , 84 a , and 85 a    indicates the location of a cross section taken through plane a 8 *-a 8 * in  FIG. 78 a   . Label b 8 * in each of  FIGS. 80 b , 81 b , 82 b , 83 b , 84 b , and 85 b    indicates the location of a cross section taken through plane b 8 *-b 8 * in  FIG. 78   b.    
         FIGS. 80 a  and 80 b , 81 a  and 81 b , 82 a  and 82 b , 83 a  and 83 b , 84 a  and 84 b , and 85 a    and  85   b  are cross-sectional side views of six respective embodiments of the OI structure of  FIGS. 79 a    and  79   b.    
         FIGS. 86 a  and 86 b    are layout views of an OI structure having a surface for being impacted by an object at an ID area and for changing color along a corresponding print area of one or both of two adjoining cellular VC regions according to the invention. 
         FIGS. 87 a  and 87 b    are layout views of an OI structure having a surface for being impacted by an object at an ID area and for changing color along a corresponding print area of one or more of three consecutively adjoining cellular VC regions according to the invention. 
         FIGS. 88 and 89  are composite block diagrams/layout views of two respective IP structures, each containing an OI structure having a surface for being impacted by an object at an ID area and for changing color along a corresponding print area of one or more of three consecutively adjoining VC regions under control of a CC controller according to the invention. 
         FIGS. 90-93  are composite block diagrams/perspective cross-sectional views of four respective IP structures, each containing an OI structure having a surface for being impacted by an object at an ID area and for changing color along a corresponding print area of one or more of three consecutively adjoining VC regions and having an image-generating capability according to the invention. 
         FIGS. 94 a -94 d    are layout views of four respective examples of the object-contact location and resultant print area for the object variously impacting the surface in the OI structures of  FIGS. 5 a  and 5 b , 78 a  and 78 b , and 79 a    and  79   b.    
         FIGS. 95 a -95 d    are screen views of smooth-curve approximations, according to the invention, of the print area and nearby surface area respectively for the examples of  FIGS. 94 a   - 94   d.    
         FIGS. 96 and 97  are layout views of two respective exemplary embodiments of an IP structure implemented into a tennis court according to the invention. 
         FIGS. 98-100  are layout views of exemplary embodiments of an IP structure respectively implemented into a basketball court, a volleyball court, and a football field according to the invention. 
         FIG. 101  is a perspective view of an exemplary embodiment of an IP structure implemented into a baseball or softball field according to the invention. 
         FIGS. 102 a  and 102 b    are cross-sectional views of two models of a hollow ball impacting an inclined surface. 
     
    
    
     Like reference symbols are employed in the drawings and in the description of the preferred embodiments to represent the same, or very similar, item or items. 
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
                             Table of Contents                                    Preliminary Material       Basic Object-impact Structure Having Variable-color Region       Timing and Color-difference Parameters       Object-impact Structure Having Variable-color Region Formed with Impact-sensitive                         Changeably Reflective or Changeably Emissive Material                 Object-impact Structure Having Separate Impact-sensitive and Color-change Components       Object-impact Structure Having Impact-sensitive Component and Changeably Reflective or                         Changeably Emissive Color-change Component                 Object-impact Structure Having Impact-sensitive Component and Color-change Component                         that Utilizes Electrode Assembly                 Configuration and General Operation of Electrode Assembly       Electrode Layers and their Characteristics and Compositions       Reflection-based Embodiments of Color-change Component with Electrode Assembly       Emission-based Embodiments of Color-change Component with Electrode Assembly       Object-impact Structure Having Surface Structure for Protection, Pressure Spreading, and/or                         Velocity Restitution Matching                 Object-impact Structure Having Deformation-controlled Extended Color-change Duration       Equation-form Summary of Light Relationships       Transmissivity Specifications       Manufacture of Object-impact Structure       Object-impact Structure with Print Area at Least Partly around Unchanged Area       Configurations of Impact-sensitive Color-change Structure       Pictorial Views of Color Changing by Light Reflection and Emission       Object-impact Structure with Cellular Arrangement       Adjustment of Changed-state Duration       Intelligent Color-change Control       Image Generation and Object Tracking       Multiple Variable-color Regions       Curve Smoothening       Color Change Dependent on Location in Variable-color Region of Single Normal Color       Sound Generation       Accommodation of Color Vision Deficiency       Tennis Implementations       Other Sports Implementations       Velocity Restitution Matching       Variations                    
Preliminary Material
 
     The visible light spectrum extends across a wavelength range specified as being as narrow as 400-700 nm to as wide as 380-780 nm. Light in the visible wavelength range produces a continuous variation in spectral color from violet to red. A visible color is black, any spectral color, and any color creatable from any combination of spectral colors. For instance, visible color includes white, gray, brown, and magenta because each of them is creatable from spectral colors even though none of them is itself in the visible spectrum. Further recitations of color or light herein mean visible color or visible light. Radiation in the ultraviolet and infrared spectra are respectively hereafter termed ultraviolet (“UV”) and infrared (“IR”) radiation. 
     Various wavelength ranges are reported for the main spectral colors. Although indigo or/and cyan are sometimes identified as main spectral colors, the main spectral colors are here considered to be violet, blue, green, yellow, orange, and red having the wavelength ranges presented in Table 1 and determined as the averages of the ranges reported in ten references rounded off to the nearest 5 nm using the maximum specified range of 380-780 nm for the visible spectrum. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Color 
                 Wavelength Range (nm) 
               
               
                   
                   
               
             
            
               
                   
                 Violet 
                 380-445 
               
               
                   
                 Blue 
                 445-490 
               
               
                   
                 Green 
                 490-570 
               
               
                   
                 Yellow 
                 570-590 
               
               
                   
                 Orange 
                 590-630 
               
               
                   
                 Red 
                 630-780 
               
               
                   
                   
               
            
           
         
       
     
     Recitations of light striking, or incident on, a surface of a body mean that the light strikes, or is incident on, the surface from outside the body. The color of the surface is determined by the wavelengths of light leaving the surface and traveling away from the body. Such light variously consists of incident light reflected by the body so as to leave it along the surface, light emitted by the body so as to leave it along the surface, and light leaving the body along the surface after entering the body along one or more other surfaces and passing through the body. Even if the characteristics that define the color of the surface are fixed, its color can differ if it is struck by light of different wavelength characteristics. For instance, the surface appears as one color when struck by white light but as another color when struck by non-white light. 
     If a person directly views the body, the color of the surface is directly determined by the wavelengths of the light traveling from the surface to the person&#39;s eye(s) and the brain&#39;s interpretation of those wavelengths. If an image of the surface is captured by a color camera whose captured image is later viewed by a person, the surface&#39;s color is initially established by the wavelengths of the light traveling from the surface to the camera. The surface&#39;s color as presented in the image is then determined by the wavelengths of the light traveling from the image to the person&#39;s eye(s) and the brain&#39;s interpretation of those wavelengths. In either case, the wavelengths of light leaving the surface define its color subject, for the camera, to any color distortion introduced by the camera. 
     The radiosity, sometimes termed intensity, of light of a particular color is the total power per unit area of that light leaving a body along a surface. The spectral radiosity of light of a particular color is the total power per unit area per unit wavelength at each wavelength of light leaving a body along a surface. The spectral radiosity constituency (or spectral radiosity profile) of light of a particular color is the variation (or distribution) of spectral radiosity as a function of wavelength and defines the wavelength constituency of that light. Inasmuch as the spectral radiosity of light is zero outside the visible spectrum, the radiosity of light of a particular color is the integral of the spectral radiosity constituency across the visible spectrum. 
     Two colors differ when their spectral radiosity constituencies differ. The spectrum-integrated absolute spectral radiosity difference between light of two different colors is the integral of the absolute value of the difference between the spectral radiosities of the two colors across the visible spectrum. For light passing through a body, the spectral radiosity of light leaving it may differ from that of light entering it due to phenomena such as light absorption in the body. For instance, if light appears as a shade of a color upon entering a body and if the light&#39;s radiosity decreases in passing through the body, the light appears as a lighter shade of that color upon leaving the body. When light leaving a body along a surface of the body has multiple reflected components, each reflected component differs from each other reflected component because the light reflected by each reflected component causes its spectral radiosity constituency to differ from the spectral radiosity constituency of each other reflected component. 
     The normalized spectral radiosity of light of a particular color is its spectral radiosity divided by its radiosity. The normalized spectral radiosity constituency of light of a particular color is the variation of its normalized spectral radiosity as a function of wavelength. The integral of the normalized spectral radiosity constituency across the visible spectrum is one. For light passing through a body, use of the same reference nomenclature to identify the light leaving the body as used to identify the light entering it means that the normalized spectral radiosity constituency remains essentially the same during passage through the body even though the spectral radiosity constituency may change during the passage. This convention is used below for light undergoing plane polarization in passing through a body. 
     Rods and cones in the human eye are sensitive to incoming light. Rods are generally sensitive to the radiosity of the light. Cones are generally sensitive to its spectral radiosity and thus to its wavelength constituency. Cones consist of (a) short-wavelength, or “blue”, cones sensitive to light typically in the wavelength range of 380-520 nm with a typical peak sensitivity at 420-440 nm, (b) medium-wavelength, or “green”, cones sensitive to light typically in the wavelength range of 440-650 nm with a typical peak sensitivity at 535-555 nm, and (c) long-wavelength, or “red”, cones sensitive to light typically in the wavelength range of 480-780 nm with a typical peak sensitivity at 565-580 nm. As this data indicates, the sensitivity ranges overlap considerably, especially for green and red cones. Electrical impulses indicative of the stimulation of rods and cones by light are supplied to the brain which interprets the impulses to assign an appropriate color pattern to the light. 
     Light entering the human eye at a wavelength in the medium-wavelength range commonly stimulates at least two of the three types of cones and often all three types. An example clarifies this. Light in the yellow range, largely 570-590 nm, stimulates red and green cones so that the brain interprets the impulses from the rods and red and green cones as yellow. Assume that the eye receives equal intensities of light in the green range, largely 490-570 nm, and the red range, largely 630-780 nm, for stimulating red and green cones the same as the light in the yellow range. The brain interprets the electrical impulses from the rods and red and green cones as yellow. Except for the colors at the ends of the visible spectrum, there is normally a continuous regime of suitable combinations for creating any color dependent on wavelength and radiosity. 
     A recitation that two or more colors materially differ herein means that the colors differ materially as viewed by a person of standard (or average) eyesight/brain-processing capability. The verb “appear”, including grammatical variations such as “appearing”, as used herein for the chromatic characteristics of light means its apparent color as perceived by the standard human eye/brain. A recitation that a body appears along a surface of the body as a specified color means that the body appears along the surface “largely” as that color. In particular, the spectral radiosity constituency of light of the specified color may so vary across the surface that the specified color is a composite of different colors. The surface portions from where light of wavelengths suitable for the different colors leave the body are usually so microscopically distributed among one another or/and occupy area sufficiently small that the standard human eye/brain interprets that light as essentially a single color. 
     A “species” of light means light having a particular spectral radiosity constituency. Although a light species produces a color when only light of that species leaves a surface of a body, only some of the below-described light species are described as being of wavelength suitable for forming colors. A recitation that multiple species of the total light leaving a body along a surface area form light of wavelength suitable for a particular color also means that the body appears along the area as that color. A recitation that light leaves a body along an adjoining body means that the light leaves the first body along the interface between the two bodies and vice versa. When all the light leaving a body along an internal interface with another body is of wavelength suitable for a selected color, the first body would visually appear as the selected color along the interface if it were an exposed surface. 
     Each color identified below by notation beginning with a letter, e.g., “A” or “X”, means a selected color. Each such selected color may be a single color or a combination of colors appearing as a single color due to suitable mixture of light of wavelengths of those colors. The expression “light of wavelength” means one or more subranges of the wavelength range of the visible spectrum. When a particular color is identified by reference notation, the terminology consisting of that reference notation followed by the word “light” means a species of light of wavelength of that color, i.e., suitable for forming that color. For instance, “V light” means a species of light of wavelength suitable for forming color V. A recitation that two or more colors differ means that light of those colors differs. If the colors are indicated as differing in a particular way, e.g., usually or materially, the light of those colors differ in the same way. 
     Instances occur in which a body is described as reflecting or emitting light of wavelength of a selected color. Letting that light be termed the “selected color light”, the reflection or emission of the selected color light may occur generally along a surface of the body, i.e., directly at the surface or/and at locations internal to the body within short distances of the surface such that the reflected or emitted light does not undergo significant attenuation in traveling those short distances. The body may be sufficiently transmissive of the selected color light that it is alternatively or additionally reflected or emitted inside the body at substantial distances away from the surface and undergoes significant attenuation before exiting the body via the surface. Light striking a body and not reflected by it is absorbed or/and transmitted by it. 
     The term “encompasses” means is common to (or includes), usually along a surface. For instance, a first item partly encompasses a second item when part of the area of the second item along a suitable surface is common to the first item. A description of an essentially two-dimensional first item as “outwardly conforming” to an essentially two-dimensional second item means that the perimeter of the first item, or the outer perimeter of the first item if it is shaped, e.g., as an annulus, to have outer and inner perimeters relative to its center, conforms to the perimeter of the second item, or to the outer perimeter of the second item if it is likewise shaped to have outer and inner perimeters relative to its center. 
     A “thickness location” of a body means a location extending largely fully through the body&#39;s thickness. There are instances in which the transmissivity of a body at one or more thickness locations to light perpendicularly incident on the body at at least wavelength suitable for one or more selected colors is presented as a group of transmissivity specifications. These transmissivity specifications include a usual minimum value for the body&#39;s transmissivity to light perpendicularly incident on a surface of the body at wavelength suitable for a selected color where the body normally visually appears along the surface as a principal color and where an impact-dependent print area of the surface changes color in response to an object impacting the surface at an object-contact area generally outwardly conforming to the print area so that it temporarily appears as changed color materially different from the principal color. 
     The body may have thickness locations where the transmissivity of the perpendicularly incident light is less than the usual minimum. If so, the corresponding locations along the surface still normally appear as the principal color due to phenomena such as light scattering and non-perpendicular light reflection and by arranging for such thickness locations to be sufficiently laterally small that their actual colors are not significantly perceivable by the standard human eye/brain. Any such corresponding locations along the print area similarly temporarily appear as the changed color. The body meets the requisite color appearances along the surface, including the print area, even though the body&#39;s transmissivity to the incident light is less than the usual minimum at one or more thickness locations. 
     Material is transparent if the shape of a body separated from the material only by air or vacuum can be clearly and accurately seen through the material. The material is transparent even if the body&#39;s shape is magnified or shrunk as seen through the material. Transparent material is clear transparent if the color(s) of the body as seen through the material are the same as the body&#39;s actual color(s). Transparent material is tinted transparent if the color(s) of the body as seen through the material differ from the body&#39;s actual color(s) due to tinting light reflection by the material. 
     Various instances are described below in which light incident on the first region of a body containing first and second regions is partly reflected and partly transmitted by the first region so as to be incident on the second region which at least partly reflects the transmitted light. The light reflected by the first region is of wavelength suitable for a first color. The light reflected by the second region is of wavelength suitable for a second color. Even if not explicitly stated, the two colors necessarily differ because light reflection by the first region causes the spectral radiosity constituency of the second color to lack at least part of the spectral radiosity constituency of the first color and thus to differ from the spectral radiosity constituency of the first color. If the two regions have identical reflection characteristics, the second color is black because the first region reflects the light needed for the second color to be non-black. 
     The term “impact-dependent” as used in describing a three-dimensional region or a surface area means that the lateral extent of the region or area depends on the lateral extent of the location where an object impacts the region or area. Impact-dependent segments of auxiliary layers, electrode assemblies, electrode structures, and core layers are often respectively described below as auxiliary segments, assembly segments, electrode segments, and core segments. 
     An “arbitrary” shape means any shape and includes shapes not significantly restricted to a largely fixed characteristic, such as a largely fixed dimension, along the shape. An arbitrary shape is not limited to one or more predefined shapes such as polygons, regular closed curves, and finite-width lines, straight or curved. Recitations of an action occurring “along” a body or along a surface of a body mean that the action occurs within a short distance of the surface, often inside the body, and not necessarily at the surface. The expressions “situated fully along”, “lying fully along”, “extending fully along”, and grammatical variations mean adjoining along substantially the entire length (of). 
     The words “overlying” and “underlying” used below in describing structures apply to the orientations of those structures as shown in the drawings. The same applies to “over”, “above, “under”, and “below” as used in a directional sense in describing such structures. These six words are to be interpreted to mean corresponding other directional-sense words for structures configured identical to, but oriented differently than, those shown in the drawings. 
     A majority component of a multi-component item is a component constituting more than 50% of the item according to a suitable measurement. An N % majority component of a multi-component item is a component constituting at least N % of the item where N is a number greater than 50. Each provision that light of a first species is a (or the) majority component of light of a second species means that the light of the first species is radiositywise, i.e., in terms of radiosity, a (or the) majority component of light of the second species. A majority component of a color means radiositywise a majority component of light forming that color. The percentage difference between two values of a parameter means the quotient, converted to percent, of their difference and average. 
     The term “normally” refers to actions occurring during the normal state, explained below, in the object-impact structures of the invention, e.g., the expression “normally appears” means visually appears during the normal state. Other time-related terms, such as “usually” and “typically”, are used to describe actions occurring during the normal state but not limited to occurring during the normal state. The term “temporarily” refers to actions occurring during the changed state, defined below, in the object-impact structures, e.g., the expression “temporarily appears” means visually appears during the changed state. Force acting on a body normal, i.e., perpendicular, to a surface where it is contacted by the body, is termed “orthogonal” force herein to avoid confusion with the meaning of “normal” otherwise used herein. 
     The term “or/and” or “and/or” between a pair of items means either or both items. Similarly, “or/and” or “and/or” before the next-to-last item of three or more items means any one or more, up to all, of the items. Use of multiple groups of items in a sentence where each group of items has an “or” before the last item in that group means, except as the context otherwise indicates, that the first items in the groups are associated with each other, that the second items in the groups are associated with each other, and so on. For instance, a recitation of the form “Item J1, J2, or J3 is connected to item K1, K2, or K3” means that item J1 is connected to item K1, item J2 is connected to item K2, and item J3 is connected to item K3. The plural term “criteria” is generally used below to describe the various types of standards used in the invention because each type of standards is generally capable of consisting of multiple standards. 
     All recitations of the same, uniform, identical, a single, singly, full, only, constant, fixed, all, the entire, straight, flat, planar, parallel, perpendicular, conform, continuous, adjacent, adjoin, opposite, symmetrical, mirror image, simultaneous, independent, transparent, block, absorb, non-emissive, passive, prevent, absent, and grammatical variations ending in “ly” respectively mean largely the same, largely uniform, largely identical, largely a single, largely singly, largely fully, largely only, largely constant, largely fixed, largely all, largely the entire, largely straight, largely flat, largely planar, largely parallel, largely perpendicular, largely conform, largely continuous, largely adjacent, largely adjoin, largely opposite, largely symmetrical, largely mirror image, largely simultaneous, largely independent, largely transparent, largely block, largely absorb, largely non-emissive, largely passive, largely prevent, largely absent, and “largely” followed by the variations ending in “ly” except as otherwise indicated. A recitation that multiple light species form a further light species includes the meaning that the multiple species largely form the further light species. Each recitation providing that later textual material is the same as earlier textual material means that the earlier material is incorporated by reference into the later material. 
     Each signal described below as being transmitted via a communication path, e.g., in a network of communication paths, is transmitted wirelessly or via one or more electrical wires of that communication path. A recitation that a body undergoes a change in response to a signal means that that the change occurs due to a change in a variable, e.g., current and voltage, in which the signal exists. Light provided from a particular source or in a particular way such as emission or reflection may be viewed as a light beam. Light provided from multiple sources or in multiple ways may be viewed as multiple light beams. 
     The terms “conductive”, “resistive”, and “insulating” respectively mean electrically conductive, electrically resistive, and electrically insulating except as otherwise indicated. A material having a resistivity less than 10 ohm-cm at 300° K (approximately usual room temperature) is deemed to be conductive. A material having a resistivity greater than 10 10  ohm-cm at 300° K is deemed to be insulating (or dielectric). A material having a resistivity from 10 ohm-cm to 10 10  ohm-cm at 300° K is deemed to be resistive. Resistive materials conduct current with the conduction capability progressively increasing as the resistivity decreases from 10 10  ohm-cm to 10 ohm-cm at 300° K. Inasmuch as conductivity is the inverse of resistivity, conductivity-based criteria are numerically the inverse of resistivity-based criteria. 
     The order in which the elements of an inorganic chemical compound appear below in the compound&#39;s chemical name or/and chemical formula generally follows the standards of the International Union of Pure and Applied Chemistry (“IUPAC”). That is, a more electronegative element follows a less electronegative element in the name and formula of an inorganic compound. In some situations, use of the IUPAC element-ordering convention for inorganic compounds results in element orderings different from that generally or sometimes used. Such situations are accommodated herein by presenting other orderings of the chemical formulas in brackets following the IUPAC chemical formulas. 
     The following acronyms are used as adjectives below to shorten the description. “AB” means assembly. “ALA” means attack-line-adjoining. “ALV” means attack-line-vicinity. “BC” means backcourt. “BLA” means baseline-adjoining. “BP” means beyond-path. “BV” means boundary-vicinity. “CC” means color-change. “CE” means changeably emissive. “CI” means characteristics-identifying. “CLA” means centerline-adjoining. “CM” means criteria-meeting. “COM” means communication. “CR” means changeably reflective. “DE” means duration-extension. “DF” means deformation. “DP” means distributed-pressure. “ELA” means endline-adjoining or end-line-adjoining. “EM” means electromagnetic. “FA” means far auxiliary. “FC” means fixed-color. “FE” means far electrode. “FLT” means foul-territory. “FLV” means foul-line-vicinity. “FRT” means fair-territory. “GAB” means general assembly. “GFA” means general far auxiliary. “HA” means half-alley. “IB” means inbounds. “ID” means “impact-dependent”. “IDVC” means impact-dependent variable-color. “IF” means interface. “IG” means image-generating. “IP” means information-presentation. “IS” means impact-sensitive. “ISCC” means impact-sensitive color-change. “LA” means line-adjoining. “LC” means liquid-crystal. “LE” means light-emissive. “LI” means location-identifying. “NA” means near auxiliary. “NE” means near electrode. “OB” means out-of-bounds. “OC” means object-contact. “OI” means object-impact. “OS” means object-separation. “OT” means object-tracking. “PA” means print-area. “PAV” means print-area vicinity. “PS” means pressure-spreading. “PSCC” means pressure-sensitive color-change. “PZ” means polarization. “RA” means reflection-adjusting. “QC” means quartercourt. “SC” means servicecourt. “SF” means surface. “SLA” means sideline-adjoining or side-line-adjoining. “SS” means surface-structure. “SVLA” means serviceline-adjoining. “TH” means threshold. “VA” means voltage-application. “VC” means variable-color. “WI” means wavelength-independent. “XN” means transition. “3P” means three-point. “3PL” means three-point-line. “3PLV” means three-point-line-vicinity. 
     Basic Object-Impact Structure Having Variable-Color Region 
       FIGS. 5 a -5 c    (collectively “ FIG. 5 ”) illustrate the layout of a basic object-impact structure  100  which undergoes reversible color changes along an externally exposed surface  102  according to the invention when exposed surface  102  is impacted by an object  104  during an activity such as a sport. “OI” hereafter means object-impact. “Impact” hereafter means impact of object  104  on surface  102 .  FIG. 5 a    presents the general layout of OI structure  100 .  FIGS. 5 b  and 5 c    depict exemplary color changes that occur along surface  102  due to the impact. Object  104  leaves surface  102  subsequent to impact and is indicated in dashed line in  FIGS. 5 b  and 5 c    at locations shortly after impact. Although object  104  is often directed toward particular locations on surface  102 , object  104  can generally impact anywhere on surface  102 . 
     Object  104  is typically airborne and separated from other solid matter prior to impact. For a sports activity, object  104  is typically a sports instrument such as a spherical ball, e.g., a tennis ball, basketball, or volleyball when the activity is tennis, basketball, or volleyball. Object  104  can, however, be part of a larger body that may not be airborne prior to impact. For instance, object  104  can be a shoe on a foot of a person such as a tennis, basketball, or volleyball player. Different embodiments of OI structure  100  can be employed, usually in different parts of surface  102 , so that the embodiments of object  104  differ from OI embodiment to OI embodiment. 
     OI structure  100 , which serves as or in an information-presentation structure, is used in determining whether object  104  impacts a specified zone of surface  102 . In this regard, structure  100  contains a principal variable-color region  106  and a secondary fixed-color region  108  which meet at a region-region interface  110 . “VC” and “FC” hereafter respectively mean variable-color and fixed-color. Although interface  110  appears straight in  FIG. 5 , VC region  106  and FC region  108  can be variously geometrically configured along interface  110 , e.g., curved, or flat and curved. They can meet at corners. FC region  108  can extend partly or fully laterally around VC region  106  and vice versa. For instance, region  108  can adjoin region  106  along two or more sides of region  106  if it is shaped laterally like a polygon and vice versa. 
     VC region  106  extends to surface  102  at a principal VC surface zone  112  and normally appears along it as a principal surface color A during the activity. See  FIG. 5 a   . “SF” hereafter means surface. This occurs because only A light normally leaves region  106  along SF zone  112 . Region  106  is then in a state termed the “normal state”. Recitations hereafter of (a) region  106  normally appearing as principal SF color A mean that region  106  normally appears along zone  112  as color A, (b) A light leaving region  106  mean that A light leaves it via zone  112 , and (c) colors and color changes respectively mean colors present, and color changes occurring, during the activity. Region  106  contains principal impact-sensitive color-change structure along or below all of zone  112 . “ISCC” hereafter means impact-sensitive color-change. Examples of the ISCC structure, not separately indicated in  FIG. 5 , are described below and shown in later drawings. Region  106  may contain other structure described below. 
     FC region  108 , which extends to surface  102  at a secondary FC SF zone  114 , fixedly appears along FC SF zone  114  as a secondary SF color A′. Secondary SF color A′ is often the same as, but can differ significantly from, principal color A. Region  108  can consist of multiple secondary FC subregions extending to zone  114  so that consecutive ones appear along zone  114  as different secondary colors A′. Except as indicated below, region  108  is hereafter treated as appearing along zone  114  as only one color A′. SF zones  112  and  114  meet at an SF edge of interface  110 . 
     An impact-dependent portion of VC region  106  responds to object  104  impacting SF zone  112  at a principal impact-dependent object-contact area  116  (laterally) spanning where object  104  contacts (or contacted) zone  112  by temporarily appearing along a corresponding principal impact-dependent print area  118  of zone  112  as a generic changed SF color X (a) in some general OI embodiments if the impact meets (or satisfies) principal basic threshold impact criteria or (b) in other general OI embodiments if region  106 , specifically the impact-dependent portion, is provided with a principal general color-change control signal generated in response to the impact meeting the principal basic threshold impact criteria sometimes (conditionally) dependent on other impact criteria also being met in those other embodiments. See  FIGS. 5 b  and 5 c   . “ID”, “OC”, “TH”, and “CC” hereafter respectively mean impact-dependent, object-contact, threshold, and color-change. The ID portion of region  106  is hereafter termed the principal IDVC portion where “IDVC” hereafter means impact-dependent variable-color. Instances in which the principal IDVC portion, often simply the IDVC portion, changes to appear as generic changed SF color X along ID print area  118  in response to the principal general CC control signal are described below, particularly beginning with the structure of  FIGS. 64 a    and  64   b.    
     ID OC area  116  is capable of being of substantially arbitrary shape. Print area  118  constitutes part of zone  112 , all of which is capable of temporarily appearing as generic changed SF color X. Print area  118  closely matches OC area  116  in size, shape, and location. In particular, print area  118  at least partly encompasses OC area  116 , at least mostly, usually fully, outwardly conforms to it, and is largely concentric with it. The principal basic TH impact criteria can vary with where print area  118  occurs in zone  112 . 
     When VC region  106  includes structure besides the ISCC structure, an ID segment of the ISCC structure specifically responds to object  104  impacting OC area  116  by causing the IDVC portion to temporarily appear along print area  118  as changed color X (a) in some general OI embodiments if the impact meets the basic TH impact criteria or (b) in other general OI embodiments if the ID ISCC segment is provided with the general CC control signal generated in response to the impact meeting the basic TH impact criteria again sometimes dependent on other impact criteria also being met in those other embodiments. In any event, the appearance of the IDVC portion along area  118  as changed SF color X occurs because only X light temporarily leaves the IDVC portion along area  118 . Color X differs materially from color A and usually from color A′. Hence, X light differs materially from A light. Recitations hereafter of (a) the IDVC portion temporarily appearing as color X mean that the IDVC portion temporarily appears along area  118  as color X and (b) X light leaving the IDVC portion mean that X light leaves it via area  118 . 
     Importantly, the impact usually leads to color change along surface  102  only at print area  118  closely matching OC area  116  in size, shape, and location. Although other impacts of object  104  may cause color change at other locations along surface  102 , a particular impact of object  104  usually does not lead to, and is usually incapable of leading to, color change at any location along surface  102  other than print area  118  for that impact. Persons viewing surface  102  therefore need essentially not be concerned about a false color change along surface  102 , i.e., a color change not accurately representing area  116 . 
     The spectral radiosity constituency of A light may vary across SF zone  112 . That is, principal color A may be a composite of different colors such as primary colors red, green, and blue. The parts of zone  112  from where light of wavelengths for the different colors leaves zone  112  are usually so microscopically distributed among one another that the standard human eye/brain interprets that light as essentially a single color. 
     The spectral radiosity constituency of X light may similarly vary across print area  118  so that changed color X is also a composite of different colors. One color in such a color X composite may be color A or, if it is a composite of different colors, one or more colors in the color X composite may be the same as one or more colors in the color A composite. If so, the parts of area  118  from where light of wavelengths for the different colors in the color X composite leaves area  118  are so microscopically distributed among one another that, across area  118 , the standard human eye/brain does not separately distinguish color A or any color identical to a color in the color A composite. Color X, specifically the color X composite, still differs materially from color A despite the color X composite containing color A or a color identical to a color in the color A composite. 
     The principal basic TH impact criteria consist of one or more TH impact characteristics which the impact must meet for the IDVC portion to temporarily appear as color X. There are two primary locations for assessing the impact&#39;s effects to determine whether the TH impact criteria are met: (i) directly at SF zone  112  and (ii) along a plane, termed the internal plane, extending laterally through VC region  106  generally parallel to, and spaced apart from, zone  112 . In either case, the impact is typically characterized by an impact parameter P that varies between a perimeter (first) value P pr  and an interior (second) value P in . For zone  112 , perimeter value P pr  exists along the perimeter of OC area  116  while interior value P in  exists at one or more points inside area  116 . For the internal plane, perimeter value P pr  exists along the perimeter of a projection of area  116  onto the internal plane while interior value P in  exists at one or more points inside that projection. Area  116  and the projection can differ in size as long as a line extending perpendicular to area  116  through its center also extends perpendicular to the projection through its center. The difference ΔP max  between values P pr  and P in  is the absolute value of the maximum difference between any two values of impact parameter P across area  116  or the projection. 
     For the situation in which the IDVC portion temporarily appears as changed color X if the impact meets the basic TH impact criteria and thus momentarily putting aside the situation dealt with further below in which the IDVC portion temporarily appears as color X if the ID ISCC segment is provided with the general CC control signal generated in response to both the TH impact criteria and other impact criteria being met, the TH impact criteria are met at each point, termed a criteria-meeting point, inside OC area  116  or the projection of area  116  where the absolute value ΔP of the difference between impact parameter P and perimeter value P pr  equals or exceeds a local TH value ΔP thl  of parameter difference ΔP. “CM” hereafter means criteria-meeting. Local TH parameter difference value ΔP thl  lies between zero and maximum parameter difference ΔP max . For each CM point, a corresponding point along SF zone  112  temporarily appears along zone  112  as color X. These changed-color points form print area  118 . 
     If the impact&#39;s effects are assessed along SF zone  112 , each changed-color point along zone  112  is usually the same as the corresponding CM point. Print area  118  is smaller than OC area  116  because a band  120  not containing any CM point lies between the perimeters of areas  116  and  118 . Perimeter band  120  appears as color A as indicated in  FIGS. 5 b  and 5 c   . If the impact&#39;s effects are assessed along the internal plane, each changed-color point along zone  112  is usually located opposite, or nearly opposite, the corresponding CM point. Print area  118  can be smaller or larger than OC area  116  depending on the size of area  116  relative to that of the projection. Print area  118  is usually smaller than OC area  116  when the projection is of the same size as, or smaller than, area  116 . Depending on how well print area  118  outwardly conforms to OC area  116 , area  118  can be partly inside and partly outside area  116  in the projection case. 
     Local TH parameter difference value ΔP hl1  is preferably the same at every point subject to the TH impact criteria. If so, local difference value ΔP thl  is replaced with a fixed global TH value ΔP thg  of parameter difference ΔP. Local TH value ΔP thl  can, however, differ from point to point subject to the TH impact criteria. In that case, the ΔP thl  values for the points subject to the TH impact criteria form a local TH parameter difference function dependent on the location of each point subject to the TH impact criteria. 
     Impact parameter P can be implemented in various ways. In one implementation, parameter P is pressure resulting from object  104  impacting SF zone  112 , specifically OC area  116 . In the following material, normal pressure at any point in VC region  106  means pressure existent at that point when it is not significantly subjected to any effect of the impact. Normal SF pressure along zone  112  means normal external pressure, usually atmospheric pressure nominally 1 atm, along zone  112 . Normal internal pressure at any point inside region  106  means internal pressure existent at that point when it is not significantly subjected to any effect of the impact. Excess pressure at any point of region  106  means pressure in excess of normal pressure at that point. Excess SF pressure along zone  112  then means pressure in excess of normal SF pressure along zone  112 . Excess internal pressure at any point inside region  106  means internal pressure in excess of normal internal pressure at that point. 
     Object  104  exerts force on OC area  116  during the impact. This force is expressible as excess SF pressure across area  116 . The excess SF pressure reaches a maximum value at one or more points inside area  116  and drops largely to zero along its perimeter. With the excess SF pressure across SF zone  112  embodying impact parameter difference ΔP, the TH impact criteria become principal basic excess SF pressure criteria requiring that the excess pressure at a point along zone  112  equal or exceed a local TH value for that point in order for it to be a TH CM point and temporarily appear as color X. Each local TH excess SF pressure value, which can embody local TH parameter difference value ΔP thl  depending on the internal configuration of OI structure  100 , lies between zero and the maximum excess SF pressure value. 
     Reducing the TH values of excess SF pressure causes the size of A-colored perimeter band  120  to be reduced and print area  118  to more closely match OC area  116 . However, this also causes SF zone  112  to be susceptible to undesired color changes due to bodies other than object  104  impacting zone  112  with less force than object  104  usually impacts zone  112 . The TH excess SF pressure values are chosen to be sufficiently low as to make band  120  quite small while limiting the likelihood of such undesired color changes as much as reasonably feasible. 
     The excess SF pressure causes excess internal pressure to be produced inside VC region  106 . The excess internal pressure is localized mostly to material along OC area  116 . Similar to the excess SF pressure, the excess internal pressure along the projection of area  116  onto the internal plane reaches a maximum value at one or more points inside the projection and drops largely to zero along its perimeter. The excess internal pressure along the internal plane can embody impact parameter difference ΔP. The TH impact criteria along the internal plane become principal basic excess internal pressure criteria requiring that the excess internal pressure at a point along the internal plane equal or exceed a local TH value for that point in order for the corresponding point along SF zone  112  to temporarily appear as color X. Each local TH excess internal pressure value, which can embody local TH parameter difference value ΔP thl , lies between zero and the maximum excess internal pressure value. 
     The impact usually causes VC region  106  to significantly deform along OC area  116 . If so, impact parameter P can be a measure of the deformation. For this purpose, item  122  in  FIG. 5 b    or  5   c  indicates the ID area where the impact causes SF zone  112  to deform. Area  122 , termed the principal SF deformation area, outwardly conforms to OC area  116  and encompasses at least part of, usually most of, area  116 . “DF” hereafter means deformation. Although ID SF DF area  122  is sometimes slightly smaller than OC area  116 , area  116  is also labeled as area  122  in  FIGS. 5 b  and 5 c    and in later drawings to simplify the representation. Item  124  in  FIG. 5 b    or  5   c  indicates the total ID area where object  104  contacts surface  102  and, as shown in  FIG. 5 c   , can extend into FC SF zone  114 . 
     The deformation reaches a maximum value at one or more points inside SF DF area  122  and drops largely to zero along its perimeter. With the deformation along SF zone  112  embodying impact parameter difference ΔP, the TH impact criteria become principal basic SF DF criteria requiring that the deformation at a point along zone  112  equal or exceed a local TH value for that point in order for it to temporarily appear as color X. Each local TH SF DF value lies between zero and the maximum SF DF value. Inasmuch as reducing the TH SF DF values for causing print area  118  to more closely match OC area  116  also causes zone  112  to be susceptible to undesired color changes due to bodies other than object  104  impacting zone  112  with less force than object  104  usually impacts zone  112 , the TH SF DF values are chosen to be sufficiently low as to achieve good matching between areas  116  and  118  while limiting the likelihood of such undesired color changes as much as reasonably feasible. 
     The deformation along SF zone  112  may go into a vibrating mode in which the IDVC portion contracts and expands at an amplitude that rapidly dies out. Such vibrational deformation may sometimes be needed for the IDVC portion to temporarily appear as color X. If vibrational deformation occurs, the associated range of frequencies arising from the impact can be incorporated into the principal SF DF criteria to further reduce the likelihood of undesired color changes. 
     Local TH value ΔP thl  of impact parameter difference ΔP has been described above as essentially a fixed value so that the color along the perimeter of print area  118  changes abruptly from color A to color X in moving from outside area  118  to inside it. However, the temporary color change along the perimeter of area  118  often occurs in a narrow transition band (not shown) which extends along the perimeter of area  118  and in which the color progressively changes from color A to color X in crossing from outside the perimeter transition band to inside it. This arises because the transition from color A to color X largely starts to occur as parameter difference ΔP passes a low local TH value ΔP thll  for each point subject to the TH impact criteria and largely completes the color change as difference ΔP passes, for that point, a high local TH value ΔP thlh  greater than low value ΔP thll . Local TH value ΔP thl  for each point subject to the TH impact criteria is typically that point&#39;s high TH value ΔP thlh  but can be a value between, e.g., halfway between, that point&#39;s TH values ΔP thll  and ΔP thlh . For implementations of difference ΔP with excess pressure or deformation, the transition from color A to color X largely starts to occur as excess pressure or deformation passes a low local TH excess pressure or DF value for each point subject to the TH impact criteria and largely completes the color change as excess pressure or deformation passes a high local TH excess pressure or DF value for that point. 
     OI structure  100  is usually arranged and operated so that generic changed color X is capable of being only a single (actual) color. However, the principal basic TH impact criteria can consist of multiple sets of fully different, i.e., nonoverlapping, principal basic TH impact criteria respectively corresponding to multiple specific (or specified) changed colors materially different from principal color A. More than one, typically all, of the specific changed colors differ, usually materially. The impact on OC area  116  of SF zone  112  is potentially capable of meeting (or satisfying) any of the principal basic TH impact criteria sets. If the impact meets the basic TH impact criteria, generic changed color X is the specific changed color for the basic TH impact criteria set actually met by the impact sometimes dependent on other criteria also being met. The basic TH impact criteria sets usually form a continuous chain in which consecutive criteria sets meet each other without overlapping. 
     The basic TH impact criteria sets can sometimes be mathematically described as follows in terms of impact parameter difference ΔP. Letting n be an integer greater than 1, n principal basic TH impact criteria sets S 1 , S 2 , . . . S n  are respectively associated with n specific changed colors X 1 , X 2 , . . . X n  materially different from principal color A and with n progressively increasing local TH parameter difference values ΔP thl,1 , ΔP thl,2 , . . . ΔP thl,n  lying between zero and maximum parameter difference ΔP max . Each local TH parameter difference value ΔP thl,i , except lowest-numbered value ΔP thl,1 , thereby exceeds next-lowest-numbered value ΔP thl,i−1  where integer i varies from 1 to n. 
     Each basic TH impact criteria set S i , except highest-numbered criteria set S n , is defined by the requirement that parameter difference ΔP equal or exceed local TH parameter difference value ΔP thl,i  but be no greater than an infinitesimal amount below a higher local parameter difference value ΔP thh,i  less than or equal to next higher local TH parameter difference value ΔP thl,i+1 . Each criteria set S i , except set S n , is a ΔP range R i  extending between a low limit equal to TH difference value ΔP thl,i  and a high limit an infinitesimal amount below high difference value ΔP thh,i . Highest-numbered criteria set S n  is defined by the requirement that difference ΔP equal or exceed local TH parameter difference value ΔP thl,n  but not exceed a higher local parameter difference value ΔP thh,n  less than or equal to maximum parameter difference ΔP max . Hence, highest-numbered set S n  is a ΔP range R n  extending between a low limit equal to TH difference value ΔP thl,n  and a high limit equal to high difference value ΔP thh,n . 
     High-limit difference value ΔP thh,i  for each range R i , except highest range R n , usually equals low-limit difference value ΔP thl,i+1  for next higher range R n+1 , and high-limit difference value ΔP thh,n  for highest range R n  usually equals maximum difference ΔP max . In that case, criteria sets S 1 -S n  substantially fully cover a total ΔP range extending continuously from lowest difference value ΔP thl,1 , to maximum difference ΔP max . Impact parameter difference ΔP c potentially capable of meeting any of criteria sets S 1 -S n . If the impact meets the TH impact criteria so that difference ΔP meets the TH impact criteria, changed color X is specific changed color X i  for criteria set S i  actually met by difference ΔP. Should each local TH difference value ΔP thl,i  be the same at every point subject to the TH impact criteria, each local TH difference value ΔP thl,1  is replaced with a fixed global TH value ΔP thg,i  of difference ΔP. 
     The TH impact criteria sets can, for example, consist of fully different ranges of excess SF pressure across OC area  116  or excess internal pressure along the projection of area  116  onto the internal plane. Each range of excess SF or internal pressure is associated with a different one of the specific changed colors. Changed color X is then specific changed color X i  for the range of excess SF or internal pressure met by the impact. The low limit of each pressure range is the minimum value of excess SF or internal pressure for causing color X to be specific changed color X i  for that pressure range. The high limit of each pressure range, except the highest pressure range, is preferably an infinitesimal amount below the low limit of the next highest range so that the TH impact criteria sets occupy a continuous total pressure range beginning at the low limit of the lowest range. All the specific changed colors X 1 -X n  preferably differ materially from one another. 
     Use of TH impact criteria sets provides a capability to distinguish between certain different types of impacts. For instance, if the maximum excess SF pressure usually exerted by one embodiment of object  104  exceeds the minimum excess SF pressure usually exerted by another embodiment of object  104 , appropriate choice of the TH impact criteria sets enables OI structure  100  to distinguish between impacts of the two object embodiments. In tennis, suitable choice of the TH impact criteria sets enables structure  100  to distinguish between impacts of a tennis ball and impacts of other bodies which usually impact SF zone  112  harder or softer than a tennis ball. Color X is generally dealt with below as a single color even though it can be provided as one of multiple changed colors dependent on the TH impact criteria sets. 
     The change, or switch, from color A to color X along print area  118  places VC region  106  in a state, termed the “changed” state, in which X light temporarily leaves the IDVC portion along area  118 . In the changed state, region  106  continues to appear as color A along the remainder of SF zone  112  except possibly at any location where another temporary change to color X occurs during the current temporary color change due to object  104  also impacting zone  112  so as to meet the TH impact criteria. The IDVC portion later returns to appearing as color A. If another change to color X occurs during the current temporary color change at any location along zone  112  due to another impact, any other such location along zone  112  likewise later returns to appearing as color A. Region  106  later returns to appearing as color A along all of zone  112  so as to return, or switch back, to the normal state. The impacts can be by the same or different embodiments of object  104 . 
     An occurrence of the changed state herein means only the temporary color change due to the impact causing that changed-state occurrence. If, during a changed-state occurrence, object  104  of the same or a different embodiment again impacts SF zone  112  sufficient to meet the TH impact criteria, any temporary color change which that further impact causes along zone  112  during the current changed-state occurrence constitutes another changed-state occurrence. Multiple changed-state occurrences can thus overlap in time. Print area  118  of one of multiple time-overlapping changed-state occurrences can also overlap with area  118  of at least one other one of those changed-state occurrences. The situation of multiple time-overlapping changed-state occurrences is not expressly mentioned further below in order to shorten this description. However, any recitation below specifying that a VC region, such as VC region  106 , returns to the normal state after the changed state means that, if there are multiple time-overlapping changed-state occurrences, the VC region returns to the normal state after the last of those occurrences without (fully) returning to the normal state directly after any earlier one of those occurrences. 
     VC region  106  is in the changed state for a CC duration (or time period) Δt dr  generally defined as the interval from the time at which print area  118  first fully appears as changed color X to the time at which area  118  starts returning to color A, i.e., the interval during which area  118  temporarily appears as color X. CC duration Δt dr  is usually at least 2 s in order to allow persons using OI structure  100  sufficient time to clearly determine that area  118  exists and where it exists along SF zone  112 . Duration Δt dr  is often at least 4 s, sometimes at least 6 s, and is usually no more than 60 s but can be 120 s or more. 
     In particular, the Δt dr  length depends considerably on the type of activity for which OI structure  100  is being used. If the activity is a ball-based sport such as tennis, basketball, volleyball, or baseball/softball, CC duration Δt dr  is desirably long enough for players and observers, including any sports official(s), to clearly determine the location of print area  118  on SF zone  112  but not so long as to significantly interrupt play. The Δt dr  length for such a sport is usually at least 2, 4, 6, 8, 10, or 12 s, can be at least 15, 20, or 30 s, and is usually no more than 60 s but can be longer, e.g., up to 90 or 120 s or more, or shorter, e.g., no more than 30, 20, 15, 10, 8, or 6 s. For such a ball-based sport in which the ball embodying object  104  bounces off surface  102 , duration Δt dr  is usually much longer than the time duration (or contact time) Δt oc , almost always less than 25 ms, during which the ball contacts zone  112  during the impact. 
     CC duration Δt dr  may be at an automatic (or natural) value Δt drau  that includes a base portion Δt drbs  passively determined by the (physical/chemical) properties of the material(s) in the ISCC structure. Base duration Δt drbs  is fixed (constant) for a given set of environmental conditions, including a given external temperature and a given external pressure, nominally 1 atm, at identical impact conditions. VC region  106  may contain componentry, described below, which automatically extends duration Δt dr  by an amount Δt drext  beyond base duration Δt drbs . Automatic duration value Δt drau  consists of base duration Δt drbs  and potentially extension duration Δt drext . Automatic value Δt drau  is usually at least 2 s, often at least 4 s, sometimes at least 6 s, and usually no more than 60 s, often no more than 30 s, sometimes no more than 15 s. Absent externally caused adjustment, the changed state automatically terminates at the end of value Δt drau . 
     Automatic duration value Δt drau  is usually in a principal pre-established CC time duration range, i.e., an impact-to-impact Δt dr  range established prior to impact. The length of the pre-established CC duration range, i.e., the time period between its low and high ends from impact to impact, is relatively small, usually no more than 2 s, preferably no more than 1 s, more preferably no more than 0.5 s, so that the impact-to-impact variation in automatic value Δt drau  is quite small. 
     The appearance of VC region  106  as color A during the normal state occurs while OI structure  100  is in operation. The production of color A during structure operation often occurs passively, i.e., only by light reflection. Region  106  thus appears as color A when structure  100  is inactive. However, color A can be produced actively, e.g., by an action involving light emission from region  106 . If so, the light emission is usually terminated to save power when structure  100  is inactive. In that case, region  106  appears as another color, termed passive color P, along SF zone  112  while structure  100  is inactive. Passive color P, which can be the same as secondary color A′, necessarily differs from color A and usually from color X. 
       FIG. 5 b    presents an example in which object  104  contacts surface  102  fully within SF zone  112 . Total ID OC area  124  here is the same as OC area  116 . Print area  118  encompasses most of, and fully conforms to, OC area  116  so that areas  116  and  118  are largely concentric. Hence, print area  118  fully outwardly conforms to OC area  116 .  FIG. 22 a    below presents an example, similar to that of  FIG. 5 b   , in which print area  118  fully outwardly conforms to OC area  116  and does not fully inwardly conform to area  116 . 
       FIG. 5 c    presents an example in which object  104  contacts surface  102  within both of SF zones  112  and  114  in the same impact. Total OC area  124  here consists of OC area  116  and an adjoining secondary ID OC area  126  of zone  114 . The impact on secondary ID OC area  126  does not cause it to change color significantly. Hence, area  126  largely remains secondary color A′. Print area  118  at least partly encompasses OC area  116  and may, or may not, encompass most of it depending on the sizes of OC areas  116  and  126  and perimeter band  120  relative to one another. Print area  118  fully outwardly conforms to OC area  116  so as to be largely concentric with it.  FIG. 22 b    below presents an example, similar to that of  FIG. 5 c   , in which print area  118  outwardly conforms mostly, but not fully, to OC area  116  and does not inwardly conform mostly to it. 
     The impact on both of OC areas  116  and  126  is sometimes insufficient to meet the principal TH impact criteria for principal area  116  even though the TH impact criteria would be met if total OC area  124  were in SF zone  112 . If so, area  116  may continue to appear as color A. Alternatively, FC region  108  contains impact-sensitive material extending along interface  110  to a distance approximately equal to the maximum lateral dimension of print area  118  during impacts. Although secondary OC area  126  remains color A′ after the impact, the combination of the impact-sensitive material in region  108  and the ISCC material in VC region  106  causes print area  118  to temporarily appear as color X if the impact meets composite basic TH impact criteria usually numerically the same as the principal basic TH impact criteria. 
       FIGS. 6 a -6 c , 11 a -11 c , 12 a -12 c , 13 a -13 c , 14 a -14 c , 15 a   - 15   c ,  16   a - 16   c ,  17   a - 17   c ,  18   a - 18   c , and  19   a - 19   c  present side cross sections of ten embodiments of OI structure  100  where each triad of Figs. ja-jc for integer j being 6 and then varying from 11 to 19 depicts a different embodiment. The basic side cross sections, and thus how the embodiments appear in the normal state, are respectively shown in  FIGS. 6 a , 11 a   ,  12   a ,  13   a ,  14   a ,  15   a ,  16   a ,  17   a ,  18   a , and  19   a  corresponding to  FIG. 5 a   .  FIGS. 6 b , 11 b , 12 b , 13 b , 14 b , 15 b , 16 b , 17 b , 18 b , and 19 b    corresponding to  FIG. 5 b    present examples of changes that occur during the changed state when object  104  impacts fully within SF zone  112 .  FIGS. 6 c , 11 c , 12 c , 13 c , 14 c , 15 c , 16 c , 17 c , 18 c , and 19 c    present examples of changes that occur during the changed state when object  104  simultaneously impacts both of SF zones  112  and  114 . 
     Referring to  FIGS. 6 a -6 c    (collectively “ FIG. 6 ”), they illustrate a general embodiment  130  of OI structure  100  for which duration Δt dr  of the changed state is automatic value Δt drau  absent externally caused adjustment. VC region  106  here consists only of the ISCC structure indicated here and later as item  132 . In  FIG. 6 , surface  102  is flat and extends parallel to a plane generally tangent to Earth&#39;s surface. However, surface  102  can be significantly curved. Even when surface  102  is flat, it can extend at a significant angle to a plane generally tangent to Earth&#39;s surface as exemplified below in  FIGS. 102 a  and 102 b   . Interface  110  between color regions  106  and  108  extends perpendicular to surface  102 . See  FIG. 6 a   . Interface  110  can be a flat surface or a curved surface which appears straight along a plane extending through regions  106  and  108  perpendicular to surface  102 . Regions  106  and  108  lie on a substructure (or substrate)  134  usually consisting of insulating material at least where they meet substructure  134  along a flat region-substructure interface  136  extending parallel to surface  102 . 
     Largely no light is usually transmitted or emitted by substructure  134  so as to cross interface  136  and exit VC region  106  via SF zone  112 . Nor does largely any light usually enter region  106  along interface  110  or any other side surface of region  106  so as to exit it via zone  112 . In short, light usually enters region  106  only along zone  112 . Changes in the visual appearance of region  106  largely depend only on (a) incident light reflected by region  106  so as to exit it via zone  112 , (b) any light emitted by region  106  and exiting it via zone  112 , and (c) any light entering region  106  along zone  112 , passing through region  106 , reflected by substructure  134 , passing back through region  106 , and exiting it along zone  112 . 
     Light (if any) reflected by substructure  134  so as to leave it along VC region  106  during the normal state is termed ARsb light. Preferably, no ARsb light is present. All light striking SF zone  112  is preferably absorbed by region  106  or/and reflected by it so as to leave it via zone  112 , interface  110 , or another such side surface. Region  106 , potentially in combination with FC region  108 , may be manufactured as a separate unit and later installed on substructure  134 . If so, absence of ARsb light enables the color characteristics, including CC characteristics, of region  106  to be independent of the color characteristics of substructure  134 . 
     Light, termed ADic light, normally leaving ISCC structure  132  via SF zone  112  after being reflected or/and emitted by structure  132 , and thus excluding any substructure-reflected ARsb light, consists of (a) light, termed ARic light, normally reflected by structure  132  so as to leave it via zone  112  after striking zone  112  and (b) light (if any), termed AEic light, normally emitted by structure  132  so as to leave it via zone  112 . Reflected ARic light is invariably always present. Emitted AEic light may or may not be present. A substantial part of any ARsb light passes through structure  132 . ARic light, any AEic light, and any ARsb light normally leaving structure  132 , and thus VC region  106 , via zone  112  form A light. Region  106  thereby normally appears as color A. Each of ADic light and either ARic or AEic light is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of A light. 
     Referring to  FIGS. 6 b  and 6 c   , item  138  is the IDVC portion of VC region  106 , i.e., the changed portion which appears along print area  118  as color X during the changed state. Area  118  is then the upper surface of IDVC portion  138 , basically a cylinder whose cross-sectional area is that of area  118 . The lateral boundary of portion  138  extends perpendicular to SF zone  112 . Object  104  in  FIGS. 6 b  and 6 c    appears above surface  102  at locations corresponding respectively to those in  FIGS. 5 b  and 5 c    and therefore at locations subsequent to impacting OC area  116 . 
     Print area  118  is shown in  FIGS. 6 b  and 6 c    and in analogous later side cross-sectional drawings with extra thick line to clearly identify the print-area location along SF zone  112 . IDVC portion  138  is laterally demarcated in  FIG. 6 b    and in analogous later side cross-sectional drawings with dotted lines because its location in VC region  106  depends on where object  104  contacts zone  112 . Portion  138  is laterally demarcated in  FIG. 6 c    and in analogous later side cross-sectional drawings with a dotted line and the solid line of interface  110  because portion  138  terminates along interface  110  in those drawings. Item  142  in  FIGS. 6 b  and 6 c    is the principal ID segment of ISCC structure  132  in portion  138  and is identical to it here. However, ID ISCC segment  142  is a part of portion  138  in later embodiments of OI structure  100  where region  106  contains structure besides ISCC structure  132 . 
     Light (if any) reflected by substructure  134  so as to leave it along IDVC portion  138  during the changed state is termed XRsb light. XRsb light can be the same as, or significantly differ from, ARsb light depending on how the light processing in portion  138  during the changed state differs from the light processing in VC region  106  during the normal state. XRsb light is absent when ARsb light is absent. 
     Light, termed XDic light, temporarily leaving ISCC segment  142  via print area  118  after being reflected or/and emitted by segment  142 , and thus excluding any substructure-reflected XRsb light, consists of (a) light, termed XRic light, temporarily reflected by segment  142  so as to leave it via area  118  after striking area  118  and (b) light (if any), termed XEic light, temporarily emitted by segment  142  so as to leave it via area  118 . Reflected XRic light is invariably always present. Emitted XEic light may or may not be present. XDic light differs materially from A and ADic light. A substantial part of any XRsb light passes through segment  142 . XRic light, any XEic light, and any XRsb light temporarily leaving segment  142 , and thus IDVC portion  138 , via area  118  form X light so that portion  138  temporarily appears as color X. Each of XDic light and either XRic or XEic light is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of X light. 
     Timing and Color-Difference Parameters 
     VC region  106  of OI structure  130  starts the forward transition from the normal state to the changed state before or after object  104  leaves SF zone  112  depending on the length of duration Δt oc  during which object  104  contacts OC area  116 . Region  106  can even enter the changed state before object  104  leaves zone  112 . However, a person cannot generally see print area  118  until object  104  leaves zone  112 . One important timing parameter is thus the full forward transition delay (response time) Δt f , if any, extending from the instant, termed object-separation time t os , at which object  104  just fully separates from area  116  to the instant, termed approximate forward transition end time t fe , at which region  106  approximately completes the forward transition and IDVC portion  138  approximately first appears as changed color X. “OS” and “XN” hereafter respectively mean object-separation and transition. Determination of full forward XN delay Δt f  is complex because it depends on changes in spectral radiosity Jλ and thus on wavelength changes rather than on changes in radiosity J itself. 
     Another important timing parameter is the immediately following time duration Δt dr , discussed above, in which VC region  106  is in the changed state. CC duration Δt dr  extends from forward XN end time t fe  to the instant, termed approximate return XN start time t rs , at which region  106  approximately starts the return transition from the changed state back to the normal state and IDVC portion  138  approximately starts changing from appearing as color X to returning to appear as color A. Although usually less important than forward XN delay Δt f , a final important timing parameter is the full return XN delay (relaxation time) Δt r  extending from approximate return XN start time t rs  to the instant, termed approximate return XN end time t re , at which region  106  approximately completes the return transition and portion  138  approximately first returns to appearing as color A. 
     The spectral radiosity constituency, i.e., the variation of spectral radiosity Jλ with wavelength A, for a color consists of one or wavelength bands in the visible light spectrum. Each wavelength band may reach one or more peak values of spectral radiosity depending on what is considered to be a wavelength band. Referring to  FIG. 7 , it illustrates an exemplary spectral radiosity constituency  150  for color light such as A or X light where J λh  is the top of the illustrated J λ  range. In this example, J λ  constituency  150  may be viewed as consisting of three wavelength bands or two wavelength bands with the right-most band having two peaks. In any event, the wavelengths encompassed by constituency  150  lie between the low end λ l  and high end λ h  of the visible spectrum where low-end wavelength λ l  is nominally 380-400 nm and high-end wavelength λ h  is nominally 700-780 nm. For a spectral color, constituency  150  degenerates into a single vertical line at the wavelength of that color. 
       FIG. 8  shows how an exemplary spectral radiosity constituency  152 , two bands, for A light changes with time into an exemplary spectral radiosity constituency  154 , one band, for X light during the forward transition from the normal state to the changed state. The top portion of  FIG. 8  illustrates the appearance of color-A J λ  constituency  152  at a time t p  during the normal state and thus prior to the forward transition. Although color-X J λ  constituency  154  does not exist at pre-transition time t p , thick-line item  154   p  along the wavelength axis in the top portion of  FIG. 8  indicates the expected wavelength extent of color-X constituency  154 . 
     The middle portion of  FIG. 8  depicts an exemplary intermediate spectral radiosity constituency  156  at a time t m  during the forward transition. Intermediate J λ  constituency  156  is a combination, largely additive, of a partial version  152   m  of color-A constituency  152  and a partial version  154   m  of-color X constituency  154 . The right-most band of reduced color-A J λ  constituency  152   m  combined with the dashed line extending from that band to the right indicates how it would appear if color A were being converted into black. Partial color-X J λ  constituency  154   m  combined with the dashed line extending from constituency  154   m  to the left indicates how constituency  154   m  would appear if color X were being converted from black. The bottom portion of  FIG. 8  illustrates the appearance of color-X constituency  154  at a time t c  during the changed state and thus after the forward transition. Although color-A constituency  152  does not exist at post-transition time t c , the two parts of thick-line item  1520  along the wavelength axis in the bottom portion of  FIG. 8  indicate the exemplary wavelength extent of constituency  152 . 
     Forward XN delay Δt f  can be determined by changes in various spectral radiosity parameters as a function of time. Using spectral radiosity J λ  itself, forward delay Δt f  is the time for spectral radiosity J λ  to decrease from (i) a high value J λfh  equal to or slightly less than the magnitude ΔJ λmax  of the difference between the maximum J λ  values for the color-A and color-X J λ  constituencies at a wavelength present in one or both of them, i.e., at any wavelength for which spectral radiosity J λ  is greater than zero in at least one of the color A and color-X J λ  constituencies, to (ii) a low value J λfl  equal or slightly greater than zero. 
     This Δt f  determination technique is most easily applied at a wavelength present in one of the color-A and color-X J λ  constituencies but not in the other. Due to noise in experimental J λ  data, the accuracy of the Δt f  determination is usually increased by choosing a wavelength at which spectral radiosity J λ  reaches a peak value. Dotted lines  158  and  160  in each of the three portions of  FIG. 8  indicate such wavelengths for J λ  constituencies  152  and  154 . J λ  maximum difference magnitude ΔJ λmax  is then simply the maximum J λ  value for color-A J λ  constituency  152  along dotted line  158  in the top portion of  FIG. 8  or the maximum J λ  value for color-X J λ  constituency  154  along dotted line  160  in the bottom portion of  FIG. 8 . The length of line  158  or  160  represents difference magnitude ΔJ λmax . 
     Spectral radiosity J λ  can nonetheless be used to determine forward XN delay Δt f  at a wavelength, indicated by dotted line  162  in each of the three portions of  FIG. 8 , common to both the color-A and color-X J λ  constituencies. The length of dotted line  162  represents difference magnitude ΔJ λmax . As examination of  FIG. 8  indicates, difference magnitude ΔJ max  for the common-wavelength situation is usually less than magnitude ΔJ max  when the color-A J λ  constituency has a wavelength not in the color-X J λ  constituency and vice versa. 
     High value J λfh  and low value J λfl  are respectively slightly less than difference magnitude ΔJ λmax  and slightly greater than zero if OS time t os  occurs after the instant, termed actual forward XN start time t f0 , at which VC region  106  actually starts the forward transition to the changed state and IDVC portion  138  actually starts changing to appear as color X or/and if forward XN end time t fe  occurs before the instant, termed actual forward XN end time t f100 , at which region  106  actually completes the forward transition to the changed state and portion  138  actually first appears as color X. In particular, high value J λfh  equals difference magnitude ΔJ λmax  minus (a) an amount, usually small, corresponding to the difference between times t os  and t f0  if OS time t os  occurs after actual forward XN start time t f0  and (b) an amount, usually small, corresponding to the difference between times t f100  and t fe  if actual forward XN end time t f100  ends, as usually occurs, after approximate forward XN end time t fe . Value J λfh  otherwise equals magnitude ΔJ λmax . 
     Low value J λfl  similarly equals (a) an amount, usually small, corresponding to the difference between times t os  and t f0  if OS time t os  occurs after actual forward XN start time t f0  and (b) an amount, usually small, corresponding to the difference between times t f100  and t fe  if actual forward XN end time t f100  ends after approximate forward XN end time t fe . Value J λfl  otherwise is zero. The modifications to values J λfh  and J λfl  may be so small as to not significantly affect the Δt f  determination and, if so, need not be performed. If actual forward XN start time t f0  occurs after OS time t os , the difference between times t f0  and t os  should be added to the JA-determined value to obtain actual forward delay Δt f . This modification may likewise be so small as to not significantly affect the Δt f  determination and, if so, need not be performed. Forward XN delay Δt f  can also be determined as an average of the summation of Δt f  values determined at two or more suitable wavelengths using this Δt f  determination technique. 
     Another spectral radiosity parameter suitable for use in determining forward XN delay Δt f  is the spectrum-integrated absolute spectral radiosity difference ΔJ AM , basically an integrated version of the spectral radiosity summation Δt f  technique. Let J λA (λ) and J λX (λ) respectively represent the spectral radiosities for A and X light as a function of wavelength A for which J λ  constituencies  152  and  154  are respective examples. Let J AM (λ) represent the spectral radiosity for light of wavelength of a variable color, termed variable color M, as a function of wavelength A such that IDVC portion  138  appears along print area  118  as color M. Each J λ  constituency  152 ,  154 , or  156  is an example of color-M spectral radiosity J λM (λ). Spectrum-integrated absolute spectral radiosity difference ΔJ AM , often simply radiosity difference ΔJ AM , is given by the integral:
 
Δ J   AM =∫ VS   |J   λA (λ)− J   λM (λ)| dλ   (A1)
 
where VS indicates that the integration is performed across the visible spectrum.
 
     An understanding of radiosity difference ΔJ AM  is facilitated with the assistance of  FIG. 9  which, similar to  FIG. 8 , illustrates how example  152  of color-A spectral radiosity J λA (λ) changes into example  154  of color-X spectral radiosity J λX (λ) during the forward transition. Example  152  of color-A spectral radiosity J λA (λ) occurs at time t p  during the normal state as represented in the top portion of  FIG. 9  and is repeated in the middle and bottom portions of  FIG. 9  in dotted form because spectral radiosity J λA (λ) appears in the integrand |J λA (λ)−J λM (λ)| of radiosity difference ΔJ AM . At time t p , variable color M is color A so that color M-spectral radiosity J λM (λ) equals color A-spectral radiosity J λA (λ). Radiosity difference ΔJ AM  is zero at time t p . 
     Variable color M is an intermediate color between colors A and X at time t m  during the forward transition. Color-M spectral radiosity J λM (λ) then has a wavelength variation between the wavelength variations of spectral radiosities J λA (λ) and J λ  (λ). Radiosity difference ΔJ AM  at time t m  is thus at some finite value represented by slanted-line area  164  between color-A J λ  constituency  152  and intermediate J λ  constituency  156  in  FIG. 9 . At time t c  during the changed state, variable color M is color X so that color-M spectral radiosity J λM (λ) equals color-X spectral radiosity J λX (λ). Radiosity difference ΔJ AM  at time t c  is also at some finite value represented by slanted-line area  166  between color-A constituency  152  and color-X J λ  constituency  154  in  FIG. 9 . The value of radiosity difference ΔJ AM  at time t c  is usually a maximum. The variation of radiosity difference ΔJ AM  with time thereby characterizes the forward transition. 
     Let ΔJ AX  represent the spectrum-integrated absolute spectral radiosity difference ∫ VS |J λA (λ)−J λX (λ)|dλ between A and X light. Using radiosity difference ΔJ AM , forward XN delay Δt f  is the time period for radiosity difference ΔJ AM  to change from a low value equal or slightly greater than zero to a high value equal to or slightly less than ΔJ AX . If OS time t os  occurs after actual forward XN start time t f0 , the low ΔJ AM  value is an amount corresponding to the difference between times t os  and t f0 . The low ΔJ AM  value can often be taken as zero without significantly affecting the Δt f  determination. If actual forward XN start time t f0  occurs after OS time t os , the difference between times t f0  and t os  should be added to the JA-determined Δt f  value to obtain actual forward delay Δt f . This modification is sometimes so small as to not significantly affect the Δt f  determination and, if so, need not be performed. For the usual situation in which approximate forward XN end time t fe  occurs before actual forward XN end time t f100 , the high ΔJ AM  value equals ΔJ λ  X minus an amount corresponding to the difference between times t f100  and t fe . The high ΔJ AM  value can often be taken as ΔJ λ  x without significantly affecting the Δt f  determination. 
       FIG. 10  depicts how a general spectral radiosity parameter J p  varies with time t during a full operational cycle in which VC region  106  goes from the normal state to the changed state and then back to the normal state. General radiosity parameter J p  can be spectral radiosity J λ  or spectrum-integrated absolute spectral radiosity difference ΔJ AM . Radiosity parameter J p  varies between zero and a maximum value J pmax  formed with difference ΔJ λmax  or the high ΔJ AM  value when parameter J p  is spectral radiosity J λ  or radiosity difference ΔJ AM . Curve  168  represents the J p  variation with time t. 
     In addition to times mentioned above, the following times appear along the time axis in  FIG. 10 : time t ip  at which object  104  impacts OC area  116 , approximate forward XN start time t fs  at which VC region  106  approximately starts the forward transition from the normal state to the changed state and IDVC portion  138  approximately starts changing from appearing as color A to appearing as color X, 10%, 50%, and 90% forward XN times trio, t f50 , and t f90  at which portion  138  has respectively changed 10%, 50%, and 90% from actually appearing as color A to actually appearing as color X during the forward transition, actual return XN start time t r0  at which region  106  actually starts the return transition back to the normal state and portion  138  actually starts changing from appearing as color X to returning to appear as color A, 10%, 50%, and 90% return XN times trio, t r50 , and t r90  at which region  106  has respectively changed 10%, 50%, and 90% from actually appearing as color X to actually appearing as color A during the return transition, actual return XN end time t r100  at which region  106  actually completes the return transition and portion  138  actually first returns to appearing as color A, and time t p   +  during the normal state following the return transition. 
     Using radiosity parameter J p , 10%, 50%, and 90% forward XN times t f10 , t f50 , and t f90  are instants at which parameter J p  actually respectively reaches 10%, 50%, and 90% of maximum value J pmax  during the forward transition. 10%, 50%, and 90% return XN times trio, t r50 , and t r90  are instants at which parameter J p  actually has respectively decreased 10%, 50%, and 90% below value J pmax  during the return transition. Item Δt f50  is the 50% forward XN time delay from OS time t os  to 50% forward XN time t f50  during the forward transition. Item Δt f90  is the 90% forward XN time delay from time t os  to 90% forward XN time t f90  during the forward transition. Item Δt f10-90  is the 10%-to-90% forward XN time delay from 10% forward XN time t f10  to time t f90  during the forward transition. Item Δt r50  is the 50% return XN time delay from approximate return XN start time t rs  to 50% return XN time t r50  during the return transition. Item Δt r90  is the 90% return XN time delay from time t rs  to 90% return XN time t r90  during the return transition. Item Δt r10-90  is the 10%-to-90% return XN time delay from 10% return XN time trio to time t r90  during the return transition. 
     Percentage times t f10 , t f50 , t f90 , t r10 , t r50 , and t r90  can usually be ascertained relatively precisely because dJ p /dt, the time rate of change of radiosity parameter J p , is relatively high in the vicinities of those six times, especially times t f50  and t r50 . Conversely, times t f0  and t f100  at which the forward transition actually respectively starts and ends are often difficult to determine precisely because rate dJ p /dt is relatively low in their vicinities. Times t r0  and t r100  at which the return transition actually respectively starts and ends are likewise often difficult to determine precisely for the same reason. In view of this, the start and end of the forward transition are respectively approximated by times t fs  and t fe  which are relatively precisely determinable utilizing time t f50 . Similarly, the start and end of the return transition are respectively approximated by times t rs  and t re  which are relatively precisely determinable utilizing time t r50 . 
     In particular, a dotted line  170  having a slope S f  is tangent to curve  168  at point  172  at 50% forward XN time t f50  where radiosity parameter J p  has risen to 50% of value J pmax . Slope S f  equals rate dJ p /dt at time t f50  and can be determined relatively precisely. Time differences t f50 −t fs  and t fe −t f50  each equal (J pmax /2)/S f . Forward XN start time t fs  and forward XN end time t fe  are:
 
 t   fs   =t   f50   −J   pmax /2 S   f   (A2)
 
 t   fe   =t   f50   +J   pmax /2 S   f   (A3)
 
which can be determined relatively precisely because time t f50  can be determined relatively precisely.
 
     Similarly, a dotted line  174  having a slope S r  is tangent to curve  168  at point  176  at 50% return XN time t r50  where parameter J p  has dropped to 50% of value J pmax . Slope S r  equals rate dJ p /dt at time t r50  and can be determined relatively precisely. Time differences t r50 −t rs  and t re −t r50  each equal (J pmax /2)/S r . Return XN start time t rs  and return XN end time t re  are:
 
 t   rs   =t   r50   −J   pmax /2 S   r   (A4)
 
 t   re   =t   r50   +J   pmax /2 S   r   (A5)
 
which can be determined relatively precisely because time t r50  can be determined relatively precisely.
 
     Approximate full forward XN delay Δt f  is usually no more than 2 s, preferably no more than 1 s, more preferably no more than 0.5 s, even more preferably no more than 0.25 s. 50% forward XN delay Δt f50  is usually no more than 1 s, preferably no more than 0.5 s, more preferably no more than 0.25 s, even more preferably no more than 0.125 s. 90% forward XN delay Δt f90  is usually less than 2 s, preferably less than 1 s, more preferably less than 0.5 s, even more preferably less than 0.25 s. The same applies to 10%-to-90% forward XN delay Δt f10-90 . 
     The maximum values for full return XN delay Δt r , 10% return XN delay Δt r10 , 50% return XN delay Δt r50 , and 90% return XN delay Δt r90  fall into (a) a short-delay category in which they are relatively short to avoid impeding the activity in which object  104  is being used and (b) a long-delay category in which they can be relatively long without significantly impeding that activity and in which their greater lengths can sometimes lead to reduction in the cost of manufacturing OI structure  130 . For the short-delay category, return XN delays Δt r , Δt r10 , Δt r50 , and Δt r90  have the same usual and preferred maximum values respectively as forward XN delays Δt f , Δt f10 , Δt f50 , and Δt f90 . Return XN delays Δt r , Δt r10 , Δt r50 , and Δt r90  have the following maximum values for the long-delay category. Delay Δt r  is usually no more than 10 s, preferably no more than 5 s. Delay Δt r50  is usually no more than 5 s, preferably no more than 2.5 s. Delay Δt r90  is usually less than 10 s, preferably less than 5 s. The same applies to delay Δt f10-90 . 
     CC duration Δt dr , the difference between return XN start time t rs  and forward XN end time t fe , is: 
                           Δ   ⁢           ⁢     t   dr       =       ⁢         t   rs     -     t   fe       =       (       t     r   ⁢           ⁢   50       -       J   pmax       2   ⁢     S   r           )     -     (       t     f   ⁢           ⁢   50       -       J   pmax       2   ⁢     S   f           )                     =       ⁢       t     r   ⁢           ⁢   50       -     t     f   ⁢           ⁢   50       +       (       J   pmax     2     )     ⁢           ⁢     (       1     S   f       -     1     S   r         )                       (   A6   )               
which likewise can be determined relatively precisely because times t f50  and t r50  can both be determined relatively precisely.
 
       FIG. 10  depicts the preferred situation in which OS time t os  occurs after actual forward XN start time t f0 . Forward XN start time t f0  can, however, occur after OS time t os . If so, between times t os  and t f0 , there is a delay in which radiosity parameter J p  is zero.  FIG. 10  depicts the situation in which approximate forward XN start time t fs  occurs after OS time t os . Forward XN start time t fs  preferably occurs before OS time t os . 
     The actual total time period Δt totact  (not indicated in  FIG. 10 ) from actual forward XN start time t f0  to actual return XN end time t r100  is difficult to determine precisely because times t f0  and t r100  are difficult to determine precisely. Additionally, OS time t os  may as mentioned above occur after forward XN start time t f0 . If so, the short interval between times t f0  and t os  is insignificant practically because object  104  blocks print area  118  from then being visible. Approximate return XN end time t re  is highly representative of when area  118  returns to appearing as principal color A. A useful parameter for dealing with the time period needed to switch from the normal state to the changed state and back to the normal state is the effective total time period Δt toteff  (also not indicated in  FIG. 10 ) from OS time t os  to return XN end time t re . 
     The time period between points in high-level tennis is seldom less than 15 s. If print area  118  generated during a point due to impact of a tennis ball embodying object  104  is desirably not present during the immediately subsequent point, effective total time period Δt toteff  can be chosen to be no more than 15 s. Area  118  caused by a tennis ball during a point will then automatically not be present during the immediately subsequent point in the vast majority of consecutive-point instances. With full forward XN delay Δt f  and full return XN delay Δt r  each being no more than 1 s, automatic value Δt drau  of CC duration Δt dr  is chosen to be close to, but less than, 15 s, e.g., usually at least 10 s, preferably at least 12 s. These Δt drau  values should almost always provide sufficient time to examine area  118  and either immediately determine whether the ball is “in” or “out” or, if possible, extend duration Δt dr  to examine area  118  more closely. 
     Non-lobbed groundstrokes hit by highly skilled tennis players typically take roughly 2 s to travel from one baseline to the other baseline and back to the initial baseline. The presence of two or more print areas  118  created during a point is not expected to be significantly distracting to the players. Also, the likelihood of two such areas  118  at least partly overlapping is very low. Nonetheless, if only one area  118  is desirably present at any time during a point, effective total time period Δt toteff  can be chosen to be approximately 2 s. By arranging for each XN delay Δt f  or Δt r  to be no more than 0.25 s, automatic duration value Δt drau  is at least 1.5 s. This should usually give the players and any associated tennis official(s) enough time to make an immediate in/out determination or, if possible, extend CC duration Δt dr  for more closely examining area  118 . In addition, automatic value Δt drau  can more closely approach 2 s by configuring VC region  106  as described below for  FIGS. 11 a   - 11   c.    
     Two colors differ materially if the standard human eyes/brain can essentially instantaneously clearly distinguish the two colors when one of them rapidly replaces the other or when they appear adjacent to each other. Hence, colors A and X differ materially if the standard human eye/brain can essentially instantaneously identify print area  118  when it changes from principal color A to changed color X. If object  104  simultaneously impacts both VC SF zone  112  and FC SF zone  114  in an embodiment of OI structure  100  where secondary color A′ of zone  114  is the same as color A, colors A and X also differ materially if the standard human eye/brain can essentially instantaneously determine that object  104  has impacted both of zones  112  and  114  due to the difference in color between area  118  and zone  114 . 
     What constitutes a material difference between colors A and X can sometimes be numerically quantified. In this regard, colors A and X occur in the all-color CIE L*a*b* color space in which a color is characterized by a dimensionless lightness L*, a dimensionless green/red hue parameter a*, and a dimensionless blue/yellow hue parameter b*. Lightness L* varies from 0 to 100 where a low number indicates dark and a high number indicates light. L* values of 0 and 100 respectively indicate black and white regardless of the a* and b* values. Hue parameters a* and b* have no numerical limits but typically range from a negative value as low as −128 to a positive value as high as 127. For green/red parameter a*, a negative number indicates green and a positive number indicates red. A negative number for blue/yellow parameter indicates blue while a positive number indicates yellow. Colors of particular hues determined by hue parameters a* and b* become lighter as lightness L* increases so that the colors contain more white and darker as lighter as lightness L* decreases so that they contain more black. 
     Hoffmann, “CIE Lab Color Space”, docs-hoffmann.de/cielab03022003.pdf, 10 Feb. 2013, 63 pp., contents incorporated by reference herein, presents the sRGB and AdobeRGB, subspaces of the CIE L*a*b* color space for L* values of 10, 20, 30, 40, 50, 60, 70, 80, and 90. For the same L* value, the sRGB and AdobeRGB color subspaces are identical where they overlap. The following material for numerically quantifying how color X differs materially from color A uses the sRGB or AdobeRGB subspace as a baseline for applying the numerical quantification to the full CIE L*a*b* space. 
     Colors A and X have respective lightnesses L A * and L X *, respective green/red parameters a A * and a X *, and respective blue/yellow parameters b A * and b X * whose values are restricted so that color X differs materially from color A. In a first general L*a*b* restriction embodiment, suitable minimum and maximum limits are placed on one or more of lightness pair L A * and L X *, red/green parameter pair a A * and a X *, and blue/yellow parameter pair b A * and b X * to define one or more pairs of mutually exclusive (non-overlapping) color regions for which any color in one of a pair of the color regions differs materially from any color in the other of that pair of color regions. Any color in one of each pair of the color regions embodies color A while any color in the other of that pair of color regions embodies color X and vice versa. 
     The color regions in one such pair of mutually exclusive color regions consist of a light region containing a selected one of colors A and X and a dark region containing the remaining one of colors A and X. Lightness L A * or L X * of selected color A or X in the light region is at least 60 greater than lightness L X * or L A * of remaining color X or A in the dark region. Selected-color lightness L A * or L X * ranges from a minimum of 60 up to 100 while remaining-color lightness L X * or L A * ranges from 0 to a maximum of 40 provided that lightnesses L A * and L X * differ by at least 60. Selected color A or X is a light color while remaining color X or A is a dark color. Each color A or X can be at any values of parameters a A * and b A * or a X * and b X *. Lightness difference ΔL*, i.e., the magnitude ΔL X *−L A *I of the difference between lightnesses L X * and L A *, is at least 60, preferably at least 70, often at least 80, sometimes at least 90. 
     Let Δa* represent the magnitude |a X *−a A *| of the difference between green/red parameters a X * and a A *, Δb* represent the magnitude |b X *−b A *| of the difference between blue/yellow parameters b X * and b A *, and ΔW* represent the weighted color difference (C L ΔL* 2 +C a Δa* 2 +C b Δb* 2 ) 1/2  where C L , C a , and C b  are non-negative weighting constants usually ranging from 0 to 1 but potentially as high as 9. Limits, almost invariably minimum limits, are placed on one or more of differences ΔL*, Δa*, Δb*, and ΔW* in a second general L*a*b* restriction embodiment such that color X differs materially from color A. In one example, each difference ΔL* or Δa* is at least 50. Each parameter b A * or b X * can be at any value. Hence, no minimum limit is placed on difference Δb*. Weighted color difference ΔW* is not used in this example. 
     Weighted color difference ΔW* can, in other examples, be used (i) alone since differences ΔL*, Δa*, and Δb* appear in the ΔW* formula (C L ΔL* 2 +C a Δa* 2 +C b Δb* 2 ) 1/2  or (ii) in combination with one or more of differences ΔL*, Δa*, and Δb*. In either case, color difference ΔW* is greater than or equal to a threshold weighted difference value ΔW th *. When used alone, threshold weighted difference value ΔW th * is sufficiently high that colors A and X materially differ for all pairs of L A *and L X * values, a A * and a X * values, and b A * and b X * values. Examination of the sRGB or AdobeRGB L* examples in Hoffmann indicates that color differences are more pronounced in green/red parameter a* than in blue/yellow parameter b*. In view of this, one of constants C L  and C a  in the ΔW* formula is sometimes greater than constant C b  while the other of constants C L  and C a  in the ΔW* formula is greater than or equal to constant C b . Constants C L  and C a  for this situation are typically 1 with constant C b  being 0. 
     A third general L*a*b* restriction embodiment combines placing limits on one or more of lightnesses L A * and L X *, red/green parameters a A * and a X *, and blue/yellow parameters b A * and b X * with placing limits on one or more of differences ΔL*, Δa*, Δb*, and ΔW* such that color X differs materially from color A. In one example, lightness L A * or L X * of each color A or X is at least 50 while red/green parameter difference Δa* is at least 70. No limitation is placed on parameter a A *, a X *, b A *, or b X *, lightness difference ΔL*, or blue/yellow parameter difference Δb* in this example. 
     Specific examples of pairs of materially different colors suitable for colors A and X, including some pairs covered in the three general L*a*b* restriction embodiments, include: (a) white and a non-white color having an L* value of no more than 80, preferably no more than 70; (b) an off-white color having an L* value of at least 95 and a darker color having an L* value of no more than 75, preferably no more than 65; (c) a reddish color having an a* value of at least 20, preferably at least 30, and a greenish color having an a* value of no more than −20, preferably no more than −30, each color having an L* value of at least 30, preferably at least 40; and (d) a reddish color having a b* value of at least 75 plus 1.6 times its a* value and a bluish color having a b* value of −10 minus 1.0 times its a* value, each color having an L* value of at least 30, preferably at least 40. Numerous other pairs of materially different colors, including numerous pairs of light and dark colors, are suitable for colors A and X. 
     Colors A and X often have different average wavelengths λ avg . In terms of spectral radiosity J λ , the average wavelength λ avg  of light of a particular color is: 
                     λ   avg     =         ∫   VS     ⁢     λ   ⁢           ⁢       J   λ     ⁡     (   λ   )       ⁢           ⁢   d   ⁢           ⁢   λ           ∫   VS     ⁢         J   λ     ⁡     (   λ   )       ⁢   d   ⁢           ⁢   λ                 (   A7   )               
Average wavelength λ avg  is zero for black and approximately 550 nm for white. The ratio R λavg  of the difference between the average wavelengths of X and A light to the average of their average wavelengths is:
 
                     R     λ   ⁢           ⁢   avg       =       2   ⁢            λ   avgX     -     λ   avgA                  λ   avgX     +     λ   avgA                 (   A8   )               
where λ avg x and λ avgA  respectively are the average wavelengths of X and A light as determined from the λ avg  relationship. In some embodiments of OI structure  100 , wavelength difference-to-average ratio R λavg  is at least 0.06, preferably at least 0.08, more preferably at least 0.10, even more preferably at least 0.12.
 
Object-Impact Structure Having Variable-Color Region Formed with Impact-Sensitive Changeably Reflective or Changeably Emissive Material
 
     ISCC structure  132  can be embodied in many ways. Structure  132  is sometimes basically a single material consisting of impact-sensitive changeably reflective or changeably emissive material where “changeably reflective” means that color change occurs primarily due to change in light reflection (and associated light absorption) and where “changeably emissive” means that color change occurs primarily due to change in light emission. “CR” and “CE” hereafter respectively mean changeably reflective and changeably emissive. 
     First consider ISCC structure  132  consisting solely of impact-sensitive CR material. “IS” hereafter means impact-sensitive. During the normal state, CR ISCC structure  132  reflects ARic light striking SF zone  112 . No significant amount of light is normally emitted by structure  132 . Including any ARsb light passing through structure  132 , A light is formed with ARic light and any ARsb light normally leaving structure  132 , and thus VC region  106 , via zone  112 . 
     The IS CR material forming ISCC segment  142  temporarily reflects XRic light striking print area  118  in response to object  104  impacting OC area  116  so as to meet the TH impact criteria. As in the normal state, CR ISCC segment  142  does not emit any significant amount of light during the changed state. Including any XRsb light passing through segment  142 , X light is formed with XRic light and any XRsb light temporarily leaving segment  142 , and thus IDVC portion  138 , via area  118 . 
     The mechanism causing CR ISCC segment  142  to temporarily reflect XRic light is pressure or/and deformation at OC area  116  or/and SF DF area  122  due to the impact. The IS CR material is typically piezochromic material which temporarily changes color when subjected to a change in pressure, here at print area  118 . Examples of piezochromic material are described in Fukuda,  Inorganic Chromotropism: Basic Concepts and Applications of Colored Materials  (Springer), 2007, pp. 28-32, 37, 38, and 199-238, and the references cited on those pages, contents incorporated by reference herein. 
     When ISCC structure  132  consists solely of impact-sensitive CE material, CE ISCC structure  132  may or may not significantly emit AEic light during the normal state. Structure  132  normally reflects ARic light striking SF zone  112 . Including any ARsb light passing through structure  132 , A light is formed with ARic light and any AEic and ARsb light normally leaving structure  132 , and thus VC region  106 , via zone  112 . 
     The IS CE material forming ISCC segment  142  temporarily emits XEic light in response to the impact so as to meet the TH impact criteria. During the changed state, CE ISCC segment  142  usually reflects ARic light striking print area  118 . Including any XRsb light passing through segment  142 , X light is formed with XEic and ARic light and any XRsb light temporarily leaving segment  142 , and thus IDVC portion  138 , via area  118 . Alternatively, the temporary emission of XEic light may so affect segment  142  that it temporarily largely ceases to reflect ARic light striking area  118  and, instead, temporarily reflects XRic light materially different from ARic light. X light is now formed with XEic and XRic light and any XRsb light temporarily leaving segment  142 , and therefore portion  138 , via area  118 . 
     The mechanism causing CE ISCC segment  142  to temporarily emit XEic light is pressure or/and deformation at SF DF area  122  due to the impact. If there normally is no significant AEic light, the IS CE material is typically piezoluminescent material which temporarily emits light (luminesces) upon being subjected to a change in pressure, here at print area  118 . Examples of piezoluminescent material are presented in “Piezoluminescence”, Wikipedia, en.wikipedia.org/wiki/Piezoluminescence, 16 Mar. 2013, 1 p., and the references cited therein, contents incorporated by reference herein. If there normally is significant AEic light, the IS CE material is typically piezochromic luminescent material which continuously emits light whose color changes when subjected to a change in pressure, again here at area  118 . 
     CC duration Δt dr  is usually automatic value Δt drau  formed by base portion Δt drbs  passively determined by the properties of the IS CR or CE material. VC region  106  may contain componentry, described below, which excites the CR or CE material so as to automatically extend automatic value Δt drau  by amount Δt drext  beyond base duration Δt drbs . 
     Object-Impact Structure Having Separate Impact-Sensitive and Color-Change Components 
     VC region  106  often contains multiple subregions stacked one over another up to SF zone  112 . A recitation that light of a particular species, i.e., light identified by one or more alphabetic or alphanumeric characters, leaves a specified one of these subregions mean that the light leaves the specified subregion along zone  112  if the specified subregion extends to zone  112  or, if the specified subregion adjoins another subregion lying between the specified subregion and zone  112 , along the adjoining subregion, i.e., via the interface between the two subregions. A recitation that light of a particular species leaves a segment or part of the specified subregion similarly mean that the light leaves that segment or subregion part along the corresponding segment or part of zone  112  if the specified subregion extends to zone  112  or, if the specified subregion adjoins another subregion lying between the specified subregion and zone  112 , along the corresponding segment or part of the adjoining subregion, i.e., via the corresponding segment or part of the interface between the two subregions. 
       FIGS. 11 a -11 c    (collectively “ FIG. 11 ”) illustrate an embodiment  180  of OI structure  130  in which VC region  106  is again formed solely with ISCC structure  132 . Region  106 , and thus structure  132 , here consists of a principal IS component  182  and a principal CC component  184  that meet at a flat principal light-transmission interface  186  extending parallel to SF zone  112  and interface  136 . See  FIG. 11 a   . IS component  182  extends between zone  112  and interface  186 . CC component  184  extends between interfaces  186  and  136  and therefore between IS component  182  and substructure  134 . 
     Light travels through IS component  182 , usually transparent, from SF zone  112  to interface  186  and vice versa. Preferably, largely no light striking CC component  184  along interface  186  passes fully through component  184  to interface  136 . All light striking component  184  along interface  186  is preferably absorbed and/or reflected by component  184  so that there is no substructure-reflected ARsb or XRsb light. 
     Light, termed ADcc light, normally leaves CC component  184  after being reflected or/and emitted by it during. ADcc light, which excludes any ARsb light, consists of (a) light, termed ARcc light, normally reflected by component  184  so as to leave it via interface  186  after striking SF zone  112  and passing through IS component  182  and (b) light (if any), termed AEcc light, normally emitted by component  184  so as to leave it via interface  186 . Reflected ARcc light which is of wavelength for a normal reflected main color ARcc is invariably always present. Emitted AEcc light which is of wavelength for a normal emitted main color AEcc may or may not be present. 
     Any ARsb light passes in substantial part through CC component  184 . The total light, termed ATcc light, normally leaving component  184  (along IS component  182 ) consists of ARcc light, any AEcc light, and any ARsb light leaving component  184 . Substantial parts of the ARcc light, any AEcc light, and any ARsb light pass through IS component  182 . In addition, component  182  may normally reflect light, termed ARis light, which leaves it via SF zone  112  after striking zone  112 . A light is formed with ARcc light, any AEcc light, and any ARis and ARsb light normally leaving component  182  and thus VC region  106 . Each of ADcc light and either ARcc or AEcc light is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of each of A and ADic light. 
     Referring to  FIGS. 11 b  and 11 c   , item  192  is the ID segment of IS component  182  present in IDVC portion  138 . Print area  118  is the upper surface of ID segment  192 . Item  194  is the underlying ID segment of CC component  184  present in portion  138 . Item  196  is the ID segment of interface  186  present in portion  138 . “IF” hereafter means interface. Component segments  192  and  194 , respectively termed IS and CC segments, meet along segment  196  of interface  186 . 
     Responsive to object  104  impacting OC area  116  so as to meet the TH impact criteria, ID IS segment  192  provides a principal general ID impact effect usually resulting from the pressure of the impact on area  116  or from deformation that object  104  causes along SF DF area  122 . The general ID impact effect is typically an electrical effect consisting of one or more electrical signals but can be in other form depending on the configuration and operation of IS component  182 . IS segment  192  can generate the impact effect piezoelectrically as described below for  FIGS. 24 a , 24 b , 25 a , and 25 b    or using a resistive touchscreen technique. 
     The general impact effect is furnished directly to CC component  184 , specifically to ID CC segment  194 , in some general OI embodiments. If so or if component  184 , likewise specifically segment  194 , in other general OI embodiments is provided with the general CC control signal generated in response to the impact effect for the impact meeting the basic TH impact criteria sometimes dependent on other impact criteria also being met in those other embodiments as described below, CC segment  194  responds to the effect or to the control signal by changing in such a way that light, termed XDcc light, temporarily leaves segment  194  after being reflected or/and emitted by it as VC region  106  goes to the changed state. XDcc light, which excludes any XRsb light, consists of (a) light, termed XRcc light, temporarily reflected by segment  194  so as to leave it via ID IF segment  196  after striking print area  118  and passing through IS segment  192  and (b) light (if any), termed XEcc light, temporarily emitted by CC segment  194  so as to leave it via IF segment  196 . Reflected XRcc light which is of wavelength for a temporary reflected main color XRcc is invariably always present. Emitted XEcc light which is of wavelength for a temporary emitted main color XEcc may or may not be present. 
     Any XRsb light passes in substantial part through CC segment  194 . The total light, termed XTcc light, temporarily leaving segment  194  (along IS segment  192 ) consists of XRcc light, any XEcc light, and any XRsb light leaving segment  194 . Substantial parts of the XRcc light, any XEcc light, and any XRsb light pass through IS segment  192 . Since IS component  182  may reflect ARis light during the normal state, segment  192  may reflect ARis light which leaves it via print area  118  during the changed state. X light is formed with XRcc light, any XEcc light, and any ARis and XRsb light leaving segment  192  and thus IDVC portion  138 . XDcc light differs materially from A, ADic, and ADcc light. Each of XDcc light and either XRcc or XEcc light is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of each of X and XDic light. 
     If the basic TH impact criteria consist of multiple sets (S 1 -S n ) of different principal basic TH impact criteria respectively associated with multiple specific changed colors (X i -X n ) materially different from principal color A, the principal general impact effect consists of one of multiple different principal specific impact effects respectively corresponding to the specific changed colors. IS component  182 , specifically IS segment  192 , provides the general impact effect as the specific impact effect for the basic TH criteria set (S i ) met by the impact. CC component  184 , specifically CC segment  194 , responds (a) in some general OI embodiments to that specific impact effect or (b) in other general OI embodiments to the general CC control signal then generated in response to that specific effect sometimes dependent on the above-mentioned other impact criteria also being met in those other embodiments, by causing IDVC portion  138  to appear as the specific changed color (X i ) for that criteria set. The control signal may, for example, be generatable at multiple control conditions respectively associated with the criteria sets. The control signal is then actually generated at the control condition for the criteria set met by the impact. 
     X light advantageously generally becomes more distinct from A light as the ratio R ARis/ADcc  of the radiosity of ARis light leaving IS component  182  during the normal state to the radiosity of ADcc light leaving component  182  during the normal state decreases and as the ratio R ARis/XDcc  of the radiosity of ARis light leaving IS segment  192  during the changed state to the radiosity of XDcc light leaving segment  192  during the changed state likewise decreases. The radiosity of ARis light during the normal and changed states is usually made as small as reasonably feasible. The sum of radiosity ratios R ARis/ADcc  and R ARis/XDcc  is usually no more than 0.4, preferably no more than 0.3, more preferably no more than 0.2, even more preferably no more than 0.1. 
     Performing the impact-sensing and color-changing operations with separate components  182  and  184  provides many benefits. More materials are capable of separately performing the impact-sensing and color-changing operations than of jointly performing those operations. As a result, the ambit of colors for embodying colors A and X is increased. Different shades of the embodiments of colors A and X existent in the absence of ARis light can be created by varying the reflection characteristics of IS component  182 , specifically the wavelength and intensity characteristics of ARis light, without changing CC component  184 . Print area  118  can be even better matched to OC area  116 . The ruggedness, especially the ability to successfully withstand impacts, is enhanced. Consequently, the lifetime can be increased. 
     The ability to select and control the CC timing, both CC duration Δt dr  and the XN delays, is improved. Full forward XN delay Δt f  can be as high as 0.4 s, sometimes as high as 0.6, 0.8, or 1.0 s but is usually reduced to no more than 0.2 s, preferably no more than 0.1 s, more preferably no more than 0.05 s, even more preferably no more than 0.025 s. 50% forward XN delay Δt f50  correspondingly can be as high as 0.2 s, sometimes as high as 0.3, 0.4, or 0.5 s but is usually reduced to no more than 0.1 s, preferably no more than 0.05 s, more preferably no more than 0.025 s, even more preferably no more than 0.0125 s. These low maximum usual and preferred values for delays Δt f  and Δt f50  are highly advantageous when the activity is a sport such as tennis in which players and any official(s) need to make quick decisions on the impact locations of a tennis ball embodying object  104 . 
     The last 10% of the actual print-area transition from color A to color X is comparatively long in some embodiments of OI structure  180 . As a result, the time period from OS time t os  to actual forward XN end time t f100  is considerably greater than approximate full forward delay Δt f . See  FIG. 10 . In such embodiments, the comparatively long duration of the last 10% of the A-to-X transition is generally not significant because a person viewing surface  102  can usually readily identify print area  118  when it is close to, but not exactly, color X. In view of these considerations, 90% forward XN delay Δt f90  and 10%-to-90% forward XN delay Δt f10-90  are important timing parameters. Since 90% forward delay Δt f90  starts at OS time t os  whereas 10%-to-90% forward delay Δt f10-90  starts at 10% forward XN time t f10 , delay Δt f90  can be greater than or less than delay Δt f10-90  depending on whether OS time t os  occurs before or after 10% forward XN time t f10 . By forming ISCC structure  132  with components  182  and  184 , especially when CC component  184  is configured as described below for  FIGS. 12 a -12 c   , each delay Δt f90  or Δt f100-90  can be as high as 0.4 s, sometimes as high as 0.6, 0.8, or 1.0 s but is usually less than 0.2 s, preferably less than 0.1 s, more preferably less than 0.05 s, even more preferably less than 0.025 s. This is likewise particularly advantageous when the activity is a sport such as tennis in which quick decisions are needed on tennis-ball impact locations. 
     OC duration Δt oc , although usually quite small, can be long enough that 90% forward XN time t f90  occurs before OS time t os  when ISCC structure  132  is formed with components  182  and  184 . If so, 90% forward XN delay Δt f90  and 10%-to-90% forward XN delay Δt f10-90  become zero. Also, approximate forward XN end time t fe  may occur before OS time t os . If so, full forward delay Δt f  drops to zero. 50% forward XN delay Δt f50  also drops to zero and, in fact, becomes zero whenever time t 50  occurs before OS time t os . 
     A consequence of the reduced maximum Δt f , Δt f50 , Δt f90 , and Δt f10-90  values arising from forming ISCC structure  132  with components  182  and  184  is that return XN delays Δt r , Δt r50 , Δt r90 , and Δt r10-90  are reduced. Approximate full return XN delay Δt r  usually has the same reduced maximum values as full forward delay Δt f . 50% return XN delay Δt r50  usually has the same reduced maximum values as 50% forward delay Δt f50 . 90% return XN delay Δt r90  and 10%-to-90% return XN delay Δt r10-90  usually have the same reduced maximum values as forward delays Δt f90  and Δt f10-90 . 
     The general impact effect can be transmitted outside VC region  106 . For instance, the effect can take the form of a general location-identifying impact signal supplied to a separate general CC duration controller as described below for  FIGS. 54 a  and 54 b    or a characteristics-identifying impact signal supplied to a separate general intelligent CC controller as described below for  FIGS. 64 a  and 64 b   . The effect can also take the form of multiple cellular location-identifying impact signals supplied to a separate cell CC duration controller as described below for  FIGS. 59 a  and 59 b    or multiple characteristics-identifying impact signals supplied to a separate intelligent cell CC controller as described below for  FIGS. 69 a  and 69 b   . When a duration controller is used, the effect is also provided to ID portion  138 , or is converted into the general CC control signal provided to portion  138 , for producing a color change at print area  118 . However, the effect is not provided to portion  138  or always converted into the control signal when an intelligent controller is used. Instead, the intelligent controller makes a decision to provide, or not provide, portion  138  with a CC initiation signal which implements, or leads to the generation of, the control signal that produces a color change at area  118 . 
     The positions of components  182  and  184  can sometimes be reversed so that IS component  182  extends between CC component  184  and substructure  134 . SF zone  112  is then the upper surface of component  184 . Components  182  and  184  still meet at interface  186 . In this reversal, the pressure of the impact on OC area  116  or the deformation that object  104  causes along SF DF area  122  is transmitted pressure-wise through component  184  to produce excess internal pressure at IF segment  196 . IS segment  192  responds to the excess internal pressure at IF segment  196 , and thus to object  104  impacting OC area  116  so as to meet excess internal pressure criteria that embody the TH impact criteria, by providing the general impact effect supplied to CC segment  194  or/and outside VC region  106  for potential generation of the general CC control signal. 
     Object-Impact Structure Having Impact-Sensitive Component and Changeably Reflective or Changeably Emissive Color-Change Component 
     CC component  184  in OI structure  180  can be embodied in various ways to perform the CC function in accordance with the invention. In one group of embodiments, the core of the mechanism used to achieve color changing is light reflection (and associated light absorption). Component  184  in these embodiments is, for simplicity, termed “CR component  184 ” where “CR” again means changeably reflective. Light emission is the core of the mechanism used to achieve color changing in another group of embodiments. Component  184  in these other embodiments is termed “CE component  184 ” where “CE” again means changeably emissive. 
     Beginning with CR component  184 , no significant amount of light is emitted by it so as to leave it during the normal or changed state. Starting with the normal state, CR component  184  normally reflects ARcc light which passes in substantial part through IS component  182 . Normal reflected main color ARcc may be termed the first reflected main color. Including any ARis light normally reflected by IS component  182  and any ARsb light passing through it, A light is formed with ARcc light and any ARis and ARsb light normally leaving component  182  and thus VC region  106 . ARcc light, a reflective implementation of ADcc light here, is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of A light. 
     Responsive (a) in some general OI embodiments to the general impact effect for the impact meeting the basic TH impact criteria or (b) in other general OI embodiments to the general CC control signal generated in response to the effect sometimes dependent on other impact criteria also being met in those other embodiments, ID segment  194  of CR component  184  temporarily reflects XRcc light, materially different from ARcc light, which passes in substantial part through IS segment  192  during the changed state. Temporary reflected main color XRcc may be termed the second reflected main color. If IS component  182  normally reflects ARis light, segment  192  continues to reflect ARis light. Including any XRsb light passing through segment  192 , X light is formed with XRcc light and any ARis and XRsb light leaving segment  192  and thus IDVC portion  138 . XRcc light, a reflective implementation of XDcc light here, is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of X light. 
     CR component  184  is an electrochromic structure or a photonic crystal structure in a basic embodiment. An electrochromic structure contains electrochromic material which temporarily changes color upon undergoing a change in electronic state, such as a change in charge condition resulting from a change in electric field across the material, in response to an electrical-effect implementation of the general impact effect provided by IS segment  192 . Examples of electrochromic material are described in Fukuda,  Inorganic Chromotropism: Basic Concepts and Applications of Colored Materials  (Springer), 2007, pp. 34-38, and 291-336, and the references cited on those pages, contents incorporated by reference herein. Alternatively, CR component  184  is one or more of the following light-processing structures in which the light processing generally involves reflecting light off particles: a dipolar suspension structure, an electrofluidic structure, an electrophoretic structure, and an electrowetting structure. CR component  184  may also be a reflective liquid-crystal structure or a reflective microelectricalmechanicalsystem (display) structure such as an interferometric modulator structure or a transflective digital micro shutter structure. 
     CE component  184  can be embodied to operate in either of two modes termed the single-emission and double-emission modes. These two embodiments of CE component  184  are respectively termed single-emission CE component  184  and double-emission CE component  184 . 
     For single-emission CE component  184 , the normal and changed states of VC region  106  can be respectively designated as non-emissive and emissive states because significant light emission occurs during the changed state but not during the normal state. Single-emission CE component  184  operates the same during the normal (non-emissive) state as CR component  184 . 
     Responsive (a) in some general OI embodiments to the general impact effect for the impact meeting the TH impact criteria or (b) in other general OI embodiments to the general CC control signal generated in response to the effect sometimes dependent on other impact criteria also being met in those other embodiments, ID segment  194  of single-emission CE component  184  temporarily emits XEcc light which passes in substantial part through IS segment  192  during the changed (emissive) state. CC segment  194  usually continues to reflect ARcc light which passes in substantial part through IS segment  192 . XEcc and ARcc light form XDcc light. Since IS component  182  may normally reflect ARis light, segment  192  may reflect ARis light. Including any XRsb light passing through segment  192 , X light is formed with XEcc and ARcc light and any ARis and XRsb light leaving segment  192  and thus IDVC portion  138 . XEcc light, an emissive component of XDcc light here, differs materially from A, ADic, ADcc, and ARcc light. Either XEcc or ARcc light is usually a majority component of X light. 
     Alternatively, the emission of XEcc light may so affect CC segment  194  of single-emission CE component  184  during the changed state that segment  194  ceases to reflect ARcc light and, instead, temporarily reflects XRcc light significantly different from ARcc light. The XRcc light passes in substantial part through IS segment  192 . XEcc and XRcc light now form XDcc light. The processing of any ARis and XRsb light is the same. X light is then formed with XEcc and XRcc light and any ARis and XRsb light leaving segment  192  and thus IDVC portion  138 . Either XEcc or XRcc light is usually a majority component of X light. 
     Turning to double-emission CE component  184 , the normal and changed states of VC region  106  can be respectively designated as first emissive and second emissive states because significant light emission occurs during both the normal and changed states. Double-emission CE component  184  operates as follows during the normal (first emissive) state. For the normal state, CE component  184  normally emits AEcc light which passes in substantial part through IS component  182 . Normal emitted main color AEcc may be termed the first emitted main color. CE component  184  usually normally reflects ARcc light which passes in substantial part through IS component  182 . Including any ARis light normally reflected by component  182  and any ARsb light passing through it, A light is formed with AEcc and ARcc light and any ARis and ARsb light normally leaving component  182  and thus VC region  106 . Either AEcc or ARcc light is usually a majority component of A light. 
     Double-emission CE component  184  responds, during the changed (second emissive) state, (a) in some general OI embodiments to the general impact effect for the impact meeting the TH impact criteria or (b) in other general OI embodiments to the general CC control signal generated in response to the effect sometimes dependent on other impact criteria also being met in those other embodiments basically the same as single-emission CE component  184  responds during the changed (emissive) state. In particular, ID segment  194  of double-emission CE component  184  temporarily emits XEcc light which passes in substantial part through IS segment  192 . Temporary emitted main color XEcc, which may be termed the second emitted main color, differs materially from normal (or first) emitted main color AEcc. CC segment  194  can implement this change by ceasing to emit AEcc light and replacing it with XEcc light or by ceasing to emit one or more components, but not all, of AEcc light, potentially accompanied by emitting additional light. 
     During the changed state, ID segment  194  of double-emission CE component  184  usually continues to reflect ARcc light which passes in substantial part through IS segment  192 . Since IS component  182  may normally reflect ARis light, segment  192  may again reflect ARis light. Including any XRsb light passing through segment  192 , X light is formed with XEcc and ARcc light and any ARis and XRsb light leaving segment  192  and thus IDVC portion  138 . Either XEcc or ARcc light is usually a majority component of X light. 
     Alternatively, the emission of XEcc light may so affect ID segment  194  of double-emission CE component  184  that CC segment  194  temporarily ceases to reflect ARcc light and instead temporarily reflects XRcc light which passes through IS segment  192 . Subject to segment  194  changing from emitting AEcc light to emitting XEcc light by ceasing to emit AEcc light and replacing it with XEcc light or by ceasing to emit one or more components, but not all, of AEcc light, possibly accompanied by emitting additional light, the operation of double-emission CE component  184  during the changed state in this alternative is the same as that of single-emission CE component  184  during the changed state in the corresponding alternative. 
     Both the single-emission and double-emission embodiments of CE component  184  are advantageous because use of light emission to produce changed color X enables print area  118  to be quite bright, thereby enhancing visibility of the color change. CE component  184 , either embodiment, may variously be one or more of the following light-processing structures that emit light: a backlit liquid-crystal structure, a cathodoluminescent structure, a digital light processing structure, an electrochromic fluorescent structure, an electrochromic luminescent structure, an electrochromic phosphorescent structure, an electroluminescent structure, an emissive microelectricalmechanicalsystem (display) structure (such as a time-multiplexed optical shutter or a backlit digital micro shutter structure), a field-emission structure, a laser phosphor (display) structure, a light-emitting diode structure, a light-emitting electrochemical cell structure, a liquid-crystal-over-silicon structure, an organic light-emitting diode structure, an organic light-emitting transistor structure, a photoluminescent structure, a plasma panel structure, a quantum-dot light-emitting diode structure, a surface-conduction-emission structure, a telescopic pixel (display) structure, and a vacuum fluorescent (display) structure. Organic light-emitting diode structures are of particular interest because they provide bendability for impact resistance. 
     The above-described situation in which the positions of components  182  and  184  are reversed is particularly suitable for embodying CC component  184  as a CR CC component, especially an electrochromic or photonic crystal structure, or a CE CC component, especially an electrochromic fluorescent, electrochromic luminescent, electrochromic phosphorescent structure, or electroluminescent structure. 
     Object-Impact Structure Having Impact-Sensitive Component and Color-Change Component that Utilizes Electrode Assembly 
       FIGS. 12 a -12 c    (collectively “ FIG. 12 ”) illustrate an embodiment  200  of OI structure  180  and thus of OI structure  130 . CC component  184  in OI structure  200  consists of a principal electrode assembly  202 , an optional principal near (first) auxiliary layer  204  extending between electrode assembly  202  and interface  186  to meet IS component  182 , and an optional principal far (second) auxiliary layer  206  extending between assembly  202  and substructure  134 . See  FIG. 12 a   . The adjectives “near” and “far” are used to differentiate near auxiliary layer  204  and far auxiliary layer  206  relative to their distances from SF zone  112 , far auxiliary layer  206  being farther from zone  112  than near auxiliary layer  204 . “NA” and “FA” hereafter respectively mean near auxiliary and far auxiliary. Assembly  202 , NA layer  204 , and FA layer and  206  all usually extend parallel to one another and parallel to zone  112  and interface  136 . 
     NA layer  204 , if present, usually contains insulating material for isolating IS component  182  and assembly  202  from each other as necessary. FA layer  206 , if present, usually contains insulating material for appropriately isolating assembly  202  from substructure  134  as desired. Auxiliary layers  204  and  206  may perform other functions. Electrical conductors may be incorporated into NA layer  204  for electrically connecting selected parts of component  182  to selected parts of assembly  202 . If VC region  106 , potentially in combination with FC region  108 , is manufactured as a separate unit and later installed on substructure  134 , FA layer  206  protects assembly  202  during the time between manufacture of the unit and its installation on substructure  134 . In some liquid-crystal embodiments of CC component  184 , NA layer  204  includes a polarizer while FA layer  206  includes a polarizer and either a light reflector or a light emitter. 
     Light travels from interface  186  through NA layer  204 , usually transparent, to assembly  202  and vice versa. Hence, light leaves assembly  202  along layer  204 . In some embodiments of CC component  184 , light also travels from interface  186  through both NA layer  204  and assembly  202  to FA layer  206  and vice versa. Light leaves FA layer  206  along assembly  202  in those embodiments. Preferably, no light striking layer  206  along assembly  202  passes fully through layer  206  to interface  136  during the normal or changed state. In particular, all light striking layer  206  along assembly  202  is preferably either absorbed or reflected by layer  206  so that there is no ARsb or XRsb light. 
     Auxiliary layers  204  and  206  may or may not be significantly involved in determining color change along print area  118 . If layer  204  or  206  is significantly involved in determining color change, the involvement is usually passive. That is, light processed by layer  204  or  206  undergoes changes largely caused by changes in light processed by assembly  202  rather than partly or fully by changes in the physical or/and chemical characteristics of layer  204  or  206 . 
     FA layer  206  (if present) operates during the normal state according to a light non-outputting normal general far auxiliary mode or one of several versions of a light outputting normal general far auxiliary mode depending on how subcomponents  202 ,  204 , and  206  are configured and constituted. “GFA” hereafter means general far auxiliary. Largely no light leaves FA layer  206  along assembly  202  in the light non-outputting normal GFA mode. The light outputting normal GFA mode consists of one or both of the following actions: (i) any ARsb light passes in substantial part through layer  206  and (ii) light, termed ADfa light, is reflected or/and emitted by layer  206  so as to leave it along assembly  202 . 
     ADfa light, which excludes any ARsb light, consists of (a) light (if any), termed ARfa light, normally reflected by FA layer  206  so as to leave it along assembly  202  after striking SF zone  112 , passing through IS component  182 , NA layer  204  (if present), and assembly  202  and (b) light (if any), termed AEfa light, normally emitted by layer  206  so as to leave it along assembly  202 . Reflected ARfa light is typically present when ADfa light is present. The total light (if any), termed ATfa light, leaving layer  206  in the light outputting normal GFA mode consists of any ARfa and AEfa light provided directly by layer  206  and any ARsb light passing through it. This operation of layer  206  applies to situations in which it is both significantly used, and not used, in determining color change along zone  112 . 
     Taking note that NA layer  204  may not be present in CC component  184 , a recitation that light leaves assembly  202  means that the light leaves it along IS component  182 , and thus via interface  186 , if layer  204  is absent. Assembly  202  operates during the normal state according to a light non-outputting normal general assembly mode or one of a group of versions of a light outputting normal general assembly mode depending on how subcomponents  202 ,  204 , and  206  are configured and constituted. “GAB” hereafter means general assembly. Largely no light normally leaves assembly  202  along NA layer  204  in the light non-outputting normal GAB mode. The light outputting normal GAB mode consists of one or more of the following actions: (i) a substantial part of any ARsb light passing through FA layer  206  passes through assembly  202 , (ii) substantial parts of any FA-layer-provided ARfa and AEfa light pass through assembly  202 , and (iii) light, termed ADab light, is reflected or/and emitted by assembly  202  so as to leave it along NA layer  204 . 
     ADab light, which excludes any ARfa or ARsb light, consists of (a) light (if any), termed ARab light, normally reflected by assembly  202  so as to leave it along NA layer  204  after striking SF zone  112 , passing through IS component  182 , and layer  204  and (b) light (if any), termed AEab light, normally emitted by assembly  202  so as to leave it along layer  204 . Reflected ARab light is typically present when ADab light is present. The total light, termed ATab light, leaving assembly  202  in the light outputting normal GAB mode consists of any ARab and AEab light provided directly by assembly  202 , any FA-layer-provided ARfa and AEfa light passing through it, and any ARsb light passing through it. 
     ADfa light is present in some versions, but absent in other versions, of the light outputting normal GAB mode. When ADfa light is absent, ARsb light is also usually absent. Emitted AEab light is typically absent from the light outputting normal GAB mode when emitted AEfa light is present in it and vice versa. Either ADab or ADfa light, and therefore one of ARab, AEab, ARfa, and AEfa light, is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of each of A, ADic, and ADcc light depending on how subcomponents  202 ,  204 , and  206  are configured and constituted. 
     Substantial parts of any ARab, AEab, ARfa, AEfa, and ARsb light leaving assembly  202  pass through NA layer  204 . In addition, layer  204  may normally reflect light, termed ARna light, which leaves it via interface  186  after striking SF zone  112  and passing through IS component  182  and which thus excludes any ARab, ARfa, or ARsb light. Total ATcc light normally leaving layer  204 , and therefore CC component  184 , consists of any assembly-provided ARab and AEab light passing through layer  204 , any FA-layer-provided ARfa and AEfa light passing through it, any ARna light reflected by it, and any ARsb light passing through it. 
     Inasmuch as any ARab, AEab, ARfa, AEfa, and ARsb light leaving NA layer  204  form ATab light leaving layer  204  via interface  186 , ATcc light leaving CC component  184  is also expressed as consisting of ATab light and any ARna light leaving layer  204 . Also, any ARab, AEab, ARfa, AEfa, and ARna light leaving layer  204  form ADcc light leaving component  184 . Substantial parts of any ARab, AEab, ARfa, AEfa, ARna, and ARsb light leaving component  184  pass through IS component  182 . Including any ARis light reflected by component  182 , A light is formed with any ARab, AEab, ARfa, AEfa, ARis, ARna, and ARsb light normally leaving component  182  and thus VC region  106 . 
     Changes in the color of IDVC portion  138  occur due to changes in assembly  202  in responding (a) in first general OI embodiments to the general impact effect provided by IS segment  192  for the impact meeting the basic TH impact criteria or (b) in second general OI embodiments to the general CC control signal generated in response to the effect sometimes dependent on other impact criteria also being met in the second embodiments. The assembly changes are sometimes accompanied, as mentioned above, by changes in the light processed by NA layer  204 , if present, or/and FA layer  206 , if present. Referring to  FIGS. 12 b  and 12 c    with this in mind, item  212  is the ID segment of assembly  202  present in portion  138 . Items  214  and  216  respectively are the ID segments of auxiliary layers  204  and  206  present in portion  138 . 
     During the changed state, ID segment  216  of FA layer  206  (if present) temporarily operates, usually passively, according to a light non-outputting changed GFA mode or one of several versions of a light outputting changed GFA mode. Largely no light leaves FA segment  216  along ID assembly segment  212  in the light non-outputting changed GFA mode, “AB” hereafter meaning assembly. The light outputting changed GFA mode consists of one or both of the following actions: (i) any XRsb light passes in substantial part through FA segment  216  and (ii) light, termed XDfa light, is reflected or/and emitted by segment  216  so as to leave it along AB segment  212 . 
     XDfa light, which excludes any XRsb light, consists of (a) light (if any), termed XRfa light, temporarily reflected by FA segment  216  so as to leave it along AB segment  212  after striking print area  118 , passing through IS segment  192 , ID segment  214  of NA layer  204  (if present), and AB segment  212  and (b) light (if any), termed XEfa light, temporarily emitted by FA segment  216  so as to leave it along AB segment  212 . Reflected XRfa light is typically present when XDfa light is present. Reflection of XRfa light or/and emission of XEfa light leaving FA segment  216  along AB segment  212  usually occur under control of segment  212  in response (a) in the first general OI embodiments to the general impact effect for the impact meeting the basic TH impact criteria or (b) in the second general OI embodiments to the general CC control signal generated in response to the effect sometimes dependent on other impact criteria also being met in the second embodiments. If FA layer  206  normally reflects ARfa light or/and emits AEfa light, a change in which largely no light temporarily leaves FA segment  216  likewise usually occurs under control of AB segment  212  in responding to the impact effect or to the control signal. The total light (if any), termed XTfa light, leaving FA segment  216  in the light outputting changed GFA mode consists of any XRfa and XEfa light provided directly by segment  216  and any XRsb light passing through it. 
     The foregoing operation of FA segment  216  applies to situations in which FA layer  206  is both significantly used, and not used, in determining color change along print area  118 . XDfa light usually differs materially from A, ADic, ADcc, ADab, and ADfa light if layer  206  is significantly involved in determining color change along area h. The same applies usually to XRfa and XEfa light if both are present and, of course, to XRfa or XEfa light if it is present but respective XEfa or XRfa light is absent. 
     Again noting that NA layer  204  may not be present in CC component  184 , a recitation that light leaves AB segment  212  means that the light leaves segment  212  along IS segment  192 , and thus via IF segment  196 , if layer  204  is absent. During the changed state, AB segment  212  responds (a) in the first general OI embodiments to the general impact effect or (b) in the second general OI embodiments to the general CC control signal generated in response to the effect sometimes dependent on both the TH impact criteria and other criteria being met by temporarily operating according to a light non-outputting changed GAB mode or one of a group of versions of a light outputting changed GAB mode. Largely no light leaves segment  212  along NA segment  214  in the light non-outputting changed GAB mode. The light outputting changed GAB mode consists of one or more of the following actions: (i) a substantial part of any XRsb light passing through FA segment  216  passes through AB segment  212 , (ii) substantial parts of any FA-segment-provided XRfa and XEfa light pass through segment  212 , and (iii) light, termed XDab light, is reflected or/and emitted by segment  212  so as to leave it along NA segment  214 . 
     XDab light, which excludes any XRfa or XRsb light, consists of (a) light (if any), termed XRab light, temporarily reflected by AB segment  212  so as to leave it along NA segment  214  after striking print area  118 , passing through IS segment  192  and NA segment  214  and (b) light (if any), termed XEab light, temporarily emitted by AB segment  212  so as to leave it along NA segment  214 . Reflected XRab light is typically present when XDab light is present. The total light, termed XTab light, leaving AB segment  212  in the light outputting changed GAB mode consists of any XRab and XEab light provided directly by segment  212 , any FA-segment-provided XRfa and XEfa light passing through it, and any XRsb light passing through it. 
     XDfa light is present in some versions, but is absent in other versions, of the light outputting changed GAB mode. When XDfa light is absent, XRsb light is also usually absent. Emitted XEab light is typically absent from the light outputting changed GAB mode when emitted XEfa light is present in it and vice versa. XDab light usually differs materially from A, ADic, ADcc, ADab, and ADfa light if FA layer  206  is not significantly involved in determining color change along print area  118 . The same applies usually to XRab and XEab light if both are present and, of course, to XRab or XEab light if it is present but respective XEab or XRab light is absent. Either XDab or XDfa light, and thus one of XRab, XEab, XRfa, and XEfa light, is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of each of X, XDic, and XDcc light depending on the configuration and constitution of subcomponents  202 ,  204 , and  206 . 
     Substantial parts of any XRab, XEab, XRfa, XEfa, and XRsb light leaving AB segment  212  pass through NA segment  214 . In addition, segment  214  may reflect light, termed XRna light, which leaves it via IF segment  196  during the changed state after striking print area  118  and passing through IS segment  192  and which thus excludes any XRab, XRfa, or XRsb light. XRna light is usually largely ARna light. If NA segment  214  undergoes a change so that XRna light significantly differs from ARna light, the change usually occurs under control of AB segment  212  in responding to the general impact effect or to the general CC control signal. Total XTcc light temporarily leaving NA segment  214 , and therefore CC segment  194 , consists of any AB-segment-provided XRab and XEab light passing through segment  214 , any FA-segment-provided XRfa and XEfa light passing through it, any XRna light directly reflected by it, and any XRsb light passing through it. 
     Inasmuch as any XRab, XEab, XRfa, XEfa, and XRsb light leaving NA segment  214  form XTab light leaving it via IF segment  196 , XTcc light leaving CC segment  194  is also expressed as consisting of XTab light and any XRna light leaving NA segment  214 . Any XRab, XEab, XRfa, XEfa, and XRna light leaving segment  214  form XDcc light leaving CC segment  194 . Substantial parts of any XRab, XEab, XRfa, XEfa, XRna, and XRsb light leaving segment  194  pass through IS segment  192 . If IS component  182  normally reflects ARis light, segment  192  continues to reflect ARis light. X light is formed with any XRab, XEab, XRfa, XEfa, ARis, XRna, and XRsb light temporarily leaving segment  192  and thus IDVC portion  138 . 
     Different shades of the embodiments of colors A and X occurring in the absence of ARna and XRna light can be created by varying the reflection characteristics of NA layer  204 , specifically the wavelength and intensity characteristics of ARna and XRna light, without changing assembly  202  or FA layer  206 . NA layer  204  can thus strongly influence color A or/and color X. 
     Either of the changed GAB modes, including any of the versions of the light outputting changed GAB mode, can generally be employed with either of the normal GAB modes, including any of the versions of the light outputting normal GAB mode, in an embodiment of CC component  184  except for employing the light non-outputting changed GAB mode with the light non-outputting normal GAB mode provided, however, that the operation of the changed GAB mode is compatible with the operation of normal GAB mode in that embodiment. This compatibility requirement may effectively preclude employing certain versions of the light outputting changed GAB mode with certain versions of the light outputting normal GAB mode. 
     When two versions of the light outputting normal GAB mode differ only in that ARsb light is present in one of the versions and absent in the other, the difference is generally of a relatively minor nature. The same applies when the only difference between two versions of the light outputting changed GAB mode is that XRsb light is present in one of the versions and absent in the other. Subject to the preceding compatibility requirement, the major combinations of one of the changed GAB modes with one of the normal GAB modes consist of employing the light non-outputting changed GAB mode or the light outputting changed GAB mode for a version in which (a) XRfa or/and XEfa light provided by FA segment  216  passes through AB segment  212  or/and (b) XRab or/and XEab light is provided directly by segment  212  with the light non-outputting normal GAB mode or the light outputting normal GAB mode for a version in which (a) ARfa or/and AEfa light provided by FA layer  206  passes through assembly  202  or/and (b) ARab or/and AEab light is provided directly by assembly  202  again except for employing the light non-outputting changed GAB mode with the light non-outputting normal GAB mode. 
     Configuration and General Operation of Electrode Assembly 
     Electrode assembly  202  in OI structure  200  consists of a principal core layer  222 , principal near (first) electrode structure  224 , and principal far (second) electrode structure  226  located generally opposite, and spaced apart from, near electrode structure  224 . Core layer  222  lies between electrode structures  224  and  226 . “NE” and “FE” hereafter respectively mean near electrode and far electrode. FE structure  226  is farther away from SF zone  112  than NE structure  224  so that structures  224  and  226  respectively meet auxiliary layers  204  and  206 . Core layer  222  and structures  224  and  226  all usually extend parallel to one another and to auxiliary layers  204  and  206 , zone  112 , and interface  136 . Each structure  224  or  226  contains a layer (not separately shown) for conducting electricity. Structures  224  and  226  control core layer  222  as further described below and typically process light, usually passively, which affects the operation of layer  222  and thus CC component  184 . 
     Light travels from NA layer  204  or, if it is absent, from interface  186  through NE structure  224  (including its electrode layer) to core layer  222  and vice versa. Accordingly, light leaves layer  222  along structure  224 . In some embodiments of CC component  184 , light travels from interface  186  through structure  224 , layer  222 , and FE structure  226  (similarly including its electrode layer) to FA layer  206  and vice versa so that light leaves layer  206  along structure  226 . 
     FE structure  226  operates as follows during the normal state. When assembly  202  is in the light non-outputting normal GAB mode, largely no light leaves structure  226  along core layer  222 . One or more of the following actions occur with structure  226  when assembly  202  is in the light outputting normal GAB mode: (i) a substantial part of any ARsb light passing through FA layer  206  (if present) passes through structure  226 , (ii) substantial parts of any ARfa and AEfa light provided by layer  206  pass through structure  226 , and (iii) structure  226  reflects light, termed ARfe light, which leaves it along core layer  222  after striking SF zone  112  and passing through IS component  182 , NA layer  204  (if present), NE structure  224 , and core layer  222  and which thus excludes any ARfa or ARsb light. The total light (if any), termed ATfe light, normally leaving structure  226  consists of any ARfa and AEfa light provided by FA layer  206  so as to pass through structure  226 , any ARfe light directly reflected by it, and any ARsb light passing through it. 
     Core layer  222  operates as follows during the normal state. When assembly  202  is in the light non-outputting normal GAB mode, largely no light normally leaves layer  222  along NE structure  224 . One or more of the following actions occur with layer  222  when assembly  202  is in the light outputting normal GAB mode so as to implement it for layer  222 : (i) a substantial part of any ARsb light passing through FE structure  226  passes through layer  222 , (ii) substantial parts of any FA-layer-provided ARfa and AEfa light passing through structure  226  pass through layer  222 , (iii) a substantial part of any ARfe light reflected by structure  226  passes through layer  222 , and (iv) light, termed ADcl light and of wavelength for a normal reflected/emitted core color ADcl, is reflected or/and emitted by layer  222  so as to leave it along NE structure  224 . 
     ADcl light, which excludes any ARfe, ARfa, or ARsb light, consists of (a) light (if any), termed ARcl light and of wavelength for a normal reflected core color ARcl, normally reflected by core layer  222  so as to leave it along NE structure  224  after striking SF zone  112 , passing through IS component  182 , NA layer  204 , and structure  224  and (b) light (if any), termed AEcl light and of wavelength for a normal emitted core color AEcl, normally emitted by core layer  222  so as to leave it along structure  224 . Reflected ARcl light is typically present when ADcl light is present. The total light, termed ATcl light and of wavelength for a normal total core color ATcl, leaving layer  222  in the light outputting normal GAB mode consists of any ARcl and AEcl light provided directly by layer  222  and any ARfa, AEfa, ARfe, and ARsb light passing through it. 
     Emitted AEcl light is typically absent from the light outputting normal GAB mode when emitted AEfa light is present in it and vice versa. When ADfa light is absent, each of ADcl light and either ARcl or AEcl light is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of each of A, ADic, ADcc, and ADab light depending on how subcomponents  202 ,  204 , and  206  are configured and constituted. 
     Substantial parts of any ARcl, AEcl, ARfa, AEfa, ARfe, and ARsb light normally leaving core layer  222  pass through NE structure  224 . In addition, structure  224  may normally reflect light, termed ARne light, which leaves it along NA layer  204  after striking SF zone  112  and passing through IS component  182  and layer  204  and which thus excludes any ARcl, ARfa, ARfe, or ARsb light. Total ATab light normally leaving structure  224 , and therefore assembly  202 , consists of any ARcl, AEcl, ARfa, AEfa, ARfe, and ARsb light passing through structure  224  and any ARne light directly reflected by it. 
     Any ARcl, AEcl, ARne, and ARfe light leaving NE structure  224  form ADab light leaving assembly  202 . Any ARcl, AEcl, ARfa, AEfa, ARna, ARne, and ARfe light leaving NA layer  204  form ADcc light leaving CC component  184 . Additionally, ARcc light reflected by component  184  consists of any ARab, ARfa, and ARna light, ARab light being formed with any ARcl, ARne, and ARfe light. AEcc light emitted by component  184  consists of any AEab and AEfa light, AEab light being formed with any AEcl light. 
     Changes in AB segment  212  during the changed state arise from electrical signals applied to electrode structures  224  and  226  in response (a) in the first general OI embodiments to the general impact effect provided by IS segment  192  for the impact meeting the basic TH impact criteria or (b) in the second general OI embodiments to the general CC control signal generated in response to the effect sometimes dependent on other impact criteria also being met in the second embodiments. Referring again to  FIGS. 12 b  and 12 c   , item  232  is the ID segment of core layer  222  present in IDVC portion  138 . Items  234  and  236  respectively are the ID segments of structures  224  and  226  present in portion  138 . 
     ID FE segment  236  operates as follows during the changed state. When assembly  202  is in the light non-outputting changed GAB mode, largely no light leaves FE segment  236  along ID core segment  232 . One or more of the following actions occur with FE segment  236  when assembly  202  is in the light outputting changed GAB mode: (i) a substantial part of any XRsb light passing through ID segment  216  of FA layer  206  (if present) passes through segment  236 , (ii) substantial parts of any XRfa and XEfa light provided by FA segment  216  pass through segment  236 , and (iii) segment  236  reflects light, termed XRfe light, which leaves it along core segment  232  after striking print area  118  and passing through IS segment  192 , segment  214  of NA layer  204  (if present), ID NE segment  234 , and core segment  232  and which thus excludes any XRfa or XRsb light. The total light (if any), termed XTfe light, temporarily leaving FE segment  236  consists of any FA-segment-provided XRfa and XEfa light passing through segment  236 , any XRfe light directly reflected by it, and any XRsb light passing through it. XRfe light can be the same as, or significantly different from, ARfe light depending on how the light processing in IDVC portion  138  during the changed state differs from the light processing in VC region  106  during the normal state. 
     Core segment  232  responds (a) in the first general OI embodiments to the general impact effect or (b) in the second general OI embodiments to the general CC control signal generated in response to the effect sometimes dependent on both the TH impact criteria and other criteria being met by temporarily operating as follows during the changed state. When assembly  202  is in the light non-outputting changed GAB mode, largely no light leaves segment  232  along NE segment  234 . One or more of the following actions occur in core segment  232  when assembly  202  is in the light outputting changed GAB mode so as to implement it for segment  232 : (i) a substantial part of any XRsb light passing through FE segment  236  passes through core segment  232 , (ii) substantial parts of any FA-segment-provided XRfa and XEfa light passing through FE segment  236  pass through core segment  232 , (iii) a substantial part of any XRfe light reflected by FE segment  236  passes through core segment  232 , and (iv) light, termed XDcl light and of wavelength for a temporary reflected/emitted core color XDcl, is reflected or/and emitted by segment  232  so as to leave it along NE segment  234 . 
     XDcl light, which excludes any XRfa, XRfe, or XRsb light, consists of (a) light (if any), termed XRcl light and of wavelength for a temporary reflected core color XRcl, temporarily reflected by core segment  232  so as to leave it along NE segment  234  after striking print area  118 , passing through IS segment  192 , NA segment  214 , and NE segment  234  and (b) light (if any), termed XEcl light and of wavelength for a temporary emitted core color XEcl, temporarily emitted by core segment  232  so as to leave it along NE segment  234 . Reflected XRcl light is typically present when XDcl light is present. The total light, termed XTcl light and of wavelength for a temporary total core color XTcl, leaving core segment  232  in the light outputting changed GAB mode consists of any XRcl and XEcl light provided directly by segment  232  and any XRfa, XEfa, XRfe, and XRsb light passing through it. XTcl light differs materially from ATcl light. 
     Emitted XEcl light is typically absent from the light outputting changed GAB mode when emitted XEfa light is present in it and vice versa. XDcl light usually differs materially from A, ADic, ADcc, ADab, ADcl, and ADfa light if FA layer  206  is not significantly involved in determining color change along print area  118 . The same applies usually to XRcl and AEcl light if both are present and, of course, to XRcl or XEcl light if it is present but respective XEcl or XRcl light is absent. When XDfa light is absent, each of XDcl light and either XRcl or XEcl light is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of each of X, XDic, XDcc, and XDab light depending on how subcomponents  202 ,  204 , and  206  are configured and constituted. 
     Substantial parts of any XRcl, XEcl, XRfa, XEfa, XRfe, and XRsb light leaving core segment  232  during the changed state pass through NE segment  234 . If NE structure  224  reflects ARne light during the normal state, segment  234  reflects light, termed XRne light, which leaves it along NA segment  214  during the changed state after striking print area  118  and passing through IS segment  192  and NA segment  214  and which thus excludes any XRcl, XRfa, XRfe, or XRsb light. XRne light is usually largely ARne light. If XRne light significantly differs from ARne light, the difference usually arises due to segment  214  undergoing a change under control of AB segment  212  in responding to the general impact effect or to the general CC control signal. Total XTab light temporarily leaving NE segment  234 , and therefore AB segment  212 , consists of any XRcl, XEcl, XRfa, XEfa, XRfe, and XRsb light passing through NE segment  234  and any XRne light reflected by it. XTab light differs materially from ATab light. 
     Any XRcl, XEcl, XRne, and XRfe light leaving NE segment  234  form XDab light leaving AB segment  212 . Any XRcl, XEcl, XRfa, XEfa, XRna, XRne, and XRfe light leaving NA segment  214  form XDcc light leaving CC segment  194 . Also, XRcc light reflected by segment  194  consists of any XRab, XRfa, and XRna light, XRab light being formed with any XRcl, XRne, and XRfe light. XEcc light emitted by segment  194  consists of any XEab light and any XEfa light, XEab light being formed with any XEcl light. 
     Expanding on what was stated above in order to accommodate light reflected by NE structure  224 , when two versions of the light outputting normal GAB mode differ only in that ARne or/and ARsb light is present in one of the versions and absent in the other version, the difference is generally of a relatively minor nature. The same applies when the only difference between two versions of the light outputting changed GAB mode is that XRne or/and XRsb light is present in one of the versions and absent in the other version. Subject to the above-mentioned compatibility requirement and particularizing to light provided by core layer  222 , the major combinations of one of the changed GAB modes with one of the normal GAB modes consist of employing the light non-outputting changed GAB mode or the light outputting changed GAB mode for a version in which (a) XRfa or/and XEfa light provided by FA segment  216  passes through AB segment  212  or/and (b) XRcl or/and XEcl light provided by core segment  232  passes through NE segment  234  with the light non-outputting normal GAB mode or the light outputting normal GAB mode for a version in which (a) ARfa or/and AEfa light provided by FA layer  206  passes through assembly  202  or/and (b) ARcl or/and AEcl light provided by core layer  222  passes through NE structure  224  again except for employing the light non-outputting changed GAB mode with the light non-outputting normal GAB mode. 
     The reliability and longevity of OI structure  200  are generally enhanced when the pressure inside assembly  202 , specifically inside core layer  222 , is close to atmospheric pressure. More particularly, the average pressure across layer  222  of any fluid (liquid or/and gas) in layer  222  during operation of structure  200  is preferably at least 0.25 atm, more preferably at least 0.5 atm, even more preferably at least 0.75 atm, yet more preferably at least 0.9 atm, and is preferably no more than 2 atm, more preferably no more than 1.5 atm, even more preferably no more than 1.25 atm, yet more preferably no more than 1.1 atm. 
     Electrode Layers and their Characteristics and Compositions 
     The electrode layers of NE structure  224  and FE structure  226  are respectively termed NE and FE layers and can be embodied in various ways. Each NE or FE layer may be implemented with two or more electrode sublayers. In one embodiment, each electrode layer is a patterned layer laterally extending largely across the full extent of VC region  106 . In another embodiment, one electrode layer, typically the NE layer, is a patterned layer extending largely across the full lateral extent of region  106  while the other electrode layer is a blanket layer (or sheet) extending largely across the full lateral extent of region  106 . 
     Each patterned electrode layer may consist of one electrode or multiple electrodes spaced laterally apart from one another. The space to the sides of each patterned electrode layer is typically largely occupied with insulating material but can be largely empty or largely occupied with gas such as air. If each patterned electrode layer consists of multiple electrodes, one or more layers of conductive material may lie over or/and under the electrodes for electrical contacting them. 
     When each electrode layer is a patterned layer formed with multiple electrodes, the patterns can be the same such that the electrodes in each electrode layer lie respectively opposite the electrodes in the other electrode layer. The cellular structures described below for VC region  106  in regard to  FIGS. 38 a , 38 b , 43 a , 43 b , 46 a , 46 b , 48 a , 48 b , 50 a , 50 b   , and  53  present examples in which each electrode layer is a patterned layer consisting of multiple electrodes with the space to the sides of the electrodes largely occupied with insulating material and with the electrodes in each electrode layer lying respectively opposite the electrodes in the other electrode layer. Alternatively, the patterns in the electrode layers can differ materially so that the electrodes in the NE layer materially overlap the electrodes in the FE layer at selected sites across region  106 . 
     In a third embodiment of electrode structures  224  and  226 , each electrode layer is a blanket layer laterally extending largely across the full extent of VC region  106 . The conductivity of one of the blanket electrode layers, typically the NE layer, is usually so low that a voltage applied to a specified point in that blanket layer attenuates relatively rapidly in spreading across the layer so as to effectively be received only in a relatively small area containing the voltage-application point of that electrode layer. 
     Core layer  222  contains thickness locations, termed chief core thickness locations, lying between opposite portions of the electrode layers, e.g., thickness locations extending perpendicular to both electrode layers. Depending on how the electrode layers are configured, layer  222  may also have thickness locations, termed subsidiary core thickness locations, not lying between opposite portions of the electrode layers. A subsidiary core thickness location occurs when an infinitely long straight line extending through that location generally parallel to its lateral surfaces, generally parallel to the lateral surfaces of the nearest chief core thickness location, and generally perpendicular to the electrode layers extends through only one of the electrode layers or through neither electrode layer. Let (a) V n  represent the controllable voltage, termed the near (or first) controllable voltage, at any point in the NE layer, (b) V f  represent the controllable voltage, termed the far (or second) controllable voltage, at any point in the FE layer, and (c) V nf  represent the control voltage difference V n −V f  between controllable voltages V n  and V f  at those two points in the electrode layers. With the foregoing in mind, OI structure  200 , including assembly  202 , operates as follows. 
     Referring to  FIG. 12 a   , near controllable voltage V n  is normally largely at the same near normal control value V nN  throughout the NE layer regardless of whether it consists of one electrode, patterned or unpatterned (blanket), or multiple electrodes. Similarly, far controllable voltage V f  is normally largely at the same far normal control value V fN  throughout the FE layer regardless of whether it is formed with a single electrode, patterned or unpatterned, or multiple electrodes. Let V nfN  represent the normal value V nN −V fN  of control voltage V nf  constituted as difference V n −V f . Ignoring any dielectric or semiconductor material between core layer  222  and either electrode layer, the electrode layers normally apply (a) a voltage equal to normal control value V nfN  across essentially every chief thickness core location and (b) a voltage of the same sign as, but of lesser magnitude than, normal value V nfN  across any subsidiary thickness core location. 
     The characteristics of core layer  222  and the core-layer voltage distribution resulting from normal control value V nfN  are chosen so that, during the normal state, total ATab light consists of any ADab, ADfa, and ARsb light. Again, ADab light again consists of any ARcl, AEcl, ARne, and ARfe light while ADfa light consists of any ARfa and AEfa light. NA layer  204  is sufficiently transmissive of ATab light that ATcc light formed with ATab light and any ARna light normally leaves CC component  184 . Similarly, IS component  182  is sufficiently transmissive of ATcc light that A light formed with ATcc light and any ARis light normally leaves VC region  106 . 
     VC region  106  often provides the principal general CC control signal in response to the general impact effect supplied by IS segment  192 . Referring to  FIGS. 12 b  and 12 c   , the control signal consists of changing control voltage V nf  for IDVC portion  138  to a changed control value V nfC  materially different from normal control value V nfN . Region  106  goes to the changed state. The control signal as formed with changed control value V nfC  can be generated by various parts of region  106 , e.g., by component  182 , specifically segment  192 , or by a portion, such as NA layer  204 , of CC component  184 . Voltage V nf  remains substantially at normal value V nfN  for the remainder of region  106 . 
     The general CC control signal can alternatively originate outside VC region  106 . For instance, the control signal can be a general CC initiation signal conditionally supplied from an intelligent CC controller as described below for  FIGS. 64 a  and 64 b   . In a cellular embodiment of assembly  202  as described below for  FIGS. 43 a  and 43 b , 46 a  and 46 b , 48 a  and 48 b , 50 a  and 50 b   , or  53 , the control signal can consist of multiple cellular CC initiation signals supplied respectively to full CM cells, specifically to their electrode parts, as described below for  FIG. 71 or 73 . 
     The general CC control signal is applied between a voltage-application location in the NE layer and a voltage-application location in the FE layer. “VA” hereafter means voltage-application. At least one of the VA locations is in ID segment  194  of CC component  184  and depends on where object  104  contacts SF zone  112 . Near controllable voltage V n  at the VA location in the NE layer is then at a near (or first) CC control value V nC . Far controllable voltage V f  at the VA location in the FE layer is at a far (or second) CC control value V fC . Depending on how the control signal is generated, CC values V nC  and V fC  may be respectively the same as, or respectively differ from, normal values V nN  and V fN  as long as far CC value V fC  differs materially from far normal value V fN  if near CC value V nC  is the same as near normal value V nN  and vice versa. In any event, CC values V nC  and V fC  are chosen so that changed value V nfC  differs materially from normal value V nfN . 
     The VA locations in the electrode layers can be variously implemented depending on their configurations. If each electrode layer is a patterned layer, the VA location in the NE layer extends partly or fully across ID segment  234  of NE structure  224 , and the VA location in the FE layer extends partly or fully across ID segment  236  of FE structure  226 . If one of the electrode layers, typically the NE layer, is a patterned layer while the other electrode layer is a blanket layer, the VA location in the patterned electrode layer extends partly or fully across its electrode segment  234  or  236 , and the VA location in the other electrode layer extends partly or fully across the other electrode segment  236  or  234  and laterally beyond that other electrode segment  236  or  234 , e.g., across the full lateral extent of VC region  106 . If either patterned electrode layer consists of multiple electrodes, the VA location in that multi-electrode electrode layer may partly or fully encompass two or more of its electrodes. 
     If each electrode layer is a blanket layer with the conductivity of one of the electrode layers, again typically the NE layer, being so low that a voltage applied to a specified point in that blanket electrode layer attenuates relatively rapidly in spreading across it so as to effectively be received only in a relatively small area containing that layer&#39;s VA point, the small area in that blanket electrode layer constitutes its VA location and lies in electrode segment  234  or  236  where voltage V n  or V f  is effectively received at CC value V nC  or V fC . The VA location in the other electrode layer usually extends partly or fully across its electrode segment  236  or  234  and laterally beyond its electrode segment  236  or  234 , e.g., again across the full lateral extent of VC region  106 . 
     The common feature of the preceding ways of configuring the electrode layers is that the general CC control signal is applied between electrode segments  234  and  236 . Ignoring any dielectric or semiconductor material between core layer  222  and either electrode layer, electrode segments  234  and  236  temporarily apply (a) a voltage equal to changed control value V nfC  across essentially every chief thickness core location in core segment  232  and (b) a voltage of the same sign as, but of lesser magnitude than, changed value V nfC  across any subsidiary thickness core location in segment  232 . If there is no subsidiary thickness location in segment  232 , the control signal is simply applied across segment  232 , again ignoring any dielectric or semiconductor material between core layer  222  and either electrode layer. 
     The characteristics of core layer  222  and the core-segment voltage distribution resulting from changed value V nfC  are chosen so that core segment  232  responds to the general CC control signal, and thus to the general impact effect from which the control signal is generated for the impact meeting the basic TH impact criteria sometimes dependent on other impact criteria also being met, by undergoing internal change that enables XTab light leaving AB segment  212  to consist of any XDab, XDfa, and XRsb light. Again, XDab light consists of any XRcl, XEcl, XRne, and XRfe light while XDfa light consists of any XRfa and XEfa light. NA layer  204  is sufficiently transmissive of XTab light that XTcc light formed with XTab light and any XRna light temporarily leaves CC segment  194 . Similarly, IS component  182  is sufficiently transmissive of XTcc light that X light formed with XTcc light and any ARis light temporarily leaves IDVC portion  138 . 
     NA layer  204  can include a programmable reflection-adjusting layer (not separately shown), typically separated from assembly  202  by insulating material, for being electrically programmed subsequent to manufacture of OI structure  200  for adjusting colors A and X. “RA” hereafter means reflection-adjusting. The RA layer is preferably clear transparent prior to programming. The programming causes the RA layer to become tinted transparent or more tinted transparent if it originally was tinted transparent. ARna light is thereby adjusted. XRna light is also adjusted, typically in a way corresponding to the ARna adjustment. As a result, colors A and X are adjusted respectively from an initial principal color A i  and an initial changed color X i  prior to programming to a final principal color A f  and a final changed color X f  subsequent to programming. 
     The programming of the RA layer can be variously done. In one programming technique, a temporary blanket conductive programming layer is deployed on SF zone  112  prior to programming. In another programming technique, OI structure  200  includes a permanent blanket conductive programming layer, typically constituted with part of NA layer  204 , lying between zone  112  and the RA layer. In both techniques, a programming voltage is applied between the programming layer and NE structure  224  sufficiently long to cause the RA layer to change to a desired tinted transparency. The programming layer, if a temporary one, is usually removed from zone  112 . The tinting adjustment can be caused by introduction of RA ions into the RA layer. If the NE layer is patterned, the RA material to the sides of the patterned NE layer usually undergoes the same tinting adjustment as the RA material between the programming layer and the NE layer. 
     Alternatively, core layer  222  can include a programmable RA layer lying along NE structure  224  and having the preceding transparency characteristics. The core RA layer is programmed to a desired tinted transparency by applying a programming voltage between the NE and FE layers for a suitable time period. Introduction of RA ions into the core RA layer can cause the tinting adjustment. If the NE or FE layer is patterned, the RA material to the sides of the patterned NE or FE layer usually undergoes the same tinting adjustment as the RA material between the NE and FE layers. The magnitude of the programming voltage is usually much greater than the magnitudes of control values V nfN  and V nfC . Regardless of whether the RA layer is located in NA layer  204  or structure  224 , the programming voltage can be a selected one of plural different programming values for causing final principal color λ f  to be a corresponding one of like plural different specific final principal colors and for causing final changed color X f  to be a corresponding one of like plural different specific final changed colors. 
     The NE layer transmits at least 40% of incident light across at least part of the visible spectrum and consists of conductive material or/and resistive material whose resistivity is, for example, 10-100 ohm-cm at 300° K. This conductive or/and resistive material is termed transparent conductive material since the resistivity of the resistive material, when present, is close to the upper limit, 10 ohm-cm at 300° K, of the resistivity for conductive material. “TCM” hereafter means transparent conductive material. The FE layer is similarly formed with TCM if visible light is intended to pass fully through one or more thickness locations of core layer  222  at certain times. 
     In situations where a thin layer of a TCM transmits at least 40% of incident light across part, but not all, of the visible spectrum, the selection of colors of light to be transmitted by the thin layer is limited to the part of the visible spectrum across which the layer transmits at least 40% of incident light. The part of the visible spectrum across which a thin layer of a TCM transmits at least 40% of incident light may be single portion continuous in wavelength or a plurality of portions separated by portions in which the thin layer transmits less than 40% of incident light. The transmissivity of incident visible light of a thin layer of the TCM across part, preferably all, of the visible spectrum is usually at least 50%, preferably at least 60%, more preferably at least 80%, even more preferably at least 90%, yet further preferably at least 95%. 
     The thicknesses of a TCM layer meeting the preceding transmissivity criteria is typically 0.1-0.2 μm but can be more or less. The layer thickness can generally be controlled. However, the layer thickness is sometimes determined by the characteristics of the TCM. For instance, the thickness of graphene when used as the TCM is largely the diameter of a carbon atom because graphene consists of a single layer of hexagonally arranged carbon atoms. The transmissivity normally increases with increasing resistivity and vice versa. In particular, decreasing the TCM layer thickness (when controllable) typically causes the transmissivity and resistivity of the TCM layer to increase and vice versa. 
     The transmissivity and resistivity of a TCM layer often depend on how it is fabricated. All of the materials identified below as TCM candidates meet the preceding TCM transmissivity and resistivity criteria for at least one set of TCM manufacturing conditions. If the transmissivity is too low, the transmissivity can generally be increased at the cost of increasing the resistivity by appropriately adjusting the manufacturing conditions or/and reducing the TCM layer thickness (when controllable). If the resistivity is too high, the resistivity can generally be reduced at the cost of reducing the transmissivity by appropriately adjusting the manufacturing conditions or/and increasing the TCM layer thickness (when controllable). 
     Many TCM candidates are transparent conductive oxides generally classified as (i) n-type meaning that majority conduction is by electrons or (ii) p-type meaning that majority conduction is by holes. TCO hereafter means transparent conductive oxide. N-type TCOs are generally much more conductive than p-type TCOs. In particular, the resistivities of n-type TCOs are often several factors of 10 below 1 ohm-cm at 300° K whereas the resistivities of p-type TCOs are commonly 1-10 ohm-cm at 300° K. 
     TCOs include undoped (essentially pure) metallic oxides and doped metallic oxides. In using a dopant metal to convert an undoped TCO containing one or more primary metals into a doped TCO, a dopant metal atom may replace a primary metal atom. Alternatively or additionally, a dopant metal atom may be added to the undoped TCO. The molar amount of dopant metal in a doped TCO is usually considerably less than the molar amount of primary metal in the TCO. If the molar amount of “dopant” metal approaches the molar amount of primary metal, the TCO is often described below as a mixture of oxides of the constituent metals. In some situations, a TCM candidate containing multiple metals is identified below both as a doped TCO and as a mixture of oxides of the metals. 
     Stoichiometric chemical names and/or stoichiometric chemical formulas are generally used below to identify TCM candidates. However, many TCM candidates, especially undoped TCOs, are insulators or semiconductors in their pure stoichiometric formulations. Conductivity sufficiently high for those materials to be TCMs arises from defects in the materials or/and TCM formulations that are somewhat non-stoichiometric. N-type (electron) conductivity sufficiently high to enable an undoped TCO to be an n-type TCM commonly arises when the molar amount of oxygen in the TCO is somewhat below the stoichiometric oxygen amount (oxygen vacancy) or, equivalently, the molar amount of metal in the TCO is somewhat above the stoichiometric metal amount. Similarly, p-type (hole) conductivity sufficiently high to enable an undoped TCO to be a p-type TCM commonly arises when the molar amount of oxygen in the TCO is somewhat above the stoichiometric oxygen amount (oxygen excess) or, equivalently, the molar amount of metal in the TCO is somewhat below the stoichiometric metal amount. 
     In light of the preceding chemical considerations, identifications of TCM candidates by their stoichiometric chemical names and/or stoichiometric chemical formulas here implicitly include formulations that are somewhat non-stoichiometric. More particularly, identification of an undoped n-type TCO by its stoichiometric chemical name or/and its stoichiometric chemical formula includes formulations in which the molar amount of oxygen in the TCO is somewhat below the stoichiometric amount. The same applies to a TCO in which the molar amount of oxygen in the TCO is somewhat below the stoichiometric oxygen amount and in which the TCO includes dopant such that the TCO still conducts n-type. Identification of a p-type TCO, doped or undoped, by its stoichiometric chemical name or/and its stoichiometric chemical formula similarly includes formulations in which the molar amount of oxygen in the TCO is somewhat above the stoichiometric amount. 
     Situations arise in which the molar amount of oxygen in a TCO is somewhat below the stoichiometric amount and in which the TCO includes dopant at a sufficiently high content that the TCO conducts p-type instead of n-type. Identification of such a p-type doped TCO by its stoichiometric chemical name or/and its stoichiometric chemical formula, includes formulations in which the molar amount of oxygen in the TCO is somewhat below the stoichiometric amount. Situations can also arise in which the molar amount of oxygen in a TCO is somewhat above the stoichiometric amount and in which the TCO includes dopant at a sufficiently high content that the TCO conducts n-type instead of p-type. Identification of such an n-type doped TCO by its stoichiometric chemical name or/and its stoichiometric chemical formula includes formulations in which the molar amount of oxygen in the TCO is somewhat above the stoichiometric amount. 
     The following conventions are employed in presenting TCM candidates. Alternative chemical names for some TCM candidates are presented in brackets after their IUPAC names. The name of a TCM candidate consisting essentially of a mixture of two or more compounds is presented as the names of the compounds with a dash separating the names of each pair of constituent compounds. The name of a TCM candidate containing dopant is presented as the name of the undoped compound followed by a colon and the name of the dopant. When the dopant consists of two or more different materials, a dash separates each pair of dopants. Many TCM candidates are placed in sets having certain characteristics in common. In some situations, a TCM candidate has the characteristics for multiple TCM sets. The TCM candidate then generally appears in each appropriate TCM set. 
     The formula for a TCM candidate consisting of an indefinite number of repeating units is generally given as the repeating unit followed by the subscript “n”, e.g., C n  for a carbon TCM. When a TCM candidate contains two or more constituents each formed with an indefinite number of repeating units, each constituent&#39;s portion of the formula is generally given as that constituent&#39;s repeating unit followed by a subscript consisting of “n” and a sequentially increasing number beginning with “1”, e.g. C n1 —(CO 6 H 4 O 2 S) n2  for graphene-poly(3,4-ethyldioxythiophene). 
     Preferred TCM candidates are graphene-containing materials because they generally provide high transmissivity in the visible spectrum, relatively high conductivity, high shock resistance, and high mechanical strength. In addition to graphene C n  itself, graphene-containing TCM candidates include bilayer graphene C n , few-layer graphene C n , graphene foam C n , graphene-graphite C n1 -C n2 , graphene-carbon nanotubes C n1 -C n2 , few-layer graphene-carbon nanotubes C n1 -C n2 , graphene-gold C n —Au, few-layer graphene-gold C n —Au, few-layer graphene-iron trichloride C n —FeCl 3 , graphene-diindium trioxide [graphene-indium oxide] C n —In 2 O 3 , graphene-poly(3,4-ethyldioxythiophene) C n —(CO 6 H 4 O 2 S) n2 , graphene-silver nanowires C n —Ag, and dopant-containing materials boron-doped graphene C n :B (p-type), gold trichloride-doped graphene C n :AuCl 3 , gold-doped graphene C n :Au, gold-doped few-layer graphene C n :Au, graphene-doped silicon dioxide SiO 2 :C n , nitric acid-doped graphene C n :HNO 3  (p-type), nitrogen-doped graphene C n :N (n-type), tetracyanoquinodimethane-doped graphene C n :(NC) 2 CC 6 H 4 C(CN) 2  (p-type), graphene-doped carbon nanotubes C n1 :C n2 , and graphene-doped poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (C 6 H 4 O 2 S) n1 —(C 8 H 8 I 3 S) n2 :C n . 
     Highly desirable TCM candidates are carbon-nanotube-containing materials because they generally provide high transmissivity in the visible spectrum, relatively high conductivity, high shock resistance, and high mechanical strength. In addition to carbon nanotubes C n  itself, carbon-nanotube-containing TCM candidates include carbon nanotubes-gold C n —Au and nitric acid-thionyl chloride-doped carbon nanotubes C n :HNO 3 —SOC 2  (p-type) plus graphene-carbon nanotubes, few-layer graphene-carbon nanotubes, and graphene-doped carbon nanotubes also in the graphene-containing TCM candidates. 
     Certain organic materials, including materials formed with both organic and non-organic constituents, can serve as the TCM. Although organic TCM candidates generally have considerably higher resistivities than graphene and carbon nanotubes, some transparent organic materials provide relatively high shock resistance and relatively high mechanical strength. Organic TCM candidates of this type include poly(3,4-ethylenedioxythiophene) (C 6 H 4 O 2 S) n  termed PEDOT, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (C 6 H 4 O 2 S) n1 —(C 8 H 8 O 3 S) n2  termed PEDOT-PSS, and methanol-doped poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (C 6 H 4 O 2 S) n1 —(C 8 H 803 S) n2 :CH 3 OH, i.e., methanol-doped PEDOT-PSS, plus graphene-poly(3,4-ethyldioxythiophene), graphene-doped poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), and tetracyanoquinodimethane-doped graphene also in the graphene-containing TCM candidates. Each organic TCM candidate is a polymer or a polymer-containing material. 
     The preceding graphene-containing, carbon-nanotube-containing, and organic TCM candidates constitute sets of a larger set of carbon-containing TCM candidates. Subject to excluding graphene-diindium trioxide, nitric acid-thionyl chloride-doped carbon nanotubes, graphene-doped silicon dioxide, and nitric acid-doped graphene because they all contain oxides, the set of carbon-containing TCM candidates are part of an even larger set of transparent non-oxide TCM candidates that includes a set of halide-containing TCM candidates, a set of metal sulfide-containing TCM candidates, a set of metal nitride-containing TCM candidates, and a set of metal nanowire-containing TCM candidates. In addition to few-layer graphene-iron trichloride and gold trichloride-doped graphene also in the carbon-containing TCM candidates, halide-containing non-oxide TCM candidates include p-type copper-containing halides barium copper selenium fluoride BaCuSeF, barium copper tellurium fluoride BaCuTeF, and copper iodide CuI. 
     Metal sulfide-containing non-oxide TCM candidates include barium dicopper disulfide BaCu 2 S 2  (p-type), copper aluminum disulfide CuAIS 2  (p-type), and dopant-containing materials aluminum-doped zinc sulfide ZnS:Al and zinc-doped copper aluminum disulfide CuAlS 2 :Zn (p-type). Metal nitride-containing non-oxide TCM candidates include gallium nitride GaN and titanium nitride TiN. Metal nanowire-containing non-oxide TCM candidates include copper nanowires Cu, gold nanowires Au, and silver nanowires Ag plus graphene-silver nanowires also in the graphene-containing TCM candidates. 
     Undoped n-type TCO candidates for the TCM include cadmium oxide CdO, cadmium oxide-diindium trioxide [cadmium-indium oxide] CdO—In 2 O 3 , cadmium oxide-diindium trioxide-tin dioxide [cadmium-indium-tin oxide] CdO—In 2 O 3 —SnO 2  [Cd—In—S n —O], cadmium oxide-tin dioxide [cadmium-tin oxide] CdO—SnO 2  [Cd—S n —O], cadmium tin trioxide CdSnO 3 , dicobalt trioxide-nickel oxide [cobalt-nickel oxide] Co 2 O 3 —NiO, digallium trioxide [gallium oxide] Ga 2 O 3 , digallium trioxide-tin dioxide [gallium-tin oxide] Ga 2 O 3 —SnO 2 , diindium trioxide [indium oxide] In 2 O 3 , diindium trioxide-digallium trioxide [indium gallium oxide] In 2 O 3 -Ga 2 O 3 , diindium trioxide-tin dioxide [indium-tin oxide] In 2 O 3 —SnO 2 , ditantalum oxide Ta 2 O, dizinc diindium pentoxide Zn 2 In 2 O 5 , dodecacalcium decaluminum tetrasilicon pentatricontoxide Ca 12 Al 10 Si 4 O 35 , digallium trioxide-diindium trioxide-tin dioxide (gallium-indium-tin oxide] Ga 2 O 3 —In 2 O 3 —SnO 2  [Ga—In—S n —O], digallium trioxide-diindium trioxide-zinc oxide [gallium-indium-zinc oxide] Ga 2 O 3 —In 2 O 3 —ZnO [Ga—In—Zn—O], germanium dioxide-zinc oxide-diindium trioxide [germanium-zinc-indium oxide] GeO 2 —ZnO—In 2 O 3 [Ge—Zn—In—O], indium gallium trioxide InGaO 3 , iridium dioxide IrO 2 , lead dioxide PbO 2 , magnesium indium gallium tetroxide MglnGaO 4 , ruthenium dioxide RuO 2 , strontium germanium trioxide SrGeO 3 , tetrazinc diindium heptoxide Zn 4 In 2 O 7 , tetrindium tritin dodecaoxide In 4 S n3 O 12 , tin dioxide SnO 2 , tricadmium tellurium hexoxide Cd 3 TeO 6 , trizinc diindium hexoxide Zn 3 In 2 O 6 , zinc indium aluminum tetroxide ZnlnAlO 4 , zinc indium gallium tetroxide ZnInGaO 4 , zinc oxide ZnO, zinc oxide-diindium trioxide [zinc-indium oxide] ZnO—In 2 O 3  [Zn—In—O], zinc oxide-indium gallium trioxide ZnO—InGaO 3 , zinc oxide-diindium trioxide-tin dioxide [zinc-indium-tin oxide] ZnO—In 2 O 3 —SnO 2  [Zn—In—S n —O], zinc oxide-magnesium oxide [zinc-magnesium oxide] ZnO—MgO [Zn—Mg—O], and zinc tin trioxide ZnSnO 3 . Undoped n-type TCO TCM candidates further include spinel-structured materials cadmium digallium tetroxide CdGa 2 O 4 , cadmium diindium tetroxide CdIn 2 O 4 , dicadmium tin tetroxide Cd 2 SnO 4 , dizinc tin tetroxide Zn 2 SnO 4 , magnesium diindium tetroxide MgIn 2 O 4 , and zinc digallium tetroxide ZnGa 2 O 4 . 
     A first set of doped n-type TCO TCM candidates consists of zinc oxide singly doped with certain elements including aluminum, arsenic, boron, cadmium, chlorine, cobalt, copper, fluorine, gallium, germanium, hafnium, hydrogen, indium, iron, lithium, manganese, molybdenum, nickel, niobium, nitrogen, phosphorus, scandium, silicon, silver, tantalum, terbium, tin, titanium, tungsten, vanadium, yttrium, and zirconium. A second set of doped n-type TCO TCM candidates consists of zinc oxide codoped with two or more of the preceding elements. Specific n-type dopant combinations for zinc oxide include aluminum-boron, aluminum-fluorine, aluminum-nitrogen, boron-fluorine, gallium-aluminum, indium-aluminum, indium-fluorine, scandium-aluminum, silver-nitrogen, titanium-aluminum, tungsten-hydrogen, tungsten-indium, tungsten-manganese, yttrium-aluminum, and zirconium-aluminum. 
     A third set of doped n-type TCO TCM candidates consists of tin dioxide singly doped with certain elements including aluminum, antimony, arsenic, boron, cadmium, chlorine, cobalt, copper, fluorine, gallium, indium, iron, lithium, manganese, molybdenum, niobium, silver, tantalum, tungsten, zinc, and zirconium. Most of the tin dioxide dopants are zinc oxide dopants. A fourth set of doped n-type TCO TCM candidates consists of tin dioxide codoped with two or more of the preceding elements and hafnium. Specific n-type dopant combinations for tin dioxide include hafnium-antimony and indium-gallium. 
     A fifth set of doped n-type TCO TCM candidates consists of diindium trioxide singly doped with certain elements including fluorine, gallium, germanium, hafnium, iodine, magnesium, molybdenum, niobium, tantalum, tin, titanium, tungsten, zinc, and zirconium. Most of the indium oxide dopants are zinc oxide dopants. A sixth set of doped n-type TCO TCM candidates consists of diindium trioxide codoped with two or more of the preceding elements and cadmium. Specific n-type dopant combinations for diindium trioxide include cadmium-tin, magnesium-tin, and zinc-tin. 
     A seventh set of doped n-type TCO TCM candidates consists of cadmium oxide singly doped with certain elements including aluminum, chromium, copper, fluorine, gadolinium, gallium, germanium, hydrogen, indium, iron, molybdenum, samarium, scandium, tin, titanium, yttrium, and zinc. Most of the cadmium oxide dopants are zinc oxide dopants. An eighth set of doped n-type TCO TCM candidates consists of indium gallium trioxide singly doped with certain elements including germanium and tin. A ninth set of doped n-type TCO TCM candidates consists of barium tin trioxide BaSnO 3  singly doped with certain elements including antimony and lanthanum. A tenth set of doped n-type TCO TCM candidates consists of strontium tin trioxide SrTiO 3  singly doped with certain elements including antimony, lanthanum, and niobium. An eleventh set of doped n-type TCO TCM candidates consists of titanium dioxide TiO 2  singly doped with certain elements including cobalt, niobium, and tantalum. 
     A twelfth set of doped n-type TCO TCM candidates consists of zinc oxide-diindium trioxide singly doped with certain elements including aluminum, gallium, germanium, and tin. A thirteenth set of doped n-type TCO TCM candidates consists of zinc oxide-magnesium oxide singly doped with certain elements including aluminum, gallium, indium, and nitrogen. Further doped n-type TCO TCM candidates include antimony-doped strontium tin trioxide SrSnO 3 :Sb, bismuth-doped lead dioxide PbO 2 :Bi, niobium-doped calcium titanium trioxide CaTiO 3 :Nb, tin-doped iron copper dioxide FeCuO 2 :Sn, yttrium-doped cadmium diantimony hexoxide CdSb 2 O 6 :Y, gadolinium-cerium-doped cadmium oxide CdO:Gd—Ce, neodymium-niobium-doped strontium titanium trioxide SrTiO 3 :Nd—Nb, and hydrogen-doped ultraviolet-irradiated dodecacalcium heptaluminum tritricontoxide Ca 12 A17033:H-UV [12CaO.7Al 2 O 3 :H-UV]. 
     Undoped p-type TCO candidates for the TCM include disilver oxide Ag 2 O, iridium dioxide, lanthanum copper selenium oxide LaCuSeO, nickel oxide NiO, ruthenium dioxide, silver oxide AgO, tristrontium discandium dicopper disulfur pentoxide [dicopper disulfide-tristrontium discandium pentoxide] Sr 3 Sc 2 Cu 2 S 2 O 5  [Cu 2 S 2 —Sr 3 Sc 2 O 5 ], dicobalt trioxide-nickel oxide, digallium trioxide-tin dioxide, zinc oxide-beryllium oxide ZnO—BeO, and zinc oxide-magnesium oxide, some of which are undoped n-type TCO TCM candidates. 
     Undoped p-type TCO TCM candidates include certain copper-containing and silver-containing delafossite-structured materials having the general formula MaMbO 3  where the valence of metal Ma is +1 and the valence of metal Mb is +3, Ma appearing after Mb when Ma is more electronegative than Mb. The undoped copper-containing delafossite-structured materials include chromium copper dioxide CrCuO 2 , cobalt copper dioxide CoCuO 2 , copper aluminum dioxide CuAlO 2 , copper boron dioxide CuBO 2 , copper gallium dioxide CuGaO 2 , copper indium dioxide CulnO 2 , iron copper dioxide FeCuO 2 , scandium copper dioxide ScCuO 2 , and yttrium copper dioxide YCuO 2 . The undoped silver-containing delafossite-structured materials include cobalt silver dioxide CoAgO 2 , scandium silver dioxide ScAgO 2 , silver aluminum dioxide AgAlO 2 , and silver gallium dioxide AgGaO 2 . 
     Other undoped p-type TCO TCM candidates include certain copper-containing dumbbell-octahedral-structured materials having the general formula McCu 2 O 2  where the valence of metal Mc is +2. The undoped copper-containing dumbbell-octahedral-structured materials include barium dicopper dioxide BaCu 2 O 2 , calcium dicopper dioxide CaCu 2 O 2 , magnesium dicopper dioxide MgCu 2 O 2 , and strontium dicopper dioxide SrCu 2 O 2 . Spinel-structured materials dicobalt nickel tetroxide Co 2 NiO 4 , dicobalt zinc tetroxide Co 2 ZnO 4 , diiridium zinc tetroxide Ir 2 ZnO 4 , and dirhenium zinc tetroxide Rh 2 ZnO 4  are undoped p-type TCO TCM candidates. 
     A first set of doped p-type TCO TCM candidates consists of zinc oxide singly doped with certain elements including antimony, arsenic, bismuth, carbon, cobalt, copper, indium, lithium, manganese, nitrogen, phosphorus, potassium, sodium, and silver. A second set of doped p-type TCO TCM candidates consists of zinc oxide codoped with two or more of the preceding elements and aluminum, boron, copper, gallium, tantalum, and zirconium. Specific p-type dopant combinations for zinc oxide include aluminum-arsenic, copper-aluminum, and nitrogen-containing dopant combinations aluminum-nitrogen, boron-nitrogen, gallium-nitrogen, indium-nitrogen, lithium-nitrogen, silver-nitrogen, tantalum-nitrogen, and zirconium-nitrogen. 
     A third set of doped p-type TCO TCM candidates consists of tin dioxide singly doped with certain elements including antimony, cobalt, gallium, indium, lithium, and zinc. A fourth set of doped p-type TCO TCM candidates consists of diindium trioxide singly doped with certain elements including silver and zinc. A fifth set of doped p-type TCO TCM candidates consists of nickel oxide singly doped with certain elements including copper and lithium. 
     A sixth set of doped p-type TCO TCM candidates consists of zinc oxide-magnesium oxide singly doped with certain elements including nitrogen and potassium. Doped p-type TCO TCM candidates additionally include aluminum-nitrogen-doped zinc oxide-magnesium oxide ZnO—MgO:Al—N, indium-doped molybdenum trioxide MoOs:In, indium-gallium-doped tin dioxide SnO 2 :In—Ga, magnesium-doped lanthanum copper selenium oxide LaCuSeO:Mg, magnesium-nitrogen-doped dichromium trioxide [magnesium-nitrogen-doped chromium oxide] Cr 2 O 3 :Mg—N, silver-doped dicopper oxide Cu 2 O:Ag, and tin-doped diantimony tetroxide Sb 2 O 4 :Sn. Some of the doped p-type TCO TCM candidates are doped n-type TCO TCM candidates. 
     Doped p-type TCO TCM candidates further include certain copper-containing delafossite-structured materials having the general formula CuMbO 2 :Md where the valence of metal Mb is +3, Cu appearing after Mb when Cu is more electronegative than Mb, and Md is a dopant, usually a metal. Doped copper-containing delafossite-structured materials include calcium-doped copper indium dioxide CulnO 2 :C a , calcium-doped yttrium copper dioxide YCuO 2 :C a , iron-doped copper gallium dioxide CuGaO 2 :Fe, magnesium-doped chromium copper dioxide CrCuO 2 :Mg, magnesium-doped copper aluminum dioxide CuAlO 2 :Mg, magnesium-doped iron copper dioxide FeCuO 2 :Mg, magnesium-doped scandium copper dioxide ScCuO 2 :Mg, oxygen-doped scandium copper dioxide ScCuO 2 :O, and tin-antimony-doped nickel copper dioxide NiCuO 2 :S n —Sb. Other doped p-type TCO TCM candidates include certain copper-containing dumbbell-octahedral-structured materials McCu 2 O 2  where the valence of metal Mc is +2. Doped copper-containing dumbbell-octahedral-structured materials include barium-doped strontium dicopper dioxide SrCu 2 O 2 :Ba, calcium-doped strontium dicopper dioxide SrCu 2 O 2 :C a , and potassium-doped strontium dicopper dioxide SrCu 2 O 2 :K. 
     Reflection-Based Embodiments of Color-Change Component with Electrode Assembly 
     CC component  184  in OI structure  200  can be embodied in various ways. Four general embodiments of component  184  are based on changes in light reflection including light scattering. These four embodiments are termed the mid-reflection, mixed-reflection RT, mixed-reflection RN, and deep-reflection embodiments. None of these embodiments usually employs significant light emission. 
     The following preliminary specifications apply to the four embodiments. Substructure-reflected ARsb or XRsb light is absent. IS segment  192  reflects ARis light during the changed state if IS component  182  reflects ARis light during the normal state. XRna and XRne light respectively reflected by NA segment  214  and NE segment  234  during the changed state are respectively the same as ARna and ARne light respectively reflected by NA layer  204  and NE structure  224  during the normal state. For an embodiment variation in which XRna light differs significantly from ARna light and/or XRne light differs significantly from ARne light, XRna and/or XRne light are to be respectively substituted for ARna and/or ARne light in the following material describing the changed-state operation. Some reflected light invariably leaves VC region  106  during the normal state and IDVC portion  138  during the changed state. 
     The mid-reflection embodiment utilizes normal ARab light reflection and temporary XRab light reflection or, more specifically, normal ARne/ARcl/ARfe light reflection and temporary ARne/XRcl/XRfe light reflection respectively due mostly to ARcl/ARfe light reflection and XRcl/XRfe light reflection. FA layer  206 , if present, is usually not involved in color changing in the mid-reflection embodiment. There is largely no ARfa or XRfa light, and thus largely no total ATfa or XTfa light, here. 
     During the normal state, the mid-reflection embodiment operates as follows. Core layer  222  normally reflects ARcl light or/and FE structure  226  normally reflects ARfe light that passes through layer  222 . ARcl or ARfe light, usually ARcl light, is a majority component of A light. Total ATcl light consists mostly, usually nearly entirely, of normally reflected ARcl light and any normally reflected ARfe light passing through layer  222 , typically mostly ARcl light, and is a majority component of A light. Total ATab light consists mostly, usually nearly entirely, of ARab light formed with ARcl light passing through NE structure  224 , any ARne light reflected by it, and any ARfe light passing through it, likewise typically mostly ARcl light, and is also a majority component of A light. 
     Total ATcc light consists mostly, usually nearly entirely, of ARcl light passing through NA layer  204 , any ARna light reflected by it, and any ARne and ARfe light passing through it, again typically mostly ARcl light. Including any ARis light reflected by IS component  182 , A light is formed with ARcl light and any ARis, ARna, ARne, and ARfe light normally leaving component  182  and thus VC region  106 . 
     During the changed state, core segment  232  responds to the general CC control signal applied between at least oppositely situated parts of electrode segments  234  and  236  by temporarily reflecting XRcl light or/and allowing XRfe light temporarily reflected by FE segment  236  to pass through core segment  232 . XRcl or XRfe light, usually XRcl light, is a majority component of X light. Total XTcl light consists mostly, usually nearly entirely, of temporarily reflected XRcl light and any temporarily reflected XRfe light passing through segment  232 , typically mostly XRcl light, and is a majority component of X light. Total XTab light consists mostly, usually nearly entirely, of XRab light formed with XRcl light passing through NE segment  234 , any ARne light reflected by it, and any XRfe light passing through it, likewise typically mostly XRcl light, and is also a majority component of X light. 
     Total XTcc light consists mostly, usually nearly entirely, of XRcl light passing through NA segment  214 , any ARna light reflected by it, and any ARne and XRfe light passing through it, again typically mostly XRcl light. Including any ARis light reflected by IS segment  192 , X light is formed with XRcl light and any ARis, ARna, ARne, and XRfe light temporarily leaving segment  192  and thus IDVC portion  138 . 
     Assembly  202  in the mid-reflection embodiment of CC component  184  may be embodied with one or more of the following light-processing arrangements: a dipolar suspension arrangement, an electrochromic arrangement, an electrofluidic arrangement, an electrophoretic arrangement (including an electroosmotic arrangement), an electrowetting arrangement, and a photonic crystal arrangement. 
     One implementation of the mid-reflection embodiment employs translation (movement) or/and rotation of a multiplicity (or set) of particles dispersed, usually laterally uniformly, in a supporting medium in core layer  222  for changing the reflection characteristics of core segment  232 . The particles, often titanium dioxide, are normally distributed or/and oriented in the medium so as to cause layer  222  to normally reflect ARcl light such that total ATcl light formed with the ARcl light and any FE-structure-reflected ARfe light passing through layer  222  is at least a majority component of A light. Segment  232  contains a submultiplicity (or subset) of the particles. Responsive to the CC control signal, the particles in segment  232  translate or/and rotate for enabling it to temporarily reflect XRcl light such that total XTcl light formed with the XRcl light and any FE-segment-reflected XRfe light passing through segment  232  is at least a majority component of X light. ARcl and XRcl light are usually respective majority components of A and X light. 
     In one version of the particle translation or/and rotation implementation, the particles are charged particles of largely one color while the supporting medium is a fluid of largely another color. The fluid is typically of a color ARclm quite close to normal reflected core color ARcl and having a majority component of wavelength suitable for color A. The fluid reflects ARclm light while absorbing or/and transmitting, preferably absorbing, other light. The particles are largely of a color XRclm quite close to temporary reflected core color XRcl and having a majority component of wavelength suitable for color X. The particles thereby reflect XRclm light. Color XRclm, usually lighter than color ARclm here, differs materially from color ARclm. 
     Setting control voltage V nf  at normal value V nfN  laterally along core layer  222  causes the particles to be averagely, i.e., on the average, remote from (materially spaced apart from) NE structure  224 . In particular, the particles are normally dispersed throughout the fluid or situated adjacent to (close to or adjoining) FE structure  226 . Because the XRclm-colored particles are normally averagely remote from NE structure  224  and because the ARclm-colored fluid absorbs or/and transmits light other than ARclm light, the large majority of both reflected ARcl light and total ATcl light, formed with ARcl light and any ARfe light, leaving layer  222  is provided by reflection of ARclm light off the fluid. ATcl light leaving layer  222  is largely ARclm light. 
     The particle charging and the V nfC  polarity are chosen such that the particles in core segment  232  translate so as to be adjacent to NE segment  234  when voltage V nf  along core segment  232  goes to changed value V nfC . The large majority of both reflected XRcl light and total XTcl light, formed with XRcl light and any XRfe light, leaving segment  232  is now provided by reflection of XRclm light off the particles in segment  232 . XTcl light leaving segment  232  is largely XRclm light. Since color XRclm differs materially from color ARclm, temporary reflected core color XRcl differs materially from normal reflected core color ARcl. The same result is achieved by reversing both the particle charging and the V nfC  polarity. 
     The fluid can alternatively be of color XRclm. If so, the fluid reflects XRclm light and absorbs or/and transmits, preferably absorbs, other light. The particles are of color ARclm usually now lighter than color XRclm, and either the particle charging or the V nfC  polarity is reversed from that just described. The ARclm-colored particles are normally adjacent to NE structure  224 . The large majority of both reflected ARcl light and total ATcl light is provided by reflection of ARclm light off the particles. ATcl light leaving core layer  222  is again largely ARclm light. 
     Changing voltage V nf  in core segment  232  to value V nfC  causes the particles in segment  232  to translate materially away from NE segment  234  so as to be dispersed throughout the segment of the fluid in core segment  232  or situated adjacent to FE segment  236 . Because the particles in core segment  232  are now averagely remote from NE segment  234  and because the XRclm-colored fluid absorbs non-XRclm light, the large majority of both reflected XRcl light and total XTcl light is provided by reflection of XRclm light off the fluid in core segment  232 . XTcl light leaving segment  232  is again largely XRclm light. With color XRclm differing materially from color ARclm, temporary reflected core color XRcl again differs materially from normal reflected core color ARcl. The same result is achieved by reversing both the particle charging and the V nfC  polarity. 
     The particles in another version of the particle translation or/and rotation implementation consist of two groups of particles of different colors. The supporting medium is a transparent fluid, typically a liquid. The particles in one group are typically largely of color ARclm while the particles in the other group are largely of color XRclm. The particles have characteristics which enable the ARclm-colored particles to translate oppositely to the XRclm-colored particles in the presence of an electric field. The particles can be charged so that the XRclm-colored particles are charged oppositely to the ARclm-colored particles. The charge on each XRclm-colored particle can be of the same magnitude as, or a different magnitude than, the charge on each ARclm-colored particle. 
     The V nfN  polarity and particle characteristics, e.g., particle charging, are chosen such that setting voltage V nf  at normal value V nfN  laterally along core layer  222  causes the ARclm-colored particles to be adjacent to NE structure  224  while the XRclm-colored particles are averagely remote from structure  224 . The large majority of both reflected ARcl light and total ATcl light is normally provided by reflection of ARclm light off the ARclm-colored particles. ATcl light leaving layer  222  is largely ARclm light. 
     Changing voltage V nf  in core segment  232  to value V nfC  at a polarity opposite value V nfN  causes the XRclm-colored particles in segment  232  to translate so as to be adjacent to NE segment  234  while the ARclm-colored particles in core segment  232  translate so as to be averagely remote from segment  234 . The large majority of both reflected XRcl light and total XTcl light is now provided by reflection of XRclm light off the XRclm-colored particles in core segment  232 . XTcl light leaving segment  232  is largely XRclm light. Since color XRclm differs materially from color ARclm, temporary reflected core color XRcl differs materially from normal reflected core color ARcl. 
     The ARclm light reflected by the ARclm-colored particles can be specularly reflected, scattered, or a combination of specularly reflected and scattered. The same applies to the XRclm light reflected by the XRclm-colored particles. The radiosity of the reflected ARclm or XRclm light can be very low such that color ARclm or XRclm is quite dark, sometimes nearly black. If so, the ARclm-colored or XRclm-colored particles absorb the large majority of incident light. 
     Different selections of particle coloring can be made in combination with altering other particle characteristics. In one example, the particles in one group are of color ARclm while the particles in the other group are of a color F1Rc significantly different from colors ARcl and XRcl. The F1Rc-colored particles reflect F1Rc light considerably different from ARcl and XRcl light. The particles have characteristics enabling the ARclm-colored particles to remain adjacent to NE structure  224  in the presence of an electric field that changes polarity while the F1Rc-colored particles translate, to the extent possible, toward or away from structure  224  depending on the field polarity. The F1Rc particles can be charged while the ARclm-colored particles are largely uncharged but have physical properties attracting them to structure  224 . 
     The V nfN  polarity and particle characteristics are chosen such that setting voltage V nf  at normal value V nfN  laterally across core layer  222  causes the ARclm-colored particles to be adjacent to NE structure  224  while the F1Rc-colored particles are averagely remote from structure  224 . The large majority of both reflected ARcl light and total ATcl light is provided by reflection of ARclm light off the ARclm-colored particles. ATcl light leaving layer  222  is again largely ARclm light. 
     The V nfN  polarity and particle characteristics are chosen such that setting voltage V nf  at normal value V nfN  laterally across core layer  222  causes the ARclm-colored particles to be adjacent to NE structure  224  while the F1Rc-colored particles are averagely remote from structure  224 . The large majority of both reflected ARcl light and total ATcl light is provided by reflection of ARclm light off the ARclm-colored particles. ATcl light leaving layer  222  is again largely ARclm light. 
     In a complementary example, the particles in one group are of color XRclm while the particles in the other group are of a color G1Rc significantly different from colors ARcl and XRcl. The G1Rc-colored particles reflect G1Rc light considerably different from ARcl and XRcl light. The particles have characteristics enabling the XRclm-colored particles to remain adjacent to NE structure  224  in the presence of an electric field that changes polarity while the G1Rc-colored particles translate, to the extent possible, toward or away from structure  224  depending on the field polarity. The G1Rc-colored particles can be charged while the XRclm-colored particles are largely uncharged but have physical properties attracting them to structure  224 . 
     The V nfN  polarity and particle characteristics are chosen such that setting voltage V nf  at normal value V nfN  laterally across core layer  222  causes both the XRclm-colored and G1Rc-colored particles to be adjacent to NE structure  224 . The large majority of both reflected ARcl light and total ATcl light is then normally provided by reflection of G1Rc and XRclm light off both the G1Rc-colored and XRclm-colored particles. ATcl light leaving layer  222  consists of a G1Rc and XRclm light. The ATcl combination of G1Rc and XRclm light is chosen to differ materially from XRcl light and, in particular, to have a majority component suitable for color A. 
     Changing voltage V nf  in core segment  232  to value V nfC  of opposite polarity to value V nfN  causes the G1Rc-colored particles to translate materially away from NE segment  234  so as to be averagely remote from segment  234  while the XRclm-colored particles remain adjacent to segment  234 . The large majority of both reflected XRcl light and total XTcl light is provided by reflection of XRclm light off the XRclm-colored particles in core segment  232 . XTcl light leaving segment  232  is again largely XRclm light. Since the ARcl light combination of G1Rc and XRclm light differs materially from XRcl light, temporary core color XRcl differs materially from normal core color ARcl. 
     In a further version of the particle translation or/and rotation implementation, the surface of each particle consists of two portions of different colors. The particles are optically and electrically anisotropic. The optical anisotropicity is achieved by arranging for the outer surface of each particle to consist of one SF portion of color ARclm and another SF portion of color XRclm. The two SF portions are usually of approximately the same area. The particles can be generally spherical with the two SF portions of each particle being hemispherical surfaces. The electrical anisotropicity is achieved by providing the two SF portions of each particle with different zeta potentials. Each particle is usually a dipole with one SF portion negatively charged and the other positively charged. The supporting medium is a solid transparent sheet having cavities in which the particles are respectively located. Each cavity is slightly larger than its particle. The part of each cavity outside its particle is filled with transparent dielectric fluid for enabling each particle to rotate freely in its cavity. 
     Voltage values V nfN  and V nfC  are chosen so that one is positive and the other is negative. If value V nfN  is positive, the ARclm-colored SF portions are negatively charged while the XRclm-colored SF portions are positively charged. The opposite surface-portion charging is used if value V nfN  is positive. Either way, setting voltage V nf  at normal value V nfN  causes the particles to rotate so that their ARclm-colored SF portions face NE structure  224 . The large majority of both reflected ARcl light and total ATcl light is provided by reflection of ARclm light off the ARclm-colored SF portions of the particles. ATcl light leaving core layer  222  is largely ARclm light. 
     Applying the general CC control signal to core segment  232  so that voltage V nf  is at changed value V nfC  across segment  232  causes the particles in it to rotate so that their XRcl-colored SF portions face NE segment  234 . The large majority of both reflected XRcl light and total XTcl light is now provided by reflection of XRclm light off the XRcl-colored SF portions of the particles in core segment  232 . XTcl light leaving segment  232  is largely XRclm light. With color XRclm differing materially from color ARclm, temporary core color XRcl differs materially from normal core color ARcl. 
     During the changed state in all three versions of the particle translation or/and rotation implementation, the particles in the remainder of core layer  222  largely maintain the particle orientations or/and average locations existent during the normal state. The large majority of both reflected light and total light leaving the remainder of layer  222  consists of reflected ARclm light or, in the last-mentioned example of the version using two groups of particles of different colors, a reflected combination of XRclm and G1Rc light identical to that normally present and thereby forming ARcl light. 
     Another implementation of the mid-reflection embodiment of CC component  184  entails changing the absorption characteristics of particles dispersed, usually uniformly, in a supporting medium usually a fluid such as a liquid in which the particles are suspended. In one version, the particles normally absorb much, usually most, of the light striking SF zone  112  so that ATcl light normally leaves layer  222 . The particles in core segment  232  respond to the general CC control signal by scattering much, usually most, of the light striking print area  118 . This causes XTcl light, including XRcl light, to temporarily leave segment  232 . Alternatively, the particles in layer  222  normally scatter much, usually most, of the light striking zone  112  so that ATcl light, including ARcl light, normally leaves layer  222 . The particles in segment  232  respond to the control signal by absorbing much, usually most, of the light striking area  118  for causing XTcl light to temporarily leave segment  232 . 
     The particles in core layer  222  in another version of the absorption-characteristics-changing implementation are elongated dichroic particles normally at largely random orientations with largely no electric field existing across layer  222 . The particles in layer  222  normally absorb much, usually most, of the light striking SF zone  112  so that ATcl light normally leaves layer  222 . Responsive to the general CC control signal, the particles in core segment  232  align generally with an electric field produced across segment  232 . Much, usually most, of the light striking print area  118  is transmitted through segment  232  for causing XTcl light, including reflected XRfe light, to temporarily leave segment  232 . Alternatively, an electric field normally exists across all of layer  222 . The particles in layer  222  align with the electric field for enabling much, usually most, of the light striking zone  112  to be transmitted through layer  222  so that ATcl light, including reflected ARfe light, normally leaves layer  222 . In response to the control signal, the particles in segment  232  become largely randomly oriented for absorbing much, usually most, of the light striking area  118 . XTcl light temporarily leaves segment  232 . 
     Core layer  222  in a further implementation, an example being an electrowetting or electrofluidic arrangement, of the mid-reflection embodiment of CC component  184  employs a liquid whose shape is suitably manipulated to change the layer&#39;s reflection characteristics. The liquid is in a first shape for causing layer  222  to reflect ARcl light such that ATcl light formed with the ARcl light and any FE-structure-reflected ARfe light passing through layer  222  is a majority component of A light. Responsive to the general CC control signal, the liquid in core segment  232  temporarily changes to a second shape materially different from the first shape in segment  232  for causing it to reflect XRcl light such that total XTcl light formed with XRcl light and any FE-segment-reflected XRfe light passes through segment  232  and is a majority component of X light. Exemplary shapes for the liquid are described in U.S. Pat. Nos. 6,917,456 B2, 7,463,398 B2, and 7,508,566 B2, contents incorporated by reference herein. Three major versions of the liquid shape-changing implementation entail arranging for (a) ARcl light to be a majority component of A light with XRcl light being a majority component of X light, (b) ARcl light to be a majority component of A light with XRfe light being a majority component of X light, and (c) ARfe light to be a majority component of A light with XRcl light being a majority component of X light. 
     Turning to the two mixed-reflection embodiments of CC component  184 , each mixed-reflection embodiment utilizes FA layer  206  for reflecting light in achieving color changing. Light striking core layer  222  along NE structure  224  passes through layer  222  to FE structure  226  at selected thickness locations along layer  222  at certain times and is blocked, i.e., reflected or/and absorbed, by layer  222  at other times. Light passing through selected thickness locations of layer  222  then passes through corresponding thickness locations of structure  226  and undergoes substantial reflection at corresponding thickness locations of FA layer  206 . Resultant reflected light passes back through structure  226  and core layer  222 . Assembly  202  functions as a light valve. The difference between the mixed-reflection embodiments is that FA layer  206  reflects light only during the changed state in the mixed-reflection RT embodiment and only in the normal state in the mixed-reflection RN embodiment. 
     The mixed-reflection RT embodiment employs normal ARab light reflection and temporary XRab/XRfa light reflection or, more specifically, normal ARne/ARcl/ARfe light reflection and temporary ARne/XRcl/XRfe/XRfa light reflection respectively due mostly to ARcl/ARfe light reflection and XRfa light reflection. During the normal state, the mixed-reflection RT embodiment operates the same as the mid-reflection embodiment. 
     Core segment  232  in the mixed-reflection RT embodiment responds to the general CC control signal applied between at least oppositely situated parts of electrode segments  234  and  236  during the changed state by allowing a substantial part of light striking print area  118  and passing through IS segment  192 , NA segment  214 , and NE segment  234  to temporarily pass through core segment  232  such that a substantial part of that light passes through FE segment  236 . FA segment  216  temporarily reflects XRfa light, a majority component of X light. Total XTfa light consists mostly, preferably only, of temporarily reflected XRfa light. 
     A substantial part of the XRfa light passes through FE segment  236  and, as also allowed by core segment  232 , passes through it. Total XTcl light consists of XRfa light passing through segment  232 , any XRcl light reflected by it, and any FE-segment-reflected XRfe light passing through it, mostly reflected XRfa light. Total XTab light consists of XRfa light passing through NE segment  234  and any XRab light formed with any ARne light reflected by segment  234  and any XRcl and XRfe light passing through it, likewise mostly XRfa light. Total XTcc light consists of XRfa light passing through NA segment  214 , any ARna light reflected by it, and any ARne, XRcl, and XRfe light passing through it, again mostly XRfa light. Including any ARis light reflected by IS segment  192 , X light is formed with XRfa light and any ARis, ARna, ARne, XRcl, and XRfe light temporarily leaving segment  192  and thus IDVC portion  138 . 
     The mixed-reflection RN embodiment employs normal ARab/ARfa light reflection and temporary XRab light reflection or, more specifically, normal ARne/ARcl/ARfe/ARfa light reflection and temporary ARne/XRcl/XRfe light reflection respectively due mostly to ARfa light reflection and XRcl/XRfe light reflection. During the normal state, core layer  222  allows light striking SF zone  112  and passing through IS component  182 , NA layer  204 , and NE structure  224  to normally pass through core layer  222  such that a substantial part of that light normally passes through FE structure  226 . FA layer  206  reflects ARfa light, a majority component of A light. Total ATfa light consists mostly, preferably only, of normally reflected ARfa light. 
     A substantial part of the ARfa light passes through FE structure  226  and, as also allowed by core layer  222 , passes through it. Total ATcl light consists of ARfa light passing through layer  222 , any ARcl light reflected by it, and any FE-structure-reflected ARfe light passing through it, mostly reflected ARfa light. Total ATab light consists of ARfa light passing through NE structure  224  and any ARab light formed with any ARne light reflected by structure  224  and any ARcl and ARfe light passing through it, likewise mostly ARfa light. Total ATcc light consists of ARfa light passing through NA layer  204 , any ARna light reflected by it, and any ARne, ARcl, and ARfe light passing through it, again mostly ARfa light. Including any ARis light reflected by IS component  182 , A light is formed with ARfa light and any ARis, ARna, ARne, ARcl, and ARfe light normally leaving component  182  and thus VC region  106 . 
     Core segment  232  in the mixed-reflection RN embodiment responds to the general CC control signal the same as in the mid-reflection embodiment. Accordingly, the mixed-reflection RN embodiment operates the same in the changed state as the mid-reflection embodiment. 
     In one version of each mixed-reflection embodiment of CC component  184 , core layer  222  contains core particles distributed laterally across the layer&#39;s extent and switchable between light-transmissive and light-blocking states. NA layer  204  may be present or absent. FA layer  206  contains a light reflector extending along, and generally parallel to, FE structure  226 . The light reflector may be a specular (mirror-like) reflector or a diffuse reflector that reflectively scatters light. 
     The core particles are usually dimensionally anisotropic, each particle typically shaped generally like a rod or a sheet. For a rod-shaped core particle having (a) a maximum dimension, termed the long dimension, (b) a shorter dimension which reaches a maximum value, termed the first short dimension, in a plane perpendicular to the long dimension, and (c) another shorter dimension which extends perpendicular to the other two dimensions and which reaches a maximum value, termed the second short dimension, no greater than the first short dimension, the long dimension is at least twice, preferably at least four times, more preferably at least eight times, the first short dimension. For a sheet-shaped core particle having (a) a maximum dimension, termed the first long dimension, (b) another dimension which reaches a maximum value, termed the second long dimension, no greater than the first long dimension in a plane perpendicular to the first long dimension, and (c) a shorter dimension which reaches a maximum value, termed the short dimension, and which extends perpendicular to the other two dimensions, the first long dimension is at least twice, preferably at least four times, more preferably at least eight times, the short dimension. 
     The core particles in core layer  222  in the mixed-reflection RT version are normally oriented largely randomly relative to electrode structures  224  and  226 . This enables the core particles in layer  222  to absorb or/and scatter light striking it along NE structure  224 . Either way, light striking SF zone  112  and passing through IS component  182  and NA layer  204  so as to strike core layer  222  along structure  224  is normally blocked from passing through layer  222 . Total ATcl light leaving layer  222  consists of any ARcl light reflected by it and any FE-structure-reflected ARfe light passing through it. 
     Applying the general CC control signal to AB segment  212  in the mixed-reflection RT version causes the core particles in core segment  232  to orient themselves generally perpendicular to electrode segments  234  and  236 . In particular, the long dimension of a rod-shaped core particle extends generally perpendicular to segments  234  and  236  while one of the long dimensions of a sheet-shaped core particle extends generally perpendicular to segments  234  and  236  so that the general plane of the sheet-shaped particle is perpendicular to segments  234  and  236 . This orientation enables light striking print area  118  and passing through IS segment  192  and NA segment  214  so as to strike core segment  232  along NE segment  234  to be temporarily transmitted through core segment  232  and reflected by the segment of the light reflector in FA segment  216 . The temporarily reflected XRfa light passes in substantial part back through core segment  232 . Total XTcl light leaving segment  232  consists of XRfa light passing through it, any XRcl light reflected by it, and any FE-segment-reflected XRfe light passing through it. 
     Essentially the reverse occurs in the mixed-reflection RN version. The core particles present in core layer  222  are normally oriented generally perpendicular to electrode structures  224  and  226 . Specifically, the long dimension of a rod-shaped core particle extends generally perpendicular to structures  224  and  226  while one of the long dimensions of a sheet-shaped core particle extends generally perpendicular to structures  224  and  226  so that the general plane of the sheet-shaped particle is perpendicular to structures  224  and  226 . Light striking SF zone  112  and passing through IS component  182  and NA layer  204  so as to strike core layer  222  along NE structure  224  is transmitted through layer  222  and reflected by the light reflector. The normally reflected ARfa light passes in substantial part back through layer  222 . Total ATcl light leaving layer  222  consists of ARfa light passing through it, any ARcl light reflected by it, and any FE-structure-reflected ARfe light passing through it. 
     Applying the general CC control signal to AB segment  212  in the mixed-reflection RN version causes the core particles in core segment  232  to become randomly oriented relative to electrode segments  234  and  236 . Light striking print area  118  and passing through IS segment  192  and NA segment  214  so as to strike core segment  232  along NE segment  234  is largely scattered or/and absorbed by the core particles in core segment  232  and is thereby blocked from passing through segment  232 . Total XTcl light leaving segment  232  consists of any XRcl light reflected by it and any FE-segment-reflected XRfe light passing through it. 
     Core layer  222  consists of liquid-crystal material formed with elongated liquid-crystal molecules that constitute the core particles in another version of the mixed-reflection RT or RN embodiment of CC component  184  where it is a reflective liquid-crystal arrangement, usually polarizer-free. “LC” hereafter means liquid-crystal. The LC molecules, which switch between light-transmissive and light-scattering states, can employ various LC phases such as nematic, smectic, and chiral. The LC material typically has no pre-established twist. For this purpose, the surfaces of electrode structures  224  and  226  along layer  222  are preferably flat rather than grooved. 
     The reflected XRfa or ARfa light in each LC version of the mixed-reflection RT or RN embodiment usually appears along NE structure  224  as a dark color but, depending on the constituency of core layer  222 , can appear along structure  224  as a light color. The dark color can be largely black. The scattered ARcl or XRcl light usually appears along NE structure  224  as a light color but, likewise depending on the constituency of layer  222 , can appear along structure  224  as a dark color. The light color can be white or largely white. 
     In a further version of the mixed-reflection RT or RN embodiment of CC component  184 , core layer  222  is formed with a fluid, typically a liquid, in which dipolar particles constituting the core particles are colloidally suspended. The dipolar particles, usually dichroic, can be elongated rod-like particles or flat sheet-like particles. Each dipole particle has a positively charged end and a negatively charged end. Voltage V nf  across opposite segments of electrode structures  224  and  226  is usually largely zero when the intervening dipole particles are randomly oriented so as to scatter or/and absorb light striking them. Adjusting voltage V nf  across opposite segments of structures  224  and  226  to a non-zero value causes the intervening dipole particles to align generally perpendicular to those two electrode segments with the positively charged end of each intervening dipolar particle closest to the more negative one of the electrode segments and vice versa. 
     Various color combinations are available with the dipolar-particle suspension. Subject to a dark color being produced along NE structure  224  if the dipolar particles in core layer  222  or core segment  232  absorb incident light due to being randomly oriented relative to electrode structures  224  and  226 , the scattered ARcl or XRcl light in each mixed-reflection version can appear along NE structure  224  as a light color, or as a dark color, if the dipolar particles across layer  222  or in segment  232  scatter incident light due to being randomly oriented relative to structures  224  and  226 . The reflected XRfa or ARfa light correspondingly appears along NE structure  224  as a dark color, or as a light color, depending on the characteristics of the light reflector. 
     The deep-reflection embodiment of CC component  184  employs normal ARab/ARfa light reflection and temporary XRab/XRfa light reflection or, more specifically, normal ARne/ARcl/ARfe/ARfa light reflection and temporary ARne/XRcl/XRfe/XRfa light reflection respectively due mostly to ARfa light reflection and XRfa light reflection. Light striking SF zone  112  passes through IS component  182 , NA layer  204 , NE structure  224 , core layer  222 , and FE structure  226 , is reflected by FA layer  206 , and then passes back through subcomponents  226 ,  222 ,  224 , and  182 . Core layer  222  and auxiliary layers  204  and  206  usually impose certain traits, e.g., wavelength-independent traits such as polarization traits, on the light. “WI” hereafter means wavelength-independent. 
     When WI traits are employed, the deep-reflection embodiment operates as follows during the normal state. NA layer  204  typically imposes a WI NA incoming trait on light normally passing from IS component  182  through layer  204  so that the light has the NA incoming trait upon reaching core layer  222 , “NA” again meaning near auxiliary. Layer  222  imposes a WI primary incoming trait on light normally passing from NE structure  224  through layer  222  so that the light has the primary incoming trait upon reaching FA layer  206 . The primary incoming trait usually differs materially from the NA incoming trait. 
     FA layer  206  normally reflects ARfa light, a majority component of A light, so that total ATfa light consists mostly, preferably only, of normally reflected ARfa light. As an adjunct to reflecting ARfa light, layer  206  typically imposes a WI FA trait on ARfa light leaving layer  206  along FE structure  226 , “FA” again meaning far auxiliary. The FA trait is usually applied to light just before and after reflection by layer  206 . The FA trait can be the same as, or significantly different from, the NA incoming trait. 
     The ARfa light passes in substantial part through FE structure  226 . Total ATfe light consists of ARfa light passing through structure  226  and any ARfe light reflected by it, mostly ARfa light having the FA trait. The ATfe light passes in substantial part through core layer  222  and NE structure  224 . In transmitting ATfe light, layer  222  imposes a WI primary outgoing trait on ATfe light passing from FE structure  226  through layer  222  so that the ATfe light has the primary outgoing trait upon reaching NA layer  204 . The primary outgoing and incoming traits are usually the same. Total ATcl light consists of ARfa light passing through core layer  222 , any ARcl light reflected by it, and any ARfe light passing through it, mostly ARfa light having the primary outgoing trait. The ATcl light passes in substantial part through NE structure  224 . Total ATab light consists of ARfa light passing through structure  224  and any ARab light formed with any ARne light reflected by structure  224  and any ARcl and ARfe light passing through it, likewise mostly ARfa light. 
     The ATab light passes in substantial part through NA layer  204  and IS component  182 . If the NA incoming trait is imposed on light passing from component  182  through layer  204 , layer  204  usually imposes a WI NA outgoing trait on ATab light passing from NE structure  224  through layer  204  so that ATab light has the NA outgoing trait upon reaching component  182 . The NA outgoing and incoming traits are usually the same. Total ATcc light consists of ARfa light passing through layer  204 , any ARna light reflected by it, and any ARne, ARcl, and ARfe light passing through it, again mostly ARfa light. Including any ARis light normally reflected by component  182 , A light is formed with ARfa light and any ARis, ARna, ARne, ARcl, and ARfe light normally leaving component  182  and thus VC region  106 . 
     Core segment  232  in the deep-reflection embodiment responds to the general CC control signal applied between at least oppositely situated parts of electrode segments  234  and  236  by causing light passing from NE segment  234  through core segment  232  to be temporarily of a WI changed incoming trait such that the light has the changed incoming trait upon reaching FA segment  216 . More particularly, if NA layer  204  imposes the NA incoming trait on light normally passing from IS component  182  through layer  204 , NA segment  214  imposes the NA incoming trait on light passing from IS segment  192  through segment  214  so that the light has the NA incoming trait upon reaching core segment  232 . Segment  232  then imposes the changed incoming trait on light temporarily passing from NE segment  234  through segment  232  so that the light has the changed incoming trait upon reaching FA segment  216 . The changed incoming trait differs materially from the primary incoming trait. 
     FA segment  216  temporarily reflects XRfa light, a majority component of X light, so that total XTfa light consists mostly, preferably only, of temporarily reflected XRfa light. Although the primary and changed incoming traits are independent of wavelength, the material difference between them is chosen to cause color XRfa to differ materially from color ARfa. More specifically, colors ARfa and XRfa usually have the same wavelength characteristics but differ materially in radiosity so as to differ materially in lightness/darkness and therefore materially in color. Core segment  232  and AB segment  212  function as a light valve in producing the color difference. In the course of reflecting XRfa light, FA segment  216  imposes the FA trait on XRfa light leaving it along FE segment  236  if FA layer  206  imposes the FA trait on ARfa light leaving layer  206  along FE structure  226 . The FA trait is usually applied to light just before and after reflection by FA segment  216 . 
     The XRfa light passes in substantial part through FE segment  236 . Total XTfe light consists of XRfa light passing through segment  236  and any XRfe light reflected by it, mostly XRfa light having the FA trait. The XTfe light passes in substantial part through core segment  232 . In transmitting XTfe light, segment  232  imposes a WI changed outgoing trait on XTfe light passing from FE segment  236  through segment  232  so that the XTfe light has the changed outgoing trait upon reaching NA segment  214 . The changed outgoing trait, usually the same as the changed incoming trait, differs materially from the primary incoming and outgoing traits. Total XTcl light consists of XRfa light passing through core segment  232 , any XRcl light reflected by it, and any XRfe light passing through it, mostly XRfa light now having the changed outgoing trait. Any XRcl light is usually largely ARcl light. The XTcl light passes in substantial part through NA segment  214 . Total XTab light consists of XRfa light passing through NE segment  234  and any XRab light formed with any ARne light reflected by segment  234  and any XRcl and XRfe light passing through it, likewise mostly XRfa light. 
     The XTab light passes in substantial part through NA segment  214  and IS segment  192 . If NA segment  214  imposes the NA incoming trait on light passing from IS segment  192  through NA segment  214 , segment  214  imposes the NA outgoing trait on XTab light passing from NE segment  234  through segment  214  so that XTab light has the NA outgoing trait upon reaching IS segment  192 . Including any ARna light reflected by NA segment  214 , total XTcc light consists of XRfa light passing through segment  214 , any ARna light reflected by it, and any ARne, XRcl, and XRfe light passing through it, again mostly XRfa light. Similarly including any ARis light reflected by IS segment  192 , X light is formed with XRfa light and any ARis, ARna, ARne, XRcl, and XRfe light leaving segment  192  and thus IDVC portion  138 . 
     The deep-reflection embodiment of CC component  184  is typically a reflective LC structure in which core layer  222  consists largely of LC material such as nematic liquid crystal formed with elongated LC particles. FA layer  206  contains a light reflector extending along, and generally parallel to, FE structure  226 . The light reflector, specular or diffuse, is designed to reflect ARfa light during the normal state such that the segment of the light reflector in FA segment  216  reflects XRfa light during the changed state. The reflector is a white-light reflector if one of colors ARfa and XRfa is white. If neither is white, the reflector can be a color reflector or a white-light reflector and a color filter lying between the white-light reflector and structure  226 . 
     NA layer  204  usually contains a near (first) plane polarizer extending along, and generally parallel to, NE structure  224 . If so, FA layer  206  contains a far (second) plane polarizer extending along, and generally parallel to, FE structure  226  so as to extend generally parallel to the near polarizer. The far polarizer is located between structure  226  and the light reflector. 
     Each polarizer has a polarization direction parallel to the plane of that polarizer. “PZ” hereafter means polarization. The PZ direction of the near polarizer is termed the p direction. The direction parallel to the plane of the near polarizer and perpendicular to the p direction is termed the s direction. The PZ direction of the far polarizer is typically perpendicular to, or parallel to, the near polarizer&#39;s PZ direction but can be at a non-zero angle materially different from 90° to the PZ direction. In the following description of the operation of the reflective LC structure, the polarizers have perpendicular PZ directions so that the far polarizer&#39;s PZ direction is the s direction. 
     Relative to the near polarizer, incoming light striking NA layer  204  consists of a p directional component and an s directional component. For each color A or X, the near polarizer transmits a high percentage, usually at least 70%, preferably at least 80%, more preferably at least 90%, even more preferably at least 95%, of the p component and blocks, preferably absorbs, the s component. Light passing through the near polarizer so as to strike assembly  202  is plane polarized in the PZ direction of the near polarizer, i.e., the p direction. The plane polarized light passes in substantial part through the LC material. 
     The elongated particles of the LC material in core layer  222  are normally in an orientation which causes the PZ direction of incoming incident p polarized light to rotate a primary LC amount so that the transmitted light leaving the LC material and striking the far polarizer is plane polarized in a direction materially different from the p direction. The primary LC amount of the PZ direction rotation is usually 45°-90° for which an actual PZ direction rotation of greater than 360° is converted to an effective PZ direction rotation by subtracting 360° one or more times until the resultant rotation value is less than 360°. For each color A or X, the far polarizer transmits a high percentage, usually at least 70%, preferably at least 80%, more preferably at least 90%, even more preferably at least 95%. of incident s polarized light and blocks, preferably absorbs, any other incident light. The radiosity of the s polarized light passing through the far polarizer increases as the effective PZ direction rotation provided by the LC material moves toward 90°. 
     A substantial part of the plane polarized light passing through the far polarizer is normally reflected by the light reflector and passes back through the far polarizer, the LC material, and the near polarizer. The far polarizer blocks, preferably absorbs, any reflected incident light plane polarized in any direction other than the s direction so that reflected light passing through the far polarizer largely forms ARfa light plane polarized in the s direction. The LC material causes reflected incident s polarized ARfa light to undergo a rotation in PZ direction largely equal to the primary LC amount. The near polarizer blocks, preferably absorbs, any reflected incident light plane polarized in largely any direction other than the p direction so that reflected light passing through the near polarizer includes ARfa light plane polarized in the p direction. The radiosity of the reflected p polarized ARfa light passing through the near polarizer increases as the effective PZ direction rotation provided by the LC material moves toward 90°. 
     Core segment  232  responds to the general CC control signal provided during the changed state by causing the LC particles in segment  232  to change to an orientation materially different from their orientation in the normal state such that incoming plane polarized light passing through segment  232  and striking the segment of the far polarizer in segment  216  of FA layer  206  is plane polarized in a materially different direction than incoming plane polarized light passing through core layer  222  and striking the far polarizer during the normal state. The LC-particle orientation change in core segment  232  may entail rotating the PZ direction of plane polarized light passing through segment  232  by a changed LC rotational amount usually less than 45°. If so, the effective PZ direction rotation provided by segment  232  during the changed state is materially different from, usually materially less than, the effective PZ direction rotation provided by layer  222  during the normal state. 
     During the changed state, the far polarizer segment in FA segment  216  transmits a high percentage of incident polarized light plane polarized in the s direction and blocks, preferably absorbs, incident light plane polarized in largely any other direction just as in the normal state. However, the radiosity of the reflected s polarized light temporarily passing through the far polarizer segment in FA segment  216  differs materially from, is usually materially less than, the radiosity of the reflected s polarized light normally passing through the far polarizer because the effective PZ direction rotation, if any, temporarily provided by the LC material in core segment  232  differs materially from, is usually materially less than, the effective PZ direction rotation normally provided by the LC material in core layer  222 . 
     A substantial part of the plane polarized light passing through the far polarizer segment in FA segment  216  during the changed state is reflected by the segment of the light reflector in FA segment  216  and passes back through the far polarizer segment in segment  216 , core segment  232 , and the segment of the near polarizer in NA segment  214 . The far polarizer segment in FA segment  216  blocks, preferably absorbs, any reflected incident light plane polarized in any direction other than the s direction so that reflected light passing through the far polarizer segment in segment  216  largely forms XRfa light plane polarized in the s direction. To the extent that the PZ direction of incoming p polarized XRfa light leaving the near polarizer segment in NA segment  214  temporarily undergoes rotation, the LC material in core segment  232  causes reflected incident s polarized XRfa light to undergo the same rotation in PZ direction. The near polarizer segment in NA segment  214  blocks, preferably absorbs, any reflected incident light plane polarized in any direction other than the p direction so that reflected light passing through the near polarizer segment in NA segment  214  includes XRfa light plane polarized in the p direction. 
     The radiosity of the reflected p plane polarized XRfa light temporarily passing through the near polarizer segment in NA segment  214  differs materially from, is usually materially less than, the radiosity of the reflected p plane polarized ARfa light normally passing through the near polarizer because the radiosity of the reflected s plane polarized XRfa light temporarily passing through the far polarizer segment in FA segment  216  differs materially from, is usually materially less than, the radiosity of the reflected s plane polarized ARfa light normally passing through the far polarizer due to the effective PZ direction rotation, if any, temporarily provided by core segment  232  differing materially from, usually being materially less than, the effective PZ direction rotation normally provided by core layer  222 . Colors ARfa and XRfa normally have the same wavelength characteristics. However, the material difference in radiosity between the resultant reflected p plane polarized XRfa light temporarily leaving NA segment  214  and the resultant reflected p plane polarized ARfa light normally leaving NA layer  204  by itself, or in combination with other reflected light leaving print area  118  during the changed state and SF zone  112  during the normal state enables color X to differ materially from color A. With color XRfa being of materially lower radiosity than color ARfa, color X is materially lighter than color A even though the wavelength characteristics of ARfa and XRfa light are the same. For instance, color X can be pink while color A is red. 
     The WI traits in the deep-reflection embodiment are embodied as follows in the reflective LC structure with the polarizers having perpendicular PZ directions. For the NA incoming and outgoing traits, the near polarizer causes light passing either way through NA layer  204  to be plane polarized in the p direction. For the FA trait, the far polarizer causes light passing either way through the FA layer  206  to be plane polarized in the s direction. For the primary incoming and outgoing traits, the LC material in core layer  222  causes the PZ direction of plane polarized light passing either way through layer  222  during the normal state to rotate the primary LC rotational amount, usually 45°-90°. For the changed incoming and outgoing traits, the segment of the LC material in core segment  232  causes the PZ direction of light passing through segment  232  during the changed state to rotate the changed LC rotational amount, usually less than 45°, if the LC material in segment  232  undergoes any PZ direction rotation during the changed state. 
     When the polarizers in the reflective LC structure have parallel PZ directions with the near polarizer causing light passing either way through NA layer  204  to be plane polarized in the p direction, the actions performed by the far polarizer and the LC material during the normal and changed states are opposite from the actions performed by the far polarizer and the LC material when the polarizers in the reflective LC structure have perpendicular PZ directions. The WI traits in the deep-reflection embodiment are then embodied as follows. For the FA trait, the far polarizer causes light passing either way through FA layer  206  to be plane polarized in the p direction. For the primary incoming and outgoing traits, the LC material in core layer  222  causes the PZ direction of plane polarized light normally passing either way through layer  222  to rotate a primary LC amount, usually less than 45°, if the LC material in layer  222  normally undergoes any PZ direction rotation. For the changed incoming and outgoing traits, the segment of the LC material in core segment  232  causes the PZ direction of light temporarily passing through segment  232  to rotate a changed LC amount, usually 45°-90°. 
     Emission-Based Embodiments of Color-Change Component with Electrode Assembly 
     Six general embodiments of CC component  184  in OI structure  200  are based on changes in light emission. These six embodiments are termed the mid-emission ET, mid-emission EN, mid-emission EN-ET, deep-emission ET, deep-emission EN, and deep-emission EN-ET embodiments. The above-described preliminary specifications for the four CC-component light-reflection embodiments apply to these six CC-component light-emission embodiments. 
     Beginning with the three mid-emission embodiments of CC component  184 , FA layer  206  is not significantly involved in color changing in any of the mid-emission embodiments. There is largely no ARfa, AEfa, XRfa, or XEfa light, and thus largely no ADfa, ATfa, XDfa, or XTfa light, in any of the mid-emission embodiments. The difference between the two single mid-emission embodiments is that core layer  222  emits light only during the changed state in the mid-emission ET embodiment and only during the normal state in the mid-emission EN embodiment. Layer  222  emits light during both states in the mid-emission EN-ET embodiment. 
     The mid-emission ET embodiment utilizes normal ARab light reflection and temporary XEab light emission-XRab light reflection or, more specifically, normal ARne/ARcl/ARfe light reflection and temporary XEcl light emission-ARne/XRcl/XRfe light reflection respectively due mostly to ARcl/ARfe light reflection and XEcl light emission. During the normal state, the mid-emission ET embodiment operates the same as the mixed-reflection RT embodiment and thus the same as the mid-reflection embodiment. 
     During the changed state, core segment  232  in the mid-emission ET embodiment responds to the general CC control signal applied between at least oppositely situated parts of electrode segments  234  and  236  by temporarily emitting XEcl light, usually a majority component of X light. Total XTcl light consists of XEcl light, any XRcl light reflected by segment  232 , and any FE-segment-reflected XRfe light passing through it, usually mostly temporarily emitted XEcl light. Any reflected XRcl light is usually largely ARcl light. Total XTab light consists of XDab light formed with XEcl light passing through NE segment  234 , any ARne light reflected by it, and any XRcl and XRfe light passing through it, likewise usually mostly XEcl light. Total XTcc light consists of XEcl light passing through NA segment  214 , any ARna light reflected by it, and any ARne, XRcl, and XRfe light passing through it, again usually mostly XEcl light. Including any ARis light reflected by IS segment  192 , X light is formed with XEcl light and any ARis, ARna, ARne, XRcl and XRfe light leaving segment  192  and thus IDVC portion  138 . 
     The mid-emission EN embodiment utilizes normal AEab light emission-ARab light reflection and temporary XRab light reflection or, more specifically, normal AEcl light emission-ARne/ARcl/ARfe light reflection and temporary ARne/XRcl/XRfe light reflection respectively due mostly to AEcl light emission and XRcl/XRfe light reflection. During the normal state, core layer  222  normally emits AEcl light, usually a majority component of A light. Total ATcl light consists of AEcl light, any ARcl light reflected by layer  222 , and any FE-structure-reflected ARfe light passing through it, usually mostly normally emitted AEcl light. Total ATab light consists of ADab light formed with AEcl light passing through NE structure  224 , any ARne light reflected by it, and any ARcl and ARfe light passing through it, likewise usually mostly AEcl light. Total ATcc light consists of AEcl light passing through NA layer  204 , any ARna light reflected by it, and any ARne, ARcl, and ARfe light passing through it, again usually mostly AEcl light. Including any ARis light reflected by IS component  182 , A light is formed with AEcl light and any ARis, ARna, ARne, ARcl, and ARfe light normally leaving component  182  and thus VC region  106 . 
     Core layer  222  in the mid-emission EN embodiment responds to the general CC control signal the same as in the mixed-reflection RN embodiment. Hence, the mid-emission EN embodiment operates the same in the changed state as the mid-reflection embodiment. 
     Assembly  202  in mid-emission EN or ET embodiment may be one or more of the following light-processing arrangements: a cathodoluminescent arrangement, an electrochromic fluorescent arrangement, an electrochromic luminescent arrangement, an electrochromic phosphorescent arrangement, an electroluminescent arrangement, an emissive microelectricalmechanicalsystem (display) arrangement (such as a time-multiplexed optical shutter or a backlit digital micro shutter structure), a field-emission arrangement, a light-emitting diode arrangement, a light-emitting electrochemical cell arrangement, an organic light-emitting diode arrangement, an organic light-emitting transistor arrangement, a photoluminescent arrangement, a plasma panel arrangement, a quantum-dot light-emitting diode arrangement, a surface-conduction-emission arrangement, and a vacuum fluorescent (display) arrangement. 
     Core layer  222  in each light-processing arrangement usually contains a multiplicity of light-emissive elements distributed laterally uniformly across layer  222 . “LE” hereafter means light-emissive. Each LE element lies between a small part of NE structure  224  and a generally oppositely situated small part of FE structure  226  for which these two parts of electrode structures  224  and  226  occupy approximately the same lateral area as that LE element. The LE elements continuously or selectively emit light during operation of OI structure  200  depending on factors such as their locations in layer  222 . The LE elements reflect light constituting part or all of the ARcl light during the normal state. Core segment  232  contains a submultiplicity of the LE elements. The LE elements in segment  232  reflect light constituting part or all of the XRcl light during the changed state. 
     During the normal state in the mid-emission ET embodiment of each light-processing arrangement with control voltage V nf  along core layer  222  at normal value V nfN , the LE elements either no light or emit light provided that little, preferably none, of the emitted light leaves layer  222  along NE structure  224 . When voltage V nf  along core segment  232  goes to value V nfC  to initiate the changed state, the LE elements in segment  232  emit XEcl light, again usually a majority component of X light, leaving segment  232 . When voltage V nf  along segment  232  returns to value V nfN , the LE elements in segment  232  return to emitting no light or to emitting light provided that little, preferably none, of the emitted light leaves segment  232  along NE segment  234 . 
     The opposite occurs in the mid-emission EN embodiment of each light-processing arrangement. With voltage V nf  along core layer  222  being value V nfN  during the normal state, the LE elements emit AEcl light, again usually a majority component of A light, leaving layer  222 . When voltage V nf  along core segment  232  goes to value V nfC  to initiate the changed state, the LE elements in segment  232  either emit no light or continue to emit light provided that little, preferably none, of the emitted light leaves segment  232  along NE segment  234 . When voltage V nf  along core segment  232  returns to value V nfN , the LE elements in segment  232  return to emitting AEcl light leaving it. 
     The LE elements are at fixed locations in core layer  222 , and thus in CC component  184 , in one version of the mid-emission ET or EN embodiment. In the mid-emission ET version, the LE elements emit no light during the normal state. In the mid-emission EN version, the LE elements in core segment  232  largely cease emitting light in response to the general CC control signal so as to emit no light during the changed state. 
     Each LE element has an element emissive area across which AEcl light is emitted during the normal state in the mid-emission EN embodiment and XEcl light is emitted during the changed state in the mid-emission ET embodiment if that LE element is in IDVC portion  138 . AEcl or XEcl light of each LE element can be emitted relatively uniformly across its emissive area. Alternatively, each LE element includes three or more LE subelements, each operable to emit light of a different one of three or more primary colors, e.g., red, green, and blue, combinable to produce many colors usually including white. Each LE subelement usually emits its primary color across a subelement emissive subarea of the emissive area of its LE element. The standard human eye/brain would interpret the combination of the primary colors of the light emitted by the LE subelements in each LE element of the mid-emission EN embodiment as color AEcl if the AEcl light traveled to the human eye unaccompanied by other light. The same applies to color XEcl and XEcl light for each LE element in portion  138  of the mid-emission ET embodiment. 
     The radiosities of the light of the primary colors emitted from each element emissive area can be programmably adjusted subsequent to manufacture of OI structure  200  for adjusting AEcl light, and thus A light, in the mid-emission EN embodiment and XEcl light, and thus X light, in the mid-emission ET embodiment. The programming is performed, as necessary, for each primary color, by providing the LE subelements operable for emitting light of that primary color with a programming voltage that causes them to emit light of their primary color at radiosity suitable for the desired AEcl light in the mid-emission EN embodiment and suitable for the desired XEcl light in the mid-emission ET embodiment. 
     Another version of the mid-emission ET or EN embodiment entails providing the LE elements in a supporting medium, usually a fluid such as a liquid, in core layer  222 . The supporting medium is a medium color M1Rc materially different from temporary emitted core color XEcl. Hence, the medium reflects M1Rc light and absorbs or/and transmits other light. The LE elements have electrical characteristics, typically electrical charging, which enable them to translate (move) in response to a changing electric field. Also, the LE elements are usually of an LE-element color L1Rc so as reflect L1Rc light and absorb or/and transmit, preferably absorb, other light. 
     In the mid-emission ET translating-element version, setting voltage V nf  at normal value V nfN  laterally along core layer  222  results in the LE elements being normally distributed in the medium such that, even if they emit light, largely none of the emitted light leaves layer  222  along NE structure  224 . Specifically, the LE elements are normally dispersed throughout the medium or situated adjacent to FE structure  226  so as to be averagely remote from NE structure  224 . The medium absorbs any light emitted by the LE elements and traveling toward structure  224 . Since the medium reflects M1Rc light and since the LE elements reflect L1Rc light, ARcl light normally leaving layer  222  consists of M1Rc light and any L1Rc light. Total ATcl light consists of M1Rc light and any L1Rc and XRfe light. Any LiRc light normally leaving layer  222  along structure  224  is of low radiosity compared to M1Rc light normally leaving layer  222  along structure  224 . 
     The V nfC  polarity and the characteristics, e.g., charging, of the LE elements are chosen such that the LE elements in core segment  232  translate so as to be adjacent to NE segment  234  when voltage V nf  along segment  232  goes to changed value V nfC . The LE elements in segment  232  then emit XEcl light leaving it. With XRcl light leaving segment  232  consisting of M1Rc and L1Rc light, total XTcl light consists of XEcl, M1Rc, and L1Rc light and any ARfe light so as to differ materially from the ATcl light normally leaving core layer  222 . The same result is achieved by reversing both the V nfC  polarity and the characteristics of the LE elements. 
     The mid-emission EN translating-element version operates in the opposite way. Setting voltage V nf  at value V nfN  laterally along core layer  222  results in the LE elements normally being adjacent to NE structure  224 . The LE elements normally emit AEcl light leaving layer  222 . Since the medium reflects M1Rc light and since the LE elements reflect L1Rc light, ARcl light normally leaving layer  222  consists of M1Rc and L1Rc light. Total ATcl light consists of AEcl, M1Rc, and L1Rc light and any ARfe light. 
     Changing voltage V nf  in core segment  232  to value V nfC  causes the LE elements in segment  232  to translate so as to be averagely remote from NE segment  234 . In particular, the LE elements in segment  232  become dispersed throughout it or situated adjacent to FE segment  236 . The segment of the medium in core segment  232  absorbs any light emitted by the LE elements in segment  232  and traveling toward NE segment  234 . With XRcl light leaving segment  232  consisting largely of M1Rc light and any L1Rc light, total XTcl light consists largely of M1Rc light and any L1Rc and ARfe light and differs materially from the ATcl light normally leaving core layer  222 . Any LiRc light temporarily leaving segment  232  along NE segment  234  is of low radiosity compared to M1Rc light temporarily leaving segment  232  along NE segment  234 . The same result is again achieved by reversing both the V nfC  polarity and the characteristics of the LE elements. 
     Various mechanisms can cause the LE elements in the translating-element version of the mid-emission ET or EN embodiment to emit XEcl or AEcl light. The LE elements can emit light an electrochromic fluorescently, electrochromic luminescently, electrochromic phosphorescently, or electroluminescently in response to an alternating-current voltage signal imposed on voltage V nf . The LE elements can emit light photoluminescently in response to electromagnetic radiation provided from a source outside assembly  202 . “EM” hereafter means electromagnetic. The EM radiation is typically IR radiation but can be light or UV radiation, usually UV radiation just beyond the visible spectrum. The radiation source is typically in FA layer  206  but can be in NA layer  204 . The EM radiation can sometimes simply be ambient light. In addition, the LE elements can sometimes emit light naturally, i.e., without external stimulus. 
     The LE elements in the translating-element version of the mid-emission ET or EN embodiment can emit light continuously during operation of OI structure  200 . This can occur in response to EM radiation provided from a source of EM radiation. If so and if the EM radiation source is capable of being switched between radiating (on) and non-radiating (off) states, the radiation source is usually placed in the non-radiating state when structure  200  is out of operation so as to save power. Alternatively, the LE elements in core segment  232  of the mid-emission ET version can emit XEcl light in response to the general CC control signal but be non-emissive of light at other times. In a complementary manner, the LE elements in segment  232  of the mid-emission EN version can normally emit AEcl light and become non-emissive of light in response to the control signal. 
     The mid-emission EN-ET embodiment utilizes normal AEab light emission-ARab light reflection and temporary XEab light emission-XRab light reflection or, more specifically, normal AEcl light emission-ARne/ARcl/ARfe light reflection and temporary XEcl light emission-ARne/XRcl/XRfe light reflection respectively due mostly to AEcl light emission and XEcl light emission. The mid-emission EN-ET embodiment operates the same during the normal state as the mid-emission EN embodiment. Core segment  232  in the mid-emission EN-ET embodiment responds to the general CC control signal the same as in the mid-emission ET embodiment. Hence, the mid-emission EN-ET embodiment operates the same during the changed state as the mid-emission ET embodiment. 
     Assembly  202  in the mid-emission EN-ET embodiment can generally be any one or more of the above light-processing arrangements usable to implement the mid-emission EN and ET embodiments subject to modification of each light-processing arrangement to be capable of emitting both AEcl light and XEcl light. In one modification, core layer  222  contains a multiplicity of first LE elements distributed laterally uniformly across layer  222  and a multiplicity of second LE elements distributed laterally uniformly across layer  222  and thus approximately uniformly among the first LE elements. Each LE element lies between a small part of NE structure  224  and a generally oppositely situated small part of FE structure  226  for which these two parts of electrode structures  224  and  226  occupy approximately the same lateral area as that LE element. Core segment  232  contains a submultiplicity of the first LE elements and a submultiplicity of the second LE elements. The mechanisms causing the first and second LE elements to emit light are the same as those described above for causing the LE elements in the above-described version of the mid-emission ET or EN embodiment to emit light. 
     The first and second LE elements, i.e., all the properly functioning ones, have the following light-emitting capabilities. The first LE elements emit light of wavelength for a first LE emitted color P1Ec during the normal state in which voltage V nf  between electrode structures  226  and  224  is at value V nfN  such that P1Ec light leaves core layer  222  and exits VC region  106 . During the changed state with voltage V nf  between the two parts of structures  226  and  224  for each LE element in core segment  232  at value V nfC , the first LE elements outside segment  232  continue to emit P1Ec light leaving layer  222  and exiting region  106 . The first LE elements in segment  232  may or may not emit P1Ec light leaving segment  232  and exiting IDVC portion  138  during the changed state depending on which of the switching modes, described below, is used. The circumstance of a first LE element in segment  232  not providing light leaving portion  138  during the changed state can be achieved by having that element temporarily be non-emissive or by having it emit light that temporarily does not leave portion  138 , e.g., due to absorption in segment  232 . 
     The second LE elements in core segment  232  emit light of wavelength for a second LE emitted color Q1Ec during the changed state such that Q1Ec light leaves segment  232  and exits IDVC portion  138 . The second LE elements outside segment  232  may or may not emit Q1Ec light which leaves core layer  222  and exits VC region  106  during the changed state depending on which of the switching modes is used. The same applies to the second LE elements during the normal state. The circumstance of a second LE element not providing light leaving region  106  during the normal or changed state can be achieved by having that element normally or temporarily be non-emissive or by having it emit light that normally or temporarily does not leave region  106 , e.g., due to absorption in layer  222 . 
     Additionally, the first LE elements usually reflect light striking them and of wavelength for a first LE reflected color P1Rc while absorbing or/and transmitting, preferably absorbing, other incident light. P1Rc light may or may not leave core layer  222  and exit VC region  106  during the normal and changed states. Similarly, the second LE elements usually reflect light striking them and of wavelength for a second LE reflected color Q1Rc while absorbing or/and transmitting, preferably absorbing, other incident light. Q1Rc light may or may not leave layer  222  and exit region  106  during the normal and changed states. 
     Subject to the preceding emission/reflection specifications, the first and second LE elements operate in one of the following three switching modes. In a first LE switching mode, the first and second LE elements respectively normally emit P1Ec and Q1Ec light which forms AEcl light, usually a majority component of A light, leaving core layer  222  along NE structure  224  and then leaving VC region  106  via SF zone  112 . Total ATcl light consists of P1Ec and Q1Ec light and any ARcl and ARfe light, usually mostly P1Ec and Q1Ec light, where the ARcl light includes any P1Rc and Q1Rc light. The first LE elements in core segment  232  respond to the general CC control signal by temporarily largely ceasing to emit light leaving IDVC portion  138  via print area  118 . The second LE elements in segment  232  continue to emit Q1Ec light which forms XEcl light, usually a majority component of X light, leaving segment  232  along NE segment  234  and then leaving portion  138  via area  118 . Total XTcl light consists largely of Q1Ec light and any XRcl and ARfe light, usually mostly Q1Ec light, where the XRcl light includes any P1Rc and Q1Rc light. 
     In a second LE switching mode, the first LE elements normally emit P1Ec light which forms AEcl light, usually a majority component of A light, leaving core layer  222  along NE structure  234  and then leaving VC region  106  via SF zone  112 . The second LE elements normally emit largely no light leaving region  106  along zone  112 . Total ATcl light consists largely of P1Ec light and any ARcl and ARfe light, usually mostly P1Ec light, where the ARcl light again includes any P1Rc and Q1Rc light. Upon occurrence of the general CC control signal, the first LE elements in core segment  232  continue to emit P1Ec light leaving it along NE segment  234  and then leaving IDVC portion  138  via print area  118 . The second LE elements in core segment  232  respond to the general CC control signal by temporarily emitting Q1Ec light leaving segment  232  via NE segment  234  and then leaving portion  138  via area  118 . P1Ec and Q1Ec light form XEcl light, usually a majority component of X light. Total XTcl light consists of P1Ec and Q1Ec light and any XRcl and ARfe light, usually mostly P1Ec and Q1Ec light, where the XRcl light again includes any P1Rc and Q1Rc light. 
     In a third LE switching mode, the first and second LE elements operate the same during the normal state as in the second LE switching mode. The first LE elements in core segment  232  respond to the general CC control signal by temporarily largely ceasing to emit light leaving IDVC portion  138  along print area  118 . The second LE elements in segment  232  respond to the control signal by temporarily emitting Q1Ec light which forms XEcl light, usually a majority component of X light, temporarily leaving segment  232  along NE segment  234  and then leaving portion  138  along area  118 . As in the first LE switching mode, total XTcl light consists largely of Q1Ec light and any XRcl and ARfe light, usually mostly Q1Ec light, where the XRcl light includes any P1Rc and Q1Rc light. 
     The first and second LE elements are at fixed locations in core layer  222  and thus in CC component  184  in a version of the mid-emission EN-ET embodiment implementing each LE switching mode. During the normal state in the version implementing the third LE switching mode, the first LE elements emit P1Ec light while the second LE elements emit no light. During the changed state, the second LE elements in core segment  232  temporarily emit Q1Ec light in response to the general CC control signal while the first LE elements in segment  232  become non-emissive in response to the control signal. 
     When the first and second LE elements are fixedly located in core layer  222 , those LE elements also usually have the physical characteristics of the fixed-location LE elements in the mid-emission ET or EN embodiment. Accordingly, each first or second LE element can include three or more LE subelements, each operable to emit light of a different one of three or more primary colors, e.g., again red, green, and blue, combinable to produce many colors usually including white. The standard human eye/brain would interpret the combination of the primary colors of the light emitted by the first or second LE subelements in each LE element as color P1Ec or Q1Ec if the P1Ec or Q1Ec light traveled to the human eye unaccompanied by other light. 
     The radiosities of the light of the primary colors emitted from each emissive area can be programmably adjusted subsequent to manufacture of OI structure  200  for enabling AEcl and XEcl light, and thus A and X light, to be adjusted. The programming is performed, as necessary, for each primary color, by providing the LE subelements operable for emitting light of that primary color with a selected programming voltage that causes those LE subelements to emit their primary color at radiosities suitable for the desired AEcl and XEcl light. 
     Another version of the mid-emission EN-ET embodiment implementing the third LE switching mode entails providing the two sets of LE elements in a supporting medium, usually a fluid such as a liquid, in core layer  222 . The supporting medium is again generally of medium color M1Rc. The medium is preferably transparent so that the M1Rc radiosity is close to zero. The LE elements have electrical characteristics, typically electrical charging, which enable the second LE elements to translate oppositely to the first LE elements in the presence of an electric field. Setting voltage V nf  at normal value V nfN  laterally along layer  222  causes the first LE elements to be adjacent to NE structure  224  while the second LE elements are averagely remote from structure  224 . In particular, the second LE elements are normally dispersed throughout the medium or situated adjacent to FE structure  226 . The first LE elements emit P1Ec light leaving layer  222  along NE structure  224  and then VC region  106  via SF zone  112 . The medium absorbs light emitted by the second LE elements and traveling toward structure  224 . Since the medium reflects M1Rc light and since the first and second LE elements respectively reflect P1Rc and Q1Rc light, total ATcl light consists largely of P1Ec and P1Rc light and any Q1Rc, M1Rc, and ARfe light. Any Q1Rc light normally leaving layer  222  along structure  224  is of low radiosity compared to P1Rc light normally leaving layer  222  along structure  224 . 
     The V nfC  polarity and the characteristics, e.g., charging, of the LE elements are chosen such that changing voltage V nf  along core segment  232  to value V nfC  causes the second LE elements in segment  232  to translate so as to be adjacent to NE segment  234  while the first LE elements in core segment  232  oppositely translate so as to be averagely remote from NE segment  234 . In particular, the first LE elements in core segment  232  become temporarily dispersed throughout the segment of the medium in segment  232  or situated adjacent to FE segment  236 . The second LE elements in core segment  232  emit Q1Ec light leaving segment  232  along NE segment  234  and then IDVC portion  138  via print area  118 . The medium absorbs light emitted by the first LE elements in core segment  232  and traveling toward NE segment  234 . With the segment of the medium in core segment  232  reflecting M1Rc light and with the first and second LE elements respectively reflecting P1Rc and Q1Rc light, total XTcl light consists largely of Q1Ec and Q1Rc light and any P1Rc, M1Rc, and ARfe light and differs materially from the ATcl light normally leaving core layer  222 . During the changed state, any P1Rc light leaving segment  232  along NE segment  234  is of low radiosity compared to Q1Rc light leaving segment  232  along NE segment  234 . 
     The first and second LE elements may emit light continuously during operation of OI structure  200  in the preceding version of the mid-emission EN-ET embodiment. This can occur in response to EM radiation provided from an EM radiation source. If so and if the radiation source can be switched between radiating and non-radiating states, the radiation source is usually placed in the non-radiating state when structure  200  is out of operation so as to save power. Alternatively, the second LE elements in core segment  232  can emit XEcl light in response to the general CC control signal but be non-emissive at other times while the first LE elements emit AEcl light continuously during operation of structure  200  or normally emit AEcl light but become non-emissive in response to the control signal. 
     Moving to the three deep-emission embodiments of CC component  184 , FA layer  206  is utilized in each deep-emission embodiment for emitting light in making color change. The difference between the single deep-emission embodiments is that light emitted by layer  206  passes through core layer  222  only during the changed state in the deep-emission ET embodiment but only in the normal state in the deep-emission EN embodiment. Light emitted by FA layer  206  passes through core layer  222  during both states in the deep-emission EN-ET embodiment. 
     The deep-emission ET embodiment employs normal ARab light reflection and temporary XEfa light emission-XRab/XRfa light reflection or, more specifically, normal ARne/ARcl/ARfe light reflection and temporary XEfa light emission-ARne/XRcl/XRfe/XRfa light reflection respectively due mostly to ARcl/ARfe light reflection and XEfa light emission. The deep-emission ET embodiment is similar to the mixed-reflection RT embodiment except that FA layer  206  in the deep-emission ET embodiment emits light and lacks the light reflector of the mixed-reflection RT embodiment. During the normal state, the deep-emission ET embodiment operates the same as the mid-emission ET embodiment and thus the same as the mid-reflection embodiment. 
     Core segment  232  in the deep-emission ET embodiment responds to the general CC control signal applied between at least oppositely situated parts of electrode segments  234  and  236  during the changed state by allowing a substantial part of XEfa light, usually a majority component of X light, emitted by FA segment  216  and passing through FE segment  236  to temporarily pass through core segment  232 . Total XTfa light consists of XEfa light and any XRfa light reflected by FA segment  216 , usually mostly emitted XEfa light. 
     A substantial part of any XRfa light passes through FE segment  236  and, as allowed by core segment  232 , through it. Total XTcl light consists of XEfa light passing through segment  232 , any XRfa light passing through it, any XRcl light reflected by it, and any FE-segment-reflected XRfe light passing through it, usually mostly XEfa light. Total XTab light consists of XEfa light passing through NE segment  234 , any XRfa light passing through it, and any XRab light formed with any ARne light reflected by it and any XRcl and XRfe light passing through it, likewise usually mostly XEfa light. Total XTcc light consists of XEfa light passing through NA segment  214 , any ARna light reflected by it, and any ARne, XRcl, XRfe, and XRfa light passing through it, again usually mostly XEfa light. Including any ARis light reflected by IS segment  192 , X light is formed with XEfa light and any ARis, ARna, ARne, XRcl, XRfe, and XRfa light temporarily leaving segment  192  and thus IDVC portion  138 . XEfa light is preferably a 75% majority component, more preferably a 90% majority component, of each of XTfa, XTcl, XTab, XTcc, and X light. 
     The deep-emission EN embodiment employs normal AEfa light emission-ARab/ARfa light reflection and temporary XRab light reflection or, more specifically, normal AEfa light emission-ARne/ARcl/ARfe/ARfa light reflection and temporary ARne/XRcl/XRfe light reflection respectively due mostly to AEfa light emission and XRcl/XRfe light reflection. The deep-emission EN embodiment is similar to the mixed-reflection RN embodiment except that FA layer  206  in the deep-emission EN embodiment emits light and lacks the light reflector of the single mixed-reflection RN embodiment. During the normal state, core layer  222  in the deep-emission EN embodiment allows AEfa light, usually a majority component of A light, emitted by FA layer  206  and passing through FE structure  226  to pass through core layer  222 . Total ATfa light consists of AEfa light and any ARfa light reflected by FA layer  206 , usually mostly emitted AEfa light. 
     A substantial part of any ARfa light passes through FE structure  226  and, as allowed by core layer  222 , through it. Total ATcl light consists of AEfa light passing through layer  222 , any ARfa light passing through it, any ARcl light reflected by it, and any FE-structure-reflected ARfe light passing through it, usually mostly emitted AEfa light. Total ATab light consists of AEfa light passing through NE structure  224 , any ARfa light passing through it, and any ARab light formed with any ARne light reflected by structure  224  and any ARcl and ARfe light passing through it, likewise usually mostly emitted AEfa light. Total ATcc light consists of AEfa light passing through NA layer  204 , any ARna light reflected by it, and any ARne, ARcl, ARfe, and ARfa light passing through it, again usually mostly AEfa light. Including any ARis light reflected by IS component  182 , A light is formed with AEfa light and any ARis, ARna, ARne, ARcl, ARfe, and ARfa light temporarily leaving component  182  and thus VC region  106 . AEfa light is preferably a 75% majority component, more preferably a 90% majority component, of each of ATfa, ATcl, ATab, ATcc, and A light. 
     Core segment  232  in the deep-emission EN embodiment responds to the general CC control signal the same as in the mid-emission EN embodiment. Consequently, the deep-emission EN embodiment operates the same during the changed state as the mid-reflection embodiment. 
     In one implementation of the deep-emission ET or EN embodiment, core layer  222  contains dimensionally anisotropic core particles distributed laterally across the layer&#39;s extent and switchable between light-transmissive and light-blocking states. The core particles have the characteristics described above for the implementation of the mixed-reflection RT or RN embodiment utilizing dimensionally anisotropic core particles. NA layer  204  may or may not be present in this deep-emission ET or EN implementation. FA layer  206  in the deep-emission ET or EN implementation contains a light emitter extending along, and generally parallel to, FE structure  226 . The deep-emission ET or EN implementation is configured the same as the implementation of the mixed-reflection RT or RN embodiment utilizing anisotropic core particles except that the light emitter replaces the light reflector. The deep-emission ET or EN implementation operates the same as the mixed-reflection RT or RN implementation utilizing anisotropic core particles except as described below. 
     The deep-emission ET implementation operates the same as the mixed-reflection RT implementation utilizing anisotropic core particles except that, during the changed state, the combination of XEfa light emitted by the segment of the light emitter in FA segment  216  and any XRfa light reflected by segment  216  replaces XRfa light reflected by the segment of the light reflector in segment  216 . The light emitter may continuously emit XEfa light during operation of the deep-emission ET implementation. Alternatively, the light emitter may respond to the general CC control signal by emitting XEfa light only during the changed state in order to reduce power consumption. 
     The deep-emission EN implementation operates the same as the mixed-reflection RN implementation utilizing anisotropic core particles except that, during the normal state, the combination of AEfa light emitted by the light emitter and any ARfa light reflected by FA layer  206  replaces ARfa light reflected by the light reflector. The light emitter usually continuously emits AEfa light during operation of the deep-emission EN implementation. 
     Core layer  222  consists of LC material formed with elongated LC molecules constituting the core particles in one version of the deep-emission ET or EN implementation for which CC component  184  consists of a reflective LC arrangement, typically polarizer-free. In another version of the deep-emission ET or EN implementation, layer  222  is formed with a fluid, typically a liquid, in which dipolar particles constituting the core particles are colloidally suspended. These two versions of the deep-emission ET or EN implementation are respectively configured and operable as described above for the two versions of the mixed-reflection RT or RN implementation utilizing anisotropic core particles formed respectively with elongated LC molecules and with dipolar particles subject to (a) the light emitter replacing the light reflector, (b) the changed-state combination of XEfa light emitted by the segment of the light emitter in FA segment  216  and any XRfa light reflected by segment  216  replacing XRfa light reflected by the segment of the light reflector in segment  216 , and (c) the normal-state combination of AEfa light emitted by the light emitter and any ARfa light reflected by FA layer  206  replacing ARfa light reflected by the light reflector. 
     The deep-emission EN-ET embodiment employs normal AEfa light emission-ARab/ARfa light reflection and temporary XEfa light emission-XRab/XRfa light reflection or, more specifically, normal AEfa light emission-ARne/ARcl/ARfe/ARfa light reflection and temporary XEfa light emission-ARne/XRcl/XRfe/XRfa light reflection respectively due mostly to AEfa light emission and XEfa light emission. The deep-emission EN-ET embodiment is similar to the deep-reflection embodiment except that FA layer  206  in the deep-emission EN-ET embodiment emits light and lacks the strong light-reflection capability of the deep-reflection embodiment. Core layer  222  and auxiliary layers  204  and  206  are usually employed in the deep-emission EN-ET embodiment for imposing certain traits, usually WI traits such as PZ traits, on light emitted by FA layer  206  and passing through FE structure  226 , core layer  222 , NE structure  224 , NA layer  204 , and IS component  182 . In particular, the deep-emission EN-ET embodiment operates the same as the deep-reflection embodiment when WI traits are employed except as described below. 
     During the normal state, FA layer  206  emits AEfa light, usually a majority component of A light. Layer  206  also typically reflects ARfa light. Total ATfa light consists of AEfa light and any ARfa light, usually mostly emitted AEfa light. Layer  206  typically imposes the FA trait on the AEfa light and on at least part of the ARfa light. 
     The remaining light processing during the normal state in the deep-emission EN-ET embodiment is the same as in the deep-reflection embodiment except that the combination of AEfa light and any ARfa light replaces ARfa light. Total ATfe light consists of AEfa light passing through FE structure  226 , any ARfa light passing through it, and any ARfe light reflected by it, usually mostly AEfa light. ATfe light passing through core layer  222  has the primary outgoing trait upon reaching NA layer  204 . Total ATcl light consists of AEfa light passing through core layer  222 , any ARcl light reflected by it, and any ARfe and ARfa light passing through it, usually mostly AEfa light having the primary outgoing trait. Total ATab light consists of AEfa light passing through NE structure  224 , any ARfa light passing through it, and any ARab light formed with any ARne light reflected by structure  224  and any ARcl and ARfe light passing through it, likewise usually mostly AEfa light. 
     ATab light passing through NA layer  204  typically has the NA outgoing trait upon reaching IS component  182 . Total ATcc light consists of AEfa light passing through layer  204 , any ARna light reflected by it, and any ARne, ARcl, ARfe, and ARfa light passing through it, again usually mostly AEfa light. Including any ARis light normally reflected by component  182 , A light is formed with AEfa light and any ARis, ARna, ARne, ARcl, ARfe, and ARfa light normally leaving component  182  and thus VC region  106 . AEfa light is preferably a 75% majority component, more preferably a 90% majority component, of each of ATfa, ATcl, ATab, ATcc, and A light. 
     During the changed state, core segment  232  responds to the general CC control signal applied between at least oppositely situated parts of electrode segments  234  and  236  by allowing XEfa light, usually a majority component of X light, emitted by FA segment  216  and passing through FE segment  236  to temporarily pass through core segment  232 . FA segment  216  typically reflects XRfa light, usually largely ARfa light. Total XTfa light consists of XEfa light and any XRfa light, usually mostly emitted XEfa light. Segment  216  typically imposes the FA trait on the XEfa light and on at least part of the XRfa light. 
     The remaining light processing during the changed state in the deep-emission EN-ET embodiment is the same as in the deep-reflection embodiment except that the combination of XEfa light and any XRfa light replaces XRfa light. Total XTfe light consists of XEfa light passing through FE segment  236 , any XRfa light passing through it, and any ARfe light reflected by it, usually mostly XEfa light. XTfe light passing through core segment  232  has the changed outgoing trait upon reaching NA segment  214 . Total XTcl light consists of XEfa light passing through core segment  232 , any XRcl light reflected by it, and any XRfe and XRfa light passing through it, usually mostly XEfa light having the changed outgoing trait. Total XTab light consists of XEfa light passing through NE segment  234 , any XRfa light passing through it, and any XRab light formed with any ARne light reflected by segment  234  and any XRcl and XRfe light passing through it, likewise usually mostly XEfa light. 
     XTab light passing through NA segment  214  typically has the NA outgoing trait upon reaching IS segment  192 . Total XTcc light consists of XEfa light passing through NA segment  214 , any ARna light reflected by it, and any ARne, XRcl, XRfe, and XRfa light passing through it, again usually mostly XEfa light. Including any ARis light reflected by IS segment  192 , X light is formed with XEfa light and any ARis, ARna, ARne, XRcl, XRfe, and XRfa light temporarily leaving segment  192  and thus IDVC portion  138 . XEfa light is preferably a 75% majority component, more preferably a 90% majority component, of each of XTfa, XTcl, XTab, XTcc, and X light. 
     While the primary outgoing and changed outgoing traits are independent of wavelength, the material difference between them is chosen to result in temporary total core color XTcl differing materially from normal total core color ATcl in the deep-emission EN-ET embodiment. This often results from the radiosity of the XEfa component in the XTcl light during the changed state differing materially from, usually being materially less than, the radiosity of the AEfa component in the ATcl light during the normal state due to the material difference between the primary outgoing and changed outgoing traits so that the XTcl and ATcl light differ materially in radiosity. Color X differs materially from color A. 
     One embodiment of the deep-emission EN-ET embodiment of CC component  184  is a backlit LC structure in which core layer  222  consists largely of LC material such as nematic liquid crystal formed with elongated LC particles. FA layer  206  contains a light emitter such as a lamp extending parallel to, and along all of, assembly  202  so as to emit light, usually of uniform radiosity, leaving layer  206  along all of assembly  202 . 
     The backlit LC structure is configured the same as the reflective LC structure of the deep-reflection embodiment except that the light emitter replaces the light reflector. NA layer  204  again contains a near plane polarizer extending along, and generally parallel to, NE structure  224 . FA layer  206  contains a far plane polarizer extending along, and generally parallel to, FE structure  226  so as to lie between structure  226  and the light emitter. The PZ direction of the far polarizer again typically extends perpendicular to, or parallel to, the PZ direction of the near polarizer but can extend at a non-zero angle materially different from 90° to the PZ direction of the near polarizer. The backlit LC structure with perpendicular polarizers operates the same as the reflective LC structure with perpendicular polarizers except as described below. 
     The light emitter emits, usually continuously during operation of OI structure  200 , AEfa light that impinges on the far polarizer. With the emitted light consisting of p and s directional components defined relative to the near polarizer so that the PZ direction of the far polarizer extends in the s direction, the far polarizer transmits a high percentage of the s component and blocks, preferably absorbs, the p component. Emitted AEfa light and any reflected ARfa light passing through the far polarizer so as to strike FE structure  226  and core layer  222  are plane polarized in the s direction. This action occurs during both the normal and changed states with structure  226  and layer  222 . 
     During the normal state, the combination of AEfa light and any ARfa light undergoes the same further processing that ARfa light undergoes in the deep-reflection embodiment. Specifically, the LC material causes incident s polarized AEfa light and any ARfa light to undergo a rotation in PZ direction largely equal to the primary LC amount. The near polarizer blocks, preferably absorbs, any incident light plane polarized in largely any direction other than the p direction so that light passing through the near polarizer includes AEfa light and any ARfa light plane polarized in the p direction. 
     During the changed state, core layer  222  here responds to the general CC control signal the same as in the deep-reflection embodiment. The combination of XEfa light and any XRfa light undergoes the same further processing that XRfa light undergoes in the deep-reflection embodiment. More particularly, to the extent that the PZ direction of any incoming p polarized XRna light leaving the near polarizer segment in NA segment  214  undergoes rotation in core segment  232 , the LC segment in segment  232  causes incident s polarized XEfa light and any XRfa light to undergo the same rotation in PZ direction. The near polarizer segment in NA segment  214  blocks, preferably absorbs, any incident light plane polarized in any direction other than the p direction so that light passing through the near polarizer segment in segment  214  includes XEfa light and any XRfa light plane polarized in the p direction. The radiosity of the p plane polarized XEfa light passing through the near polarizer segment in segment  214  during the changed state differs materially from, is usually materially less than, the radiosity of the p plane polarized AEfa light passing through the near polarizer during the normal state because the radiosity of the s plane polarized XEfa light passing through the far polarizer segment in FA segment  216  during the changed state differs materially from the radiosity of the s plane polarized AEfa light passing through the far polarizer during the normal state due to the effective PZ direction rotation, if any, provided by core segment  232  during the changed state differing materially from, usually being materially less than, the effective PZ direction rotation provided by core layer  222  during the normal state. 
     Similar to what occurs with colors ARfa and XRfa in the deep-reflection embodiment, colors AEfa and XEfa normally have the same wavelength characteristics. However, the material difference in radiosity between the resultant p plane polarized XEfa light leaving NA segment  214  during the changed state and the resultant p plane polarized AEfa light leaving NA layer  204  during the normal state by itself, or in combination with other reflected light leaving print area  118  during the changed state and SF zone  112  during the normal state enables color X to differ materially from color A. With color XEfa being at materially lower radiosity than color AEfa, color X is again materially lighter than color A even though even though the wavelength characteristics of XEfa and AEfa light are the same. 
     The mid-emission ET, mid-emission EN-ET, deep-emission ET, and deep-emission EN-ET embodiments are advantageous because use of light emission to produce changed color X enables print area  118  to be quite bright. Visibility of the color change is enhanced, especially in dark ambient environments where certain colors are difficult to distinguish. 
     Object-Impact Structure Having Surface Structure for Protection, Pressure Spreading, and/or Velocity Restitution Matching 
       FIGS. 13 a -13 e    (collectively “ FIG. 13 ”) illustrate an extension  240  of OI structure  130 . OI structure  240  is configured the same as structure  130 , e.g., ISCC structure  132  can be embodied as CR or CE material, except that VC region  106  here includes a principal SF structure  242  extending from SF zone  112  to meet ISCC structure  132  along a flat principal structure-structure interface  244  extending parallel to zone  112 . See  FIG. 13 a   . SF structure  242  performs various functions such as protecting ISCC structure  132  from damage and/or spreading pressure to improve the matching between print area  118  and OC area  116  during impact on zone  112 . For either of these functions, structure  242  typically consists largely of insulating material along all of zone  112 . Structure  242  may provide velocity restitution matching between SF zones  112  and  114  as discussed below for  FIGS. 102 a  and 102 b   . Structure  242  is usually transparent but may nonetheless strongly influence principal color A or/and changed color X. 
     Light travels through SF structure  242 . ISCC structure  132  here operates the same during the normal state as in OI structure  130  except that light leaving ISCC structure  132  via SF zone  112  in OI structure  130  leaves ISCC structure  132  via interface  244  here. The total light, termed ATic light, normally leaving structure  132  consists of ARic light reflected by it, any AEic light emitted by it, and any substructure-reflected ARsb light passing through it. 
     Substantial parts of the ARic light, any AEic light, and any ARsb light pass through SF structure  242 . Additionally, structure  242  may normally reflect light, termed ARss light, which leaves it via SF zone  112  after striking zone  112 . ARic light and any AEic, ARss, and ARsb light normally leaving structure  242 , and thus VC region  106 , form A light. Each of ADic light and either ARic or AEic light is again usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of A light. ARss light may, however, be a majority component of A light if structure  242  strongly influences principal color A. 
     SF structure  242  usually absorbs some light. Hence, ATic light reaching SF zone  112  so as to leave VC region  106  can be of significantly lower radiosity than total ATic light directly leaving ISCC structure  132  along interface  244 . To the extent that light absorption by SF structure  242  is significantly wavelength dependent, light incident on zone  112  and of wavelength significantly absorbed by structure  242  is considerably attenuated before reaching interface  244 . ARic light reflected by ISCC structure  132  is of comparatively low spectral radiosity at the spectral radiosity constituency of incident light absorbed by SF structure  242  because that light does not reach interface  244  so as to be reflected by ISCC structure  132  and included in the ARic light leaving structure  132 . ARic light reaching zone  112  is usually of the same spectral radiosity constituency as the ARic light directly leaving structure  132 . If ARic light leaving structure  132  is the same in both OI structures  130  and  240 , the ARic light leaving structure  240  can be of considerably different spectral radiosity constituency than ARic light leaving structure  130  because it lacks SF structure  242  and does not undergo such wavelength-dependent absorption. Insofar as undesirable, this situation is alleviated by choosing the light-absorption characteristics of structure  242  to significantly avoid absorbing light at the spectral radiosity constituency of ARic light directly leaving ISCC structure  132 . 
     The circumstances differ somewhat with any AEic light emitted by ISCC structure  132 . Any component of AEic light leaving structure  132  at wavelength significantly absorbed by SF structure  242  is considerably attenuated before reaching SF zone  112  due to absorption in structure  242 . AEic light reaching zone  112  so as to leave VC region  106  can be of considerably different spectral radiosity constituency than the AEic light directly leaving ISCC structure  132 . If AEic light leaving structure  132  is the same in OI structures  130  and  240 , AEic light leaving structure  240  can also be of considerably different spectral radiosity constituency than AEic light leaving structure  130  because it lacks structure  242  and does not undergo such wavelength-dependent absorption. To the extent undesirable, this situation is alleviated by choosing the light-absorption characteristics of structure  242  to significantly avoid absorbing light at the spectral radiosity constituency of AEic light directly leaving ISCC structure  132 . 
     Referring to  FIGS. 13 b  and 13 c   , item  252  is the ID segment of SF structure  242  present in IDVC portion  138 . Print area  118 , the upper surface of portion  138 , is also the upper surface of surface-structure segment  252  here. “SS” hereafter means surface-structure. Item  254  is the ID segment of interface  244  present in portion  138 . In  FIGS. 13 b  and 13 c    and in analogous later side cross-sectional drawings, ID IF segment  254  is shown with extra thick line to clearly identify its exemplary location along interface  244 . 
     The impact of object  104  on OC area  116  creates excess SF pressure along area  116 . The excess SF pressure is transmitted through SF structure  242  to interface  244  for producing excess internal pressure along an ID distributed-pressure area  256  of interface  244 . “DP” hereafter means distributed-pressure. ID internal DP IF area  256  is situated opposite, and laterally outwardly conforms to, OC area  116 . IF area  256  is usually larger than, and usually extends laterally beyond, OC area  116  as shown in the example of  FIGS. 13 b  and 13 c    and as arises when structure  242  provides pressure spreading. While IF area  256  can be smaller than OC area  116 , this results in print area  118  being even smaller than OC area  116 . 
     ISCC segment  142  responds (a) in some general OI embodiments to the excess internal pressure along DP IF area  256 , specifically IF segment  254 , by causing IDVC portion  138  to temporarily appear as color X if the excess internal pressure along segment  254  meets the above-described principal basic excess internal pressure criteria here requiring that the excess internal pressure at a point along interface  244  equal or exceed a local TH value in order for the corresponding point along SF zone  112  to temporarily appear as color X or (b) in other general OI embodiments to the general CC control signal generated in response to the excess internal pressure along segment  254  meeting the excess internal pressure criteria sometimes dependent on other impact criteria also being met in those other embodiments by causing portion  138  to temporarily appear as color X. The changed state begins as portion  138  goes to a condition in which XRic light reflected by ISCC segment  142  and any XEic light emitted by it temporarily leave it along IF segment  254 . The total light, termed XTic light, temporarily leaving ISCC segment  142  consists of XRic light, any XEic light, and any substructure-reflected XRsb light passing through it. 
     Substantial parts of the XRic light, any XEic light, and any XRsb light pass through ID SS segment  252 . If SF structure  242  reflects ARss light during the normal state, SS segment  252  reflects ARss light during the changed state. XRic light and any XEic, ARss, and XRsb light leaving segment  252 , and thus IDVC portion  138 , form X light. XDic light differs materially from A and ADic light. Each of XDic light and either XRic or XEic light is again usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of X light. If structure  242  strongly influences A light especially if ARss light is a majority component of A light, ARss light usually has a significant effect on X light. The contributions of ARss light to A and X light are chosen so that color X materially differs from color A. 
     Analogous to what occurs with ATic light, XTic light reaching print area  118  so as to leave IDVC portion  138  can be of significantly lower radiosity than total XTic light directly leaving ISCC segment  142  along IF segment  254  due to light absorption by SS segment  252 . To the extent that light absorption by segment  252  is significantly wavelength dependent, light incident on area  118  and of wavelength significantly absorbed by segment  252  is considerably attenuated before reaching IF segment  254 . XRic light reflected by ISCC segment  142  is of comparatively low spectral radiosity at the spectral radiosity constituency of light absorbed by SF structure  242  because the light absorbed by SS segment  252  does not reach IF segment  254  so as to be reflected by ISCC segment  142  and included in the XRic light leaving segment  142 . XRic light reaching area  118  is usually of the same spectral radiosity constituency as XRic light directly leaving segment  142 . If XRic light leaving area  118  is the same in both OI structures  130  and  240 , XRic light leaving area  118  in structure  240  can be of considerably different spectral radiosity constituency than XRic light leaving area  118  in structure  130  because it lacks SF structure  242  and does not undergo such wavelength-dependent absorption. Insofar as undesirable, this situation is alleviated by choosing the light-absorption characteristics of structure  242  to significantly avoid absorbing light at the spectral radiosity constituency of XRic light directly leaving segment  142 . 
     Analogous to what occurs with AEic light, the circumstances differ somewhat with any XEic light emitted by ISCC segment  142 . Any component of XEic light leaving segment  142  at wavelength significantly absorbed by SF structure  242  is considerably attenuated before reaching print area  118  due to absorption in SS segment  252 . XEic light reaching area  118  can thus be of considerably different spectral radiosity constituency than XEic light directly leaving ISCC segment  142 . If XEic light leaving area  118  is the same in both OI structures  130  and  240 , XEic light leaving area  118  in structure  240  so as to leave IDVC portion  138  can be of considerably different spectral radiosity constituency than XEic light leaving area  118  so as to leave portion  138  in structure  130  because it lacks SF structure  242  and does not undergo such wavelength-dependent absorption. To the extent undesirable, this situation is alleviated by choosing the light-absorption characteristics of OI structure  240  to significantly avoid absorbing light at the spectral radiosity constituency of XEic light directly leaving ISCC segment  142 . 
     SF structure  242  functions as a color filter for significantly absorbing light of selected wavelength in an embodiment of OI structure  240  in which structure  242  strongly influences principal SF color A or/and changed SF color X. For this embodiment, total ATic light as it leaves ISCC structure  132  along interface  244  during the normal state is of wavelength for a color termed principal internal color ATic. Because SF structure  242  significantly absorbs light, ISCC structure  132  is not externally visible along interface  244  as principal internal color ATic during the normal state. Total XTic light as it leaves ISCC segment  142  along IF segment  254  during the changed state is of wavelength for a color termed changed internal color XTic. ISSC segment  142  is not externally visible along IF segment  254  as changed internal color XTic during the changed state. 
     A selected one of internal colors ATic and XTic is a principal comparatively light color LP. The remaining one of colors ATic and XTic is a principal comparatively dark color DP darker than light color LP. Lightness L* of light color LP is usually at least 70, preferably at least 80, more preferably at least 90. Lightness L* of dark color DP is usually no more than 30, preferably no more than 20, more preferably no more than 10. If principal internal color ATic is light color LP, principal SF color A is darker than light color LP due to the light absorption by SF structure  242  while changed SF color X may be darker than dark color DP depending on the characteristics of the light absorption by structure  242  and on the lightness of dark color DP. If changed internal color XTic is light color LP, changed SF color X is darker than light color LP while principal SF color A may be darker than dark color DP. Importantly, the colors embodying colors A and X can be significantly varied by changing the light absorption characteristics of structure  242  without changing ISCC structure  132 . 
     Different shades of the embodiments of colors A and X occurring in the absence of ARss light can be created by varying the reflection characteristics of SF structure  242 , specifically the wavelength and intensity characteristics of ARss light, without changing ISCC structure  132 . SF structure  242  thus strongly influences color A or/and color X. 
     The pressure spreading performable by SF structure  242  enables print area  118  to closely match OC area  116  in size, shape, and location along SF zone  112 . Structure  242  is a principal pressure-spreading structure. “PS” hereafter means pressure-spreading. Interface  244 , spaced apart from zone  112  so as to be inside OI structure  240 , is a principal internal PS surface. ISCC structure  132  is a principal pressure-sensitive CC structure because it is sensitive to the excess internal pressure produced by PS structure  242  along PS surface  244 . “PSCC” hereafter means pressure sensitive color-change. ISCC segment  142  is similarly a PSCC segment. 
     For the situation in which IDVC portion  138  temporarily appears as color X if the excess internal pressure along segment  254  meet the excess internal pressure criteria, an understanding of the benefits of pressure spreading on PSCC structure  132  is facilitated by first considering what occurs during an impact in similar OI structure  130  lacking PS structure  242  in the corresponding situation where portion  138  temporarily appears as color X if the impact meets the basic TH impact criteria. With reference to  FIGS. 6 b  and 6 c    respectively corresponding to  FIGS. 13 b  and 13 c   , the impact creates excess SF pressure along area  116 . The TH impact criteria which must be met for IDVC portion  138  to temporarily appear as color X in response to the impact and which determine the size, shape, and location of print area  118  along SF zone  112  largely become the above-described principal basic excess SF pressure criteria requiring that the excess SF pressure at a point along zone  112  equal or exceed a local TH value in order for that point to be a TH CM point and temporarily appear as color X. Since the excess SF pressure drops to zero along the perimeter of OC area  116 , print area  118  is located inside OC area  116  with the perimeters of areas  116  and  118  separated by perimeter band  120  which appears as color A during the changed state because the excess SF pressure at each point in band  120  is less than the local TH excess SF pressure value for that point. 
     Perimeter band  120  generally becomes smaller as the TH excess SF pressure values decrease. This improves the size, shape, and location matching between OC area  116  and print area  118 . However, reducing the TH excess SF pressure values makes it easier for color change to occur along SF zone  112  and can result in undesired color change. The area of band  120  usually cannot be reduced to essentially zero without introducing reliability difficulty into OI structure  130 . 
     Returning to  FIGS. 13 b  and 13 c   , PS structure  242  laterally spreads the excess SF pressure caused by the impact so that DP IF area  256  is laterally larger than OC area  116 . An annular band (not labeled) of internal PS surface  244  extends between the perimeters of IF area  256  and IF segment  254 . This band lies opposite a corresponding annular band (not separately indicated) of SF zone  112 . The excess internal pressure along IF area  256  reaches a maximum value within area  256  and drops to zero along its perimeter. This results in the excess internal pressure criteria not being met in the annular band between the perimeters of area  256  and IF segment  254 . The corresponding annular band of SF zone  112  appears as color A during the changed state. Because area  256  is laterally larger than oppositely situated OC area  116 , the size and shape of the annular band of zone  112  can be adjusted to achieve very close size, shape, and location matching between OC area  116  and print area  118 . In effect, the pressure spreading enables perimeter band  120  between areas  116  and  118  to be made quite small without introducing reliability difficulty into PSCC structure  132 . The same arises when IDVC portion  138  temporarily appears as color X if PSCC segment  142  is provided with the general CC control signal generated in response to the excess internal impact criteria being met and sometimes other impact criteria also being met. 
     Print area  118 , although shown as being smaller than OC area  116  in  FIGS. 13 b  and 13 c   , can be larger than it in OI structure  240 . The perimeters of areas  116  and  118  in structure  240  can variously cross each other. Print area  118  in structure  240  differs usually by no more than 20%, preferably by no more than 15%, more preferably by no more than 10%, even more preferably by no more than 5%, in area from OC area  116 , at least when total OC area  124  is in SF zone  112  as arises in  FIG. 13 b   . In  FIG. 13 c    where area  124  extends beyond zone  112 , the same percentages apply to an imaginary variation of structure  240  in which zone  112  is extended to encompass all of area  124 . 
     Turning to the protective function, SF structure  242  is located between ISCC structure  132  and the external environment. This shields structure  132  from the external environment. In particular, protective SF structure  242  is sufficiently thick to materially protect ISCC structure  132  from being damaged by most matter impacting, lying on, and/or moving along SF zone  112  and thereby serves as a protective structure. Protective structure  242 , which may be thicker than ISCC structure  132 , materially absorbs the shock of matter, including object  104 , impacting zone  112 . Part of the force exerted by object  104  dissipates in structure  242  so that the force exerted on DP IF area  256  due to the object impact is less, typically considerably less, than the force exerted by object  104  directly on OC area  116 . 
     SF structure  242  blocks at least 80%, preferably at least 90%, more preferably at least 95%, of UV radiation striking it. As a result, structure  242  materially protects ISCC structure  132  from being damaged by UV radiation. DP IF area  256 , which is larger than IF segment  254  when protective structure  242  performs pressure spreading, is usually closer to segment  254  in size if structure  242  performs the protective function but does not (significantly) perform the PS function. 
       FIGS. 14 a -14 c    (collectively “ FIG. 14 ”) illustrate an embodiment  260  of OI structure  240 . OI structure  260  is also an extension of OI structure  180  to include SF structure  242 . ISCC structure  132  here is formed with components  182  and  184  configured the same as in OI structure  180 . See  FIG. 14 a   . SF structure  242 , which meets IS component  182  along interface  244 , is here configured and operable the same as in OI structure  240 . 
     ISCC structure  132  here operates the same during the normal state as in OI structure  180  except that light leaving structure  132  via SF zone  112  in OI structure  180  leaves structure  132  via interface  244  here. Total ATcc light consists of ARcc light and any AEcc and ARsb light leaving CC component  184 . Total ATic light leaving IS component  182 , and thus structure  132 , consists of ARcc light passing through component  182 , any AEcc and ARsb light passing through it, and any ARis light reflected by it. Substantial parts of the ARcc light and any AEcc, ARis, and ARsb light pass through SF structure  242 . Including any ARss light reflected by structure  242 , A light is formed with ARcc light and any AEcc, ARss, ARis, and ARsb light normally leaving structure  242  and therefore VC region  106 . 
     The changed-state light processing in ISCC segment  142  here is essentially the same as in OI structure  180  except that light leaving segment  142  via print area  118  in structure  180  leaves segment  142  via IF segment  254  here. See  FIGS. 14 b  and 14 c   . IS segment  192  provides a principal general impact effect if the impact meets the basic TH impact criteria. The general impact effect is specifically provided in response to the excess internal pressure along IF segment  254  meeting the basic excess internal pressure criteria which implement the TH impact criteria. Total XTcc light consists of XRcc light and any XEcc and XRsb light leaving CC segment  194  in response (a) in some general OI embodiments to the general impact effect or (b) in other general OI embodiments to the general CC control signal generated in response to the effect sometimes dependent on other impact criteria also being met in those other embodiments. Total XTic light leaving IS segment  192 , and thus ISCC segment  142 , consists of XRcc light passing through segment  192 , any XEcc and XRsb light passing through it, and any ARis light reflected by it. Substantial parts of the XRcc light and any XEcc, ARis, and XRsb light pass through SS segment  252 . Including any ARss light reflected by segment  252 , X light is formed with XRcc light and any XEcc, ARss, ARis, and XRsb light leaving segment  252  and hence IDVC portion  138 . 
       FIGS. 15 a -15 c    (collectively “ FIG. 15 ”), illustrate an embodiment  270  of OI structure  260  and thus of OI structure  240 . OI structure  270  is also an extension of OI structure  200  to include SF structure  242 . See  FIG. 15 a   . ISCC structure  132  here is formed with IS component  182  and CC component  184  consisting of NA layer  204 , NE structure  224 , core layer  222 , FE structure  226 , and FA layer  206  configured the same as in OI structure  200 . SF structure  242 , which again meets component  182  along interface  244 , is here configured and operable the same as in OI structure  260  and thus the same as in OI structure  240 . 
     CC component  184  here operates the same during the normal state as in OI structure  200 . Total ATcc light consists of any ARab, AEab, ARfa, AEfa, ARna, and ARsb light leaving component  184 . IS component  182  here operates the same during the normal state as in structure  200  except that light leaving component  182  via SF zone  112  in structure  200  leaves component  182  via interface  244  here. Total ATic light normally leaving component  182 , and thus ISCC structure  132 , consists of any ARab, AEab, ARfa, AEfa, ARna, and ARsb light passing through component  182  and any ARis light reflected by it. 
     Substantial parts of any ARab, AEab, ARfa, AEfa, ARis, ARna, and ARsb light pass through SF structure  242 . Including any ARss light normally reflected by structure  242 , A light is formed with any ARab, AEab, ARfa, AEfa, ARss, ARis, ARna, and ARsb light normally leaving structure  242  and thus VC region  106 . The following normal-state relationships apply here to the extent that the indicated light species are present: ARab, ARfa, and ARna light form ARcc light; ARab light consists of ARcl, ARne, and ARfe light; AEab and AEfa light form AEcc light; and AEab light consists of AEcl light. 
     ID segments  214 ,  234 ,  232 ,  236 , and  216  of respective subcomponents  204 ,  224 ,  222 ,  226 , and  206  are not labeled in  FIG. 15 b    or  15   c  due to spacing limitations. See  FIG. 12 b    or  12   c  for identifying segments  214 ,  234 ,  232 ,  236 , and  216  in  FIG. 15 b    or  15   c . With reference to  FIGS. 15 b  and 15 c   , IS segment  192  again provides a principal general impact effect in response to the excess internal pressure along IF segment  254  meeting the basic excess internal pressure criteria which implement the basic TH impact criteria. The changed-state light processing in CC segment  194  here is then the same as in OI structure  200 . Total XTcc light consists of any XRab, XEab, XRfa, XEfa, XRna, and XRsb light leaving segment  194  in response (a) in some general OI embodiments to the general impact effect or (b) in the other general OI embodiments to the general CC control signal generated in response to the effect sometimes dependent on both the TH impact criteria and other criteria being met. The changed-state light processing in IS segment  192  here is the same as in structure  200  except that light leaving segment  192  via print area  118  in structure  200  leaves segment  192  via IF segment  254  here. Total XTic light leaving segment  192 , and thus ISCC segment  142 , consists of any XRab, XEab, XRfa, XEfa, XRna, and XRsb light passing through segment  192  and any ARis light reflected by it. 
     Substantial parts of any XRab, XEab, XRfa, XEfa, ARis, XRna, and XRsb light pass through SS segment  252 . Including any ARss light reflected by segment  252 , X light is formed with any XRab, XEab, ARfa, XEfa, XRss, ARis, XRna, and XRsb light normally leaving segment  252  and thus IDVC portion  138 . The general CC control signal to which core layer  222  responds as VC region  106  goes to the changed state can be generated by SF structure  242 , IS component  182 , or a portion, e.g., NA layer  204 , of CC component  184  in response to the pressure-sensitive general impact effect. The control signal can also be generated outside VC region  106 . The following changed-state relationships apply here to the extent that the indicated light species are present: XRab, XRfa, and XRna light form XRcc light; XRab light consists of XRcl, XRne, and XRfe light; XEab and XEfa light form XEcc light; and XEab light consists of XEcl light. 
     Object-Impact Structure Having Deformation-Controlled Extended Color-Change Duration 
       FIGS. 16 a -16 c    (collectively “ FIG. 16 ”) illustrate an extension  280  of OI structure  130  for which the duration of each temporary color change along print area  118  is extended in a pre-established deformation-controlled manner. OI structure  280  is configured the same as structure  130  except that VC region  106  here includes a principal duration-extension structure  282  extending from substructure  134  to meet ISCC structure  132  along a flat principal structure-structure interface  284  extending parallel to SF zone  112 . See  FIG. 16 a   . “DE” hereafter means duration-extension. 
     Light may pass through ISCC structure  132 . If so, DE structure  282  may normally reflect light, termed ARde light, which leaves it via interface  284 . If any light passes through structure  282  and strikes substructure  134 , substructure  134  may reflect ARsb light which passes in substantial part through structure  282 . The total light, termed ATde light, normally leaving structure  282  via interface  284  consists of any ARde and ARsb light. Substantial parts of any ARde and ARsb light pass through structure  132 . ARic light reflected by structure  132 , any AEic light emitted by it, and any ARde and ARsb light together normally leaving it, and thus VC region  106 , form A light. Each of ADic light and either ARic or AEic light is once again usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of A light. 
     VC region  106  deforms along SF DF area  122  in response to object  104  impacting OC area  116 , “DF” again meaning deformation. See  FIG. 16 b    or  16   c . Since SF zone  112  is a surface of ISCC structure  132  in OI structure  280 , ISCC structure  132  directly deforms along DF area  122 . If the TH impact criteria are met, i.e., if the SF deformation along area  122 , specifically print area  118 , meets the principal basic SF DF criteria embodying the principal basic TH impact criteria, the SF deformation causes IDVC portion  138  to temporarily appear as color X for base duration Δt drbs  as the changed state begins. More particularly, ISCC segment  142  cause portion  138  to change color in response to the SF deformation if the TH impact criteria are met. Base duration Δt drbs  is passively determined largely by the properties of the material in ISCC structure  132  operating in response to the SF deformation along area  122 . In the absence of DE structure  282 , CC duration Δt dr  would be automatic value Δt drau  equal to base duration Δt drbs . 
     DE structure  282  responds to the deformation along SF DF area  122 , and thus to the impact, by deforming along an ID principal internal DF area  288  of interface  284 . If the TH impact criteria are met, the internal deformation of ISCC structure  132  along ID internal DF area  288 , spaced apart from DF area  122  and located opposite it, causes IDVC portion  138  to further temporarily appear as color X for extension duration Δt drext  so that automatic duration Δt drau  is the sum of durations Δt drbs  and Δt drext . Subject to the TH impact criteria being met, ISCC segment  142  specifically responds to the internal deformation along DF area  288  by causing portion  138  to continue temporarily appearing as color X. Extension duration Δt drext  is passively determined largely by the properties of the material in DE structure  282  and ISCC structure  132  operating in response to the internal deformation along area  288 . 
     Also, item  292  in  FIGS. 16 b  and 16 c    is the ID segment of DE structure  282  present in IDVC portion  138 . Item  294  is the ID segment of interface  284  present in portion  138 . ID IF segment  294  at least partly encompasses, and at least mostly outwardly conforms to, internal DF area  288 .  FIGS. 16 b  and 16 c    depict area  288  as being larger than segment  294  because the perimeters of area  288  and segment  294  are usually separated by a band  298  in which the deformation along interface  284  is insufficient to meet the TH impact criteria. Internal change sufficient to cause portion  138  to appear as color X occurs along segment  294  but usually not along perimeter band  298 . Hence, ISCC segment  142  specifically causes portion  138  to continue its color change in response to the deformation along segment  294 . 
     ISCC structure  132  here can be embodied in many ways including as a single material consisting of IS CR or CE material which temporarily reflects X light due to the deformation at DF areas  122  and  288  caused by the impact. The deformation along area  122  or  288  can be impact-caused compressive deformation or impact-caused vibrational deformation whose amplitude rapidly decreases largely to zero. If vibrational deformation along area  122  partly or fully causes structure  132  to temporarily reflect X light during base duration Δt drbs , vibrational deformation along internal area  288  usually partly or fully causes structure  132  to temporarily reflect X light during extension duration Δt drext . 
     ID DE segment  292  may reflect light, termed XRde light, which leaves it via IF segment  294  during the changed state. XRde light can be the same as, or significantly differ from, ARde light depending on how the light processing in IDVC portion  138  during the changed state differs from the light processing in VC region  106  during the normal state. If any light passes through DE segment  292  so as to strike substructure  134  along portion  138 , substructure  134  may reflect XRsb light which passes in substantial part through segment  292 . The total light, termed XTde light, temporarily leaving segment  292  via IF segment  294  consists of any XRde and XRsb light. Substantial parts of any XRde and XRsb light pass through ISCC segment  142 . XRic light reflected by segment  142 , any XEic light emitted by it, and any XRde and XRsb light together leaving it, and thus portion  138 , form X light. Each of XDic light and either XRic or XEic light is once again usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of X light. 
       FIGS. 17 a -17 c    (collectively “ FIG. 17 ”) illustrate an extension  300  of OI structure  200 , and hence of OI structure  180 , for which the duration of each color change along print area  118  is extended in a pre-established deformation-controlled manner. VC region  106  of OI structure  300  contains a principal DE structure  302  located between overlying IS component  182  and underlying CC component  184  so that they are spaced apart from each other. See  FIG. 17 a   . Direct electrical connections between components  182  and  184  in structure  200  are generally replaced here with electrical connections passing through DE structure  302 . As in OI structure  200 , CC component  184  here consists of auxiliary layers  204  and  206  and assembly  202  formed with core layer  222  and electrode structures  224  and  226 . DE structure  302  meets (a) IS component  182  along a flat principal near light-transmission interface  304  extending parallel to SF zone  112  and (b) CC component  184 , specifically NA layer  204 , along a flat principal far light-transmission interface  306  likewise extending parallel to zone  112  and thus to interface  304 . 
     CC component  184  here operates the same during the normal state as in OI structure  200  except that light leaving component  184  via interface  186  in structure  200  leaves component  184  via interface  306  here. Total ATcc light consists of ARcc light reflected by component  184 , any AEcc light emitted by it, and any ARsb light passing through it. The following normal-state relationships again apply to the extent that the indicated light species are present: ARab, ARfa, and ARna light form ARcc light; ARab light consists of ARcl, ARne, and ARfe light; AEab and AEfa light form AEcc light; and AEab light consists of AEcl light. 
     Substantial parts of the ARcc light and any AEcc and ARsb light pass through DE structure  302 . Structure  302  may normally reflect ARde light. Total ATde light leaving structure  302  via interface  304  consists of ARcc light and any AEcc, ARde, and ARsb light. Substantial parts of the ARcc light and any AEcc, ARde, and ARsb light pass through IS component  182 . Including any ARis light reflected by component  182 , A light is formed with ARcc light and any AEcc, ARis, ARde, and ARsb light normally leaving component  182  and thus VC region  106 . Even though components  182  and  184  are spaced apart from each other here, ADcc light and any ARis light still form ADic light consisting of ARic light and any AEic light for which ARic light is formed with ARcc light and any ARis light while AEic light is formed with any AEcc light. Each of ADcc light and either ARcc or AEcc light is again usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of each of A and ADic light. 
     IS component  182  deforms along SF DF area  122  in response to the impact. See  FIG. 17 b    or  17   c . If the TH impact criteria are met, i.e., if the deformation along area  122 , specifically print area  118 , meets the principal basic SF DF criteria embodying the principal basic TH impact criteria, component  182 , largely IS segment  192 , provides the general impact effect, termed the principal general first impact effect. CC segment  194  responds to the principal general first impact effect by causing IDVC portion  138  to temporarily appear as color X for base duration Δt drbs , thereby beginning the changed state. Duration Δt drbs  is passively determined largely by the properties of (a) the material in component  182  operating in response to the SF deformation along SF DF area  122  and (b) the material in CC component  184  operating in response to the first general impact effect. 
     DE structure  302  responds to the deformation along SF DF area  122 , and thus to the impact, by deforming along an ID principal internal DF area  308  of interface  304 . Since interface  304  is also a surface of IS component  182 , the deformation of structure  302  along ID internal DF area  308 , spaced apart from SF DF area  122  and located opposite it, causes component  182  to deform along area  308 . If the TH impact criteria are met, component  182 , again largely IS segment  192 , responds to the internal deformation along area  308  by providing another impact effect, termed the principal general second impact effect, slightly after providing the first general impact effect. CC segment  194  responds to the principal general second impact effect by causing IDVC portion  138  to further temporarily appear as color X for extension duration Δt drext . Automatic duration Δt drau  is again extended from base duration Δt drbs  to the sum of durations Δt drbs  and Δt drext . Duration Δt drext  is passively determined largely by the properties of (a) the material in structure  302  and IS component  182  operating in response to the internal deformation along area  308  and/or (b) the material in CC component  184  operating in response to the second general impact effect. 
     Also, item  312  in  FIGS. 17 b  and 17 c    is the ID segment of DE structure  302  present in IDVC portion  138 . Items  314  and  316  respectively are the ID segments of interfaces  304  and  306  present in portion  138 . ID IF segment  314  at least partly laterally encompasses, and at least mostly outwardly conforms to, internal DF area  308 .  FIGS. 17 b  and 17 c    depict area  308  as being larger than IF segment  314  because the perimeters of area  308  and segment  314  are usually separated by a band  318  in which the deformation along interface  304  is insufficient to meet the TH impact criteria. Internal change sufficient to cause portion  138  to appear as color X occurs along segment  314  but usually not along perimeter band  318 . Accordingly, ISCC segment  142  specifically causes portion  138  to continue its color change in response to the deformation along segment  314 . 
     Each general impact effect provided by IS segment  192  is typically an electrical effect consisting of one or more electrical signals supplied to CC segment  194  via one or more of the above-mentioned electrical connections through DE structure  302 . The deformation along DF area  122  or  308  can be impact-caused compressive deformation or impact-caused vibrational deformation whose amplitude eventually decreases largely to zero. 
     The changed-state light processing in CC segment  194  here is the same as in OI structure  200  except that light leaving segment  194  via IF segment  196  in structure  200  leaves it via ID IF segment  316  here. Total XTcc light consists of XRcc light reflected by CC segment  194 , any XEcc light emitted by it, and any XRsb light passing through it. The following changed-state relationships again apply to the extent that the indicated light species are present: XRab, XRfa, and XRna light form XRcc light; XRab light consists of XRcl, XRne, and XRfe light; XEab and XEfa light form XEcc light; and XEab light consists of XEcl light. 
     Substantial parts of the XRcc light and any XEcc and XRsb light pass through ID DE segment  312 . If ARde light is reflected by DE structure  302  during the normal state, segment  312  reflects ARde light during the changed state. Total XTde light leaving segment  312  via IF segment  314  consists of XRcc light and any XEcc, ARde, and XRsb light. Substantial parts of the XRcc light and any XEcc, ARde, and XRsb light pass through IS segment  192 . Including any ARis light reflected by segment  192 , X light is formed with XRcc light and any XEcc, ARis, ARde, and XRsb light leaving segment  192  and thus IDVC portion  138 . The changed-state light processing is the same during both of durations Δt drbs  and Δt drext . 
     Additionally, XDcc light and any ARis light still form XDic light consisting of XRic light and any XEic light for which XRic light is formed with XRcc light and any ARis light while XEic light is formed with any XEcc light. Each of XDcc light and either XRcc or XEcc light is again usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of each of X and XDic light. 
       FIGS. 18 a -18 c    (collectively “ FIG. 18 ”) illustrate an extension  320  of both OI structure  240  and OI structure  280 . OI structure  320  is configured the same as structure  280  except that VC region  106  here contains SF structure  242  extending from SF zone  112  to ISCC structure  132  to meet it along interface  244 . See  FIG. 18 a   . Structure  242  here is configured and operable the same as in OI structure  240 . 
     ISCC structure  132  and DE structure  282  here operate the same during the normal state as in OI structure  280  except that light leaving ISCC structure  132  via SF zone  112  in OI structure  280  leaves structure  132  via interface  244  here. Total ATic light consists of ARic light reflected by structure  132 , any AEic light emitted by it, and any ARde and ARsb light passing through it. Substantial parts of the ARic light and any AEic, ARde, and ARsb light pass through SF structure  242 . Including any ARss light normally reflected by structure  242 , A light is formed with ARic light and any AEic, ARss, ARde and ARsb light normally leaving structure  242  and thus VC region  106 . Again, each of ADic light and either ARic or AEic light is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of A light. 
     SF structure  242  here deforms along SF DF area  122  in response to the impact. See  FIG. 18 b    or  18   c . The impact also creates excess SF pressure along OC area  116 . The excess SF pressure is transmitted through structure  242  to produce excess internal pressure along DP IF area  256 , causing it to deform. Because interface  244  is a surface of ISCC structure  132  here, structure  132  deforms along area  256 . If the TH impact criteria are met, i.e., if the internal deformation along area  256 , specifically IF segment  254 , meets principal basic internal DF criteria embodying the principal basic TH impact criteria, the internal deformation causes IDVC portion  138  to temporarily appear as color X for base duration Δt drbs  as the changed state begins. More particularly, ISCC segment  142  responds to the internal deformation along area  256 , and thus to the impact-caused SF deformation along area  122 , by causing portion  138  to begin temporarily appearing as color X if the TH impact criteria are met. Duration Δt drbs  is passively determined largely by the properties of the material in SF structure  242  and ISCC structure  132  operating in response to the internal deformation along area  256 . 
     DE structure  282  here responds to the internal deformation along DP IF area  256  by deforming along internal DF area  288  of interface  284 . Since interface  284  is a surface of ISCC structure  132 , the deformation of DE structure  282  along area  288  causes ISCC structure  132  to deform along area  288 . If the TH impact criteria are met, the internal deformation of structure  132  along area  288 , specifically IF segment  294 , causes IDVC portion  138  to further temporarily appear as color X for extension duration Δt drext . Subject to the TH impact criteria being met, ISCC segment  142  specifically responds to the internal deformation along area  288 , and thus to the impact, by causing portion  138  to continue temporarily appearing as color X. Automatic duration Δt drau  lengthens to Δt drbs +Δt drext . Duration Δt drext  is passively determined largely by the properties of the material in SF structure  242  and ISCC structure  132  operating in response to the internal deformation along area  288 . Internal change sufficient to cause portion  138  to appear as color X again occurs along IF segment  294  but usually not along perimeter band  298  where the deformation is insufficient to meet the TH impact criteria. Consequently, ISCC segment  142  specifically causes portion  138  to continue its color change in response to the deformation along segment  294 . 
     The changed-state light processing in ISCC segment  142  and DE segment  292  here is the same as in OI structure  280  except that light leaving ISCC segment  142  via print area  118  in structure  280  leaves segment  142  via IF segment  254  here. Total XTic light consists of XRic light reflected by ISCC segment  142 , any XEic light emitted by it, and any XRde and XRsb light passing through it. Substantial parts of the XRic light and any XEic, XRde, and XRsb light pass through SS segment  252 . Including any ARss light reflected by segment  252 , X light is formed with XRic light and any XEic, ARss, XRde and XRsb light temporarily leaving segment  252  and thus IDVC portion  138 . Again, each of XDic light and either XRic or XEic light is usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of X light. 
       FIGS. 19 a -19 c    (collectively “ FIG. 19 ”) illustrate an extension  330  of both OI structure  270  and OI structure  300 . OI structure  330  is configured and operable the same as structure  300  except that VC region  106  here contains SF structure  242  extending from SF zone  112  to ISCC structure  132  to meet it, specifically IS component  182 , along interface  244 . See  FIG. 19 a   . SF structure  242  here is configured and operable the same as in OI structure  270  and thus the same as in OI structure  240 . 
     IS component  182 , DE structure  302 , and CC component  184  here operate the same during the normal state as in OI structure  300  except that light leaving IS component  182  via SF zone  112  in structure  300  leaves component  182  via interface  244  here. Total ATcc light consists of ARcc light reflected by CC component  184 , any AEcc light emitted by it, and any ARsb light passing through it. Total ATic light leaving IS component  182 , and therefore ISCC structure  132 , consists of ARcc light passing through component  182  and DE structure  302 , any AEcc and ARsb light passing through component  182  and structure  302 , any ARde light passing through component  182 , and any ARis light reflected by it. Substantial parts of the ARcc light and any AEcc, ARis, ARde, and ARsb light pass through SF structure  242 . Including any ARss light reflected by structure  242 , A light is formed with ARcc light and any AEcc, ARss, ARis, ARde, and ARsb light normally leaving structure  242  and thus VC region  106 . Each of ADcc light and either ARcc or AEcc light is once again usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of each of A and ADic light. 
     SF structure  242  here deforms along SF DF area  122  in response to the impact. See  FIG. 19 b    or  19   c . The attendant excess SF pressure along OC area  116  is transmitted through structure  242  to produce excess internal pressure along DP IF area  256 , causing it to deform. Because interface  244  is a surface of IS component  182  here, it deforms along area  256 . If the TH impact criteria are met, i.e., if the internal deformation along area  256 , specifically IF segment  254 , meets principal basic internal DF criteria embodying the principal basic TH impact criteria, component  182 , likewise largely IS segment  192 , provides the general impact effect, again termed the principal general first impact effect. CC segment  194  responds to the principal general first impact effect by causing IDVC portion  138  to temporarily appear as color X for base duration Δt drbs , thereby beginning the changed state. Duration Δt drbs  is passively determined largely by the properties of (a) the material in structure  242  and component  182  operating in response to the internal deformation along area  256  and (b) the material in CC component  184  operating in response to the first general impact effect. 
     DE structure  302  here responds to the internal deformation along DP IF area  256  by deforming along internal DF area  308  of interface  304 . Because interface  304  is a surface of IS component  182 , the deformation of structure  302  along area  308  causes component  182  to deform. If the TH impact criteria are met, component  182 , largely IS segment  192 , provides another impact effect, again termed the principal general second impact effect. CC segment  194  responds to the principal general second impact effect by further temporarily appearing as color X for extension duration Δt drext . Automatic duration Δt drau  is again lengthened to Δt drbs +Δt drext . Duration Δt drext  is passively determined by the properties of (a) the material in structure  302  and component  182  operating in response to the internal deformation along area  308  and/or (b) the material in CC component  184  operating in response to the second general impact effect. Internal change sufficient to cause IDVC portion  138  to appear as color X again occurs along IF segment  314  but usually not along perimeter band  318  where the deformation is insufficient to meet the TH impact criteria. Hence, ISCC segment  142  specifically causes portion  138  to continue its color change in response to the deformation along segment  314 . 
     The changed-state light processing in IS segment  192 , DE segment  312 , and CC segment  194  here is the same as in OI structure  300  except that light leaving IS segment  192  via print area  118  in structure  300  leaves segment  192  via IF segment  254  here. Total XTcc light consists of XRcc light reflected by CC segment  194 , any XEcc light emitted by it, and any XRsb light passing through it. Total XTic light leaving IS segment  192 , and thus ISCC segment  142 , consists of XRcc light passing through IS segment  192  and DE segment  312 , any XEcc and XRsb light passing through segments  192  and  312 , any ARde light passing through IS segment  192 , and any ARis light reflected by it. Substantial parts of the XRcc light and any XEcc, ARis, ARde, and XRsb light pass through SS segment  252 . Including any ARss light reflected by segment  252 , X light is formed with XRcc light and any XEcc, ARss, ARis, ARde and XRsb light temporarily leaving segment  252  and therefore IDVC portion  138 . Each of XDcc light and either XRcc or XEcc light is once again usually a majority component, preferably a 75% majority component, more preferably a 90% majority component, of each of X and XDic light. 
     Equation-Form Summary of Light Relationships 
     Given below is an equation-form summary of the potential light relationships along SF zone  112  during the normal and changed states for an embodiment of OI structure  100  in which VC region  106  contains (a) ISCC structure  132  formed with IS component  182  and CC component  184  consisting of NA layer  204 , FA layer  206 , and assembly  202  consisting of subcomponents  222 ,  224 , and  226 , (b) possibly SF structure  242 , and (c) possibly DE structure  282  or  302  where the alphabetic notation used in these equations means the light described above using the same notation, e.g., “A” and “XDcc” in the equations respectively mean A light and XDcc light and where “XRde/ARde” means “XRde” for DE segment  292  and “ARde” for DE segment  312 . Each term in these equations is the normalized spectral radiosity for the light species identified by that term. Light absorption by a region, e.g., SF structure  242  or SS segment  252 , situated between ISCC structure  132  and zone  112  is ignored with regard to emitted light. 
     I. Equations for Normal State: 
     SF structure  242 , DE structure  282  or  302 , ISCC structure  132 , and substructure  134 :
 
 A=ARss+ARde+ADic+ARsb   (B1)
 
where ADic=ARic+AEic
 
ISCC structure  132  consisting of IS component  182  and CC component  184 :
 
 ADic=ARis+ADcc   (B2)
 
where ADcc=ARcc+AEcc
 
SF structure  242 , IS component  182 , DE structure  282  or  302 , CC component  184 , and substructure  134 :
 
 A=ARss+ARis+ARde+ADcc+ARsb   (B3)
 
CC component  184  consisting of NA layer  204 , assembly  202 , and FA layer  206 :
 
 ADcc=ARna+ADab+ADfa   (B4)
 
where ADab=ARab+AEab, and ADfa=ARfa+AEfa
 
Assembly  202  consisting of NE structure  224 , core layer  222 , and FE structure  226 :
 
 ADab=ARab+AEab=ARne+ADcl+ARfe   (B5)
 
where ARab=ARne+ARcl+ARfe, AEab=AEcl, and ADcl=ARcl+AEcl
 
Combination of normal-state equations:
 
 A=ARss+ARde+ARis+ARna+ARne+ARcl+AEcl+ARfe+ARfa+AEfa+ARsb   (B6)
 
     II. Equations for Changed State: 
     SS segment  252 , DE segment  292  or  312 , ISCC segment  142 , and segment of substructure  134  along IDVC portion  138 :
 
 X=ARss+XRde/ARde+XDic+XRsb   (B7)
 
where XDic=XRic+XEic
 
ISCC segment  142  consisting of IS segment  192  and CC segment  194 :
 
 XDic=ARis+XDcc   (B8)
 
where XDcc=XRcc+XEcc
 
SS segment  252 , IS segment  192 , DE segment  292  or  312 , CC segment  194 , and segment of substructure  134  along IDVC portion  138 :
 
 X=ARss+ARis+XRde/ARde+XDcc+XRsb   (B9)
 
CC segment  194  consisting of NA segment  214 , AB segment  212 , and FA segment  216 :
 
 XDcc=XRna+XDab+XDfa   (B10)
 
where XDab=XRab+XEab, and XDfa=XRfa+XEfa
 
AB segment  212  consisting of NE segment  234 , core segment  232 , and FE segment  236 :
 
 XDab=XRab+XEab=XRne+XDcl+XRfe   (B11)
 
where XRab=XRne+XRcl+XRfe, XEab=XEcl, and XDcl=XRcl+XEcl
 
Combination of changed-state equations:
 
 X=ARss+XRde/ARde+ARis+XRna+XRne+XRcl+XEcl+XRfe+XRfa+XEfa+XRsb   (B12)
 
     Light not present in an embodiment of OI structure  100  is to be deleted from these equations in particularizing them to that embodiment. The radiosities of ARss, ARis, ARde, ARna, ARne, ARfe, ARsb, XRna, XRne, XRfe, and XRsb light are preferably as low as feasible. This provides flexibility in choosing colors A and X and their components. The radiosities of these eleven light species can variously be set to zero so as to correspondingly eliminate them from the above equations and the description of OI structure  100  and its embodiments to provide simplifying approximations for design purposes. 
     Transmissivity Specifications 
     The transmissivity (or transmittance) of (a) SF structure  242  (if present) at one or more thickness locations along it to light incident perpendicularly on SF zone  112  at at least wavelengths of ADic and XDic light for them respectively being majority components of A and X light, (b) IS component  182  at one or more thickness locations along it to light incident perpendicularly on zone  112  at at least wavelengths of ADcc and XDcc light for them respectively being majority components of A and X light, (c) DE structure  302  (if present) at one or more thickness locations along it to light incident perpendicularly on zone  112  at at least wavelengths of ADab, ADfa, XDab, and XDfa to the extent present for either ADab or ADfa light being a majority component of A light and for either XDab or XDfa light being a majority component of X light, (d) NA layer  204  (if present) at one or more thickness locations along it to light incident perpendicularly on zone  112  at at least wavelengths of ADab, ADfa, XDab, and XDfa light to the extent present for either ADab or ADfa light being a majority component of A light and for either XDab or XDfa light being a majority component of X light, and (e) NE structure  224  at one or more thickness locations along it to light incident perpendicularly on zone  112  at at least wavelengths of ADcl, ADfa, XDcl, and XDfa light to the extent present for either ADcl or ADfa light being a majority component of A light and for either XDcl or XDfa light being a majority component of X light is usually at least 40%, preferably at least 60%, more preferably at least 80%, even more preferably at least 90%, yet further preferably at least 95%. 
     The composite transmissivity of (a) the combination of SF structure  242  (if present) and IS component  182  at one or more thickness locations along that combination to light incident perpendicularly on SF zone  112  at at least wavelengths of ADcc and XDcc light, (b) the combination of structure  242  (if present), component  182 , and DE structure  302  (if present) at one or more thickness locations along that combination to light incident perpendicularly on zone  112  at at least wavelengths of ADab, ADfa, XDab, and XDfa light to the extent present, (c) the combination of structure  242  (if present), component  182 , and NA layer  204  (if present) at one or more thickness locations along that combination to light incident perpendicularly on zone  112  at at least wavelengths of ADab, ADfa, XDab, and XDfa light to the extent present, and (d) the combination of structure  242  (if present), component  182 , layer  204  (if present), and NE structure  224  at one or more thickness locations along that combination to light incident perpendicularly on zone  112  at at least wavelengths of ADcl, ADfa, XDcl, and XDfa light to the extent present is usually at least 30%, preferably at least 50%, more preferably at least 70%, even more preferably at least 80%, yet further preferably at least 90%. 
     Some of the present OI structures may be embodied to allow light to pass through one or more thickness locations of assembly  202  at certain times but not at other times during regular operation. Light then passes through one or more corresponding thickness locations of core layer  222  and FE structure  226  at certain times but not at other times. When such an assembly or core/FE-structure thickness location is light transmissive, the transmissivity of each of assembly  202 , layer  222 , and structure  226  to light incident perpendicularly on SF zone  112  at at least wavelengths of ADfa and XDfa light for either ARfa or ARfe light being a majority component of A light and for either XRfa or XRfe light being a majority component of X light is usually at least 60%, preferably at least 70%, more preferably at least 80%, even more preferably at least 90%, yet further preferably at least 95%, along that thickness location. The composite transmissivity of the combination of SF structure  242  (if present), IS component  182 , NA layer  204  (if present), and assembly  202  or the combination of structure  242  (if present), component  182 , layer  204  (if present), NE structure  224 , core layer  222 , and FE structure  226  to light incident perpendicularly on zone  112  at at least wavelengths of ADfa and XDfa light is usually at least 30%, preferably at least 50%, more preferably at least 70%, even more preferably at least 80%, yet further preferably at least 90%, along such an assembly or core thickness location when it is light transmissive. 
     Each component of each of the preceding light species for which a transmissivity specification is given above also meets that transmissivity specification. 
     Manufacture of Object-Impact Structure 
     OI structure  100 , including each embodiment  130 ,  180 ,  200 ,  240 ,  260 ,  270 ,  280 ,  300 ,  320 , or  330 , can be manufactured in various ways. In one manufacturing process, the materials of VC region  106  and FC region  108  are deposited on substructure  134 . In another manufacturing process, the material of one of color regions  106  and  108  is deposited on substructure  134 , and the other of regions  106  and  108  is formed separately and then attached to substructure  134 . In a further manufacturing process, regions  106  and  108  are formed separately and later attached to substructure  134 . Where feasible, the materials of regions  106  and  108  consist of polymer in order to provide them with impact resistance and bending flexibility. 
     In each manufacturing process where color region  106  or  108  is formed separately, region  106  or  108  may be fabricated as a relatively rigid structure or as a significantly bendable structure capable of, e.g., being rolled on substructure  134 . In each manufacturing process where VC region  106  consists of two or more subregions, such as components  182  and  184 , one of the subregions is typically initially fabricated. Each other subregion is then typically formed over the initially fabricated subregion. 
       FIGS. 20 a  and 20 b    present side cross sections of a more easily manufacturable variation  340  of OI structure  100 . OI structure  340  is configured the same as OI structure  130  except that structure  340  lacks FC region  108 . Instead, OI substructure  134  is externally exposed to the side(s) of VC region  106 . The absence of region  108  in structure  340  enables it to be manufactured more easily than structure  100 . 
     The surface of the exposed portion of substructure  134  is indicated as item  342  and is termed the exposed substructure SF zone. Due to the absence of FC region  108 , VC region  106  is externally exposed along a principal side SF zone  344  extending from VC SF zone  112  to exposed substructure SF zone  342 . Side SF zone  344  is shown in  FIGS. 20 a  and 20 b    as being flat and extending perpendicular to SF zones  112  and  342 . However, zone  344  can be significantly curved. Also, even if zone  344  is flat, it can extend significantly non-perpendicular to zones  112  and  342 . Zones  112 ,  342 , and  344  form surface  102  here. 
     Substructure  134  appears along substructure SF zone  342  as a substructure color A″. VC region  106  appears alongside SF zone  344  as a side color A′″. Each color A″ or A′″ is often the same as, but can differ significantly from, color A. If region  106  consists of multiple subregions extending to zone  344 , color A′″ can be a group of different colors. Alternatively, region  106  may include a generally homogeneous layer (not shown) whose outer surface largely forms zone  344  so that color A′″ is usually a single color often the same as color A. 
     VC region  106  here operates the same as in OI structure  130 .  FIG. 20 a   , corresponding to  FIG. 6 a   , shows how OI structure  340  normally appears.  FIG. 20 b   , corresponding to  FIG. 6 b   , presents an example in which object  104  contacts surface  102  fully within SF zone  112 . 
       FIGS. 21 a  and 21 b    present side cross sections of an embodiment  350  of OI structure  340  and thus a more easily manufacturable variation of OI structure  100 . ISCC structure  132  here consists of IS component  182  and CC component  184  formed with auxiliary layers  204  and  206  and assembly  202  consisting of subcomponents  224 ,  222 , and  226  arranged as in OI structure  200 . 
     VC region  106  here operates the same as in OI structure  200 .  FIG. 21 a   , corresponding to  FIG. 12 a   , shows how OI structure  350  normally appears.  FIG. 21 b   , corresponding to  FIG. 12 b   , presents an example in which object  104  contacts surface  102  fully within SF zone  112 . ID segments  214 ,  234 ,  232 ,  236 , and  216  of respective subcomponents  204 ,  224 ,  222 ,  226 , and  206  are not labeled in  FIG. 21 b    due to spacing limitations. See  FIG. 12 b    for identifying segments  214 ,  234 ,  232 ,  236 , and  216  in  FIG. 21   b.    
     Analogous to OI structures  340  and  350 , other more easily manufacturable variations of OI structure  100  are configured the same as OI structures  180 ,  200 ,  240 ,  260 ,  270 ,  280 ,  300 ,  320 , and  330  except that each of these other variations lacks FC region  108 . VC region  106  in each such variation of structure  180 ,  200 ,  240 ,  260 ,  270 ,  280 ,  300 ,  320 , or  330  operates the same as in that OI structure. Structures  340  and  350  and these other variations of structure  100  are suitable for applications in which region  106  is sufficiently thin that the distance from SF zone  112  to substructure SF zone  342  does not significantly affect structure usage. 
     A wedge is optionally placed alongside SF zone  344  to produce a relatively gradual transition from SF zone  112  to substructure SF zone  342  if the distance from zone  112  to zone  342  would detrimentally affect structure usage. The wedge dimension along zone  342  usually exceeds the wedge dimension along zone  344 . The wedge can be of roughly right triangular cross section with the longest surface extending approximately from zone  342  to the intersection of zones  112  and  344 . The wedge can be truncated slightly where the longest surface would otherwise meet zone  342 . 
     A removable protective cover can be placed over SF zone  112  of each of OI structures  180 ,  200 ,  240 ,  260 ,  270 ,  280 ,  300 ,  320 ,  330 ,  340 , and  350 , including the wedge-containing variations, when that OI structure is not in use for reducing damage that it would otherwise incur if not so protected. The protective cover is removed before the OI structure is used and reinstalled after use is completed. 
     If the protective cover could be a safety risk, each OI structure  180 ,  200 ,  240 ,  260 ,  270 ,  280 ,  300 ,  320 , or  330  is mounted in a cavity along surface  102  so that the exposed surface of the cover is approximately coplanar with surface  102  along the cavity opening. SF zone  112  then lies below the cavity opening at least when the OI structure is not in use. Although zone  112  can remain below the cavity opening when the OI structure is in use, the OI structure is preferably provided with apparatus, usually located at least partly along substructure  134 , for enabling the OI structure to be moved toward the cavity opening so that zone  112  is approximately coplanar with surface  102  along the cavity opening when the OI structure is in use. The cover is removed shortly before or after the movement is performed. After usage is complete, the OI structure is returned to the cavity, and the cover is reinstalled over the OI structure. 
     Object-Impact Structure with Print Area at Least Partly Around Unchanged Area 
       FIGS. 5 b  and 5 c    present, as described above, examples of object  104  impacting OC area  116  in OI structure  100  such that print area  118  consists of the area within perimeter band  120 . In contrast,  FIGS. 22 a  and 22 b    depict what occurs along surface  102  of structure  100  when object  104  contacts surface  102  such that area  118  lies at least partly around a generally unchanged area  360  of SF zone  112 . Area  118  in  FIGS. 22 a  and 22 b    has an outer perimeter and an inner perimeter relative to the area&#39;s center. VC region  106  appears along unchanged area  360  as color A, rather than as color X, when the IDVC portion ( 138 ) temporarily appears as color X. 
     Unchanged area  360  can arise due to various phenomena such as the shape of object  104 , the momentum with which it impacts SF zone  112 , and deformation that it may undergo in impacting zone  112 . If object  104  has a depression along its outer surface at the location where it contacts zone  112 , area  360  can arise if the momentum of the impact is insufficient to cause the entire surface of the depression to contact zone  112  with sufficient force to meet the principal TH impact criteria. Deformation incurred by object  104  in impacting zone  112  can be of such a nature as to result in area  360 . 
       FIG. 22 a   , analogous to  FIG. 5 b   , presents an example in which object  104  impacts surface  102  fully within VC SF zone  112 . Print area  118  in  FIG. 22 a    fully surrounds unchanged area  360  and is shaped like a fully annular band. Area  118  in  FIG. 22 a    thus fully outwardly conforms to OC area  116  but does not fully inwardly conform to it. Areas  116  and  118  are, nonetheless, largely concentric. 
       FIG. 22 b   , analogous to  FIG. 5 c   , presents an example in which object  104  contacts surface  102  partly within VC SF zone  112  and partly within FC SF zone  114  in the same impact. In this example, print area  118  lies partly around unchanged area  360  and is shaped like a partially annular band. With OC area  116  extending along part of the SF edge of interface  110  here, print area  118  extends along only a fraction of that SF edge interface part. Area  118  in  FIG. 22 b    outwardly conforms mostly, but not fully, to OC area  116  and does not inwardly conform mostly to it. Areas  116  and  118  here are largely concentric. 
       FIGS. 23 a  and 23 b    respectively corresponding to  FIGS. 22 a  and 22 b    are side cross sections illustrating what occurs in embodiment  130  of OI structure  100  when object  104  contacts surface  102  so that print area  118  lies at least partly around unchanged area  360  of VC SF zone  112 . The presence of area  360  causes IDVC portion  138  to have a shape matching that of print area  118 . Hence, portion  138  is shaped like a full hollow cylinder in  FIG. 23 a    and like a partial hollow cylinder in  FIG. 23 b   . Each of OC areas  116  and  124  and SF DF area  122  is shaped like a fully annular band in  FIG. 23 a   . In  FIG. 23 b   , each of areas  116  and  122  and OC area  126  is shaped like a partially annular band while total OC area  124  is shaped like a fully annular band. Portion  138  and areas  116 ,  122 , and  124  and, when present, area  126  have the same shapes in embodiments  180 ,  200 ,  240 ,  260 ,  270 ,  280 ,  300 ,  320 , and  330  of structure  100 . 
     Configurations of Impact-Sensitive Color-Change Structure 
       FIGS. 24 a  and 24 b    depict two embodiments of ISCC structure  132  suitable for OI structure  180 ,  200 ,  260 ,  270 ,  300 , or  330 . Each electrical effect mentioned below consists of one or more electrical signals. In  FIG. 24 a   , IS component  182  contains piezoelectric structure  370 . For OI structure  180 ,  200 ,  260 , or  270 , the segment of piezoelectric structure  370  in IS segment  192  provides the general impact effect as an electrical effect in response to pressure, specifically excess SF pressure, of object  104  impacting OC area  116  if the impact meets the TH impact criteria. The electrical effect is supplied from structure  370  along an electrical path  372  to CC component  184 , specifically CC segment  194 . 
     For OI structure  300  or  330 , the segment of piezoelectric structure  370  in IS segment  192  provides the first general impact effect as an electrical effect in response to deformation along SF DF area  122  due to pressure, specifically excess SF pressure, caused by object  104  impacting OC area  116 . The segment of structure  370  in segment  192  similarly provides the second general impact effect as an electrical effect in response to deformation along internal DF area  308  caused by pressure, specifically excess internal pressure, exerted by DE structure  302  on area  308  due to the impact. Both electrical effects are supplied along path  372  to CC segment  194 . 
     IS component  182  in  FIG. 24 b    contains piezoelectric structure  374  and effect-modifying structure  376 . For OI structure  180 ,  200 ,  260 , or  270 , the segment of piezoelectric structure  374  in IS segment  192  provides an initial electrical effect along an electrical path  378  to effect-modifying structure  376 , largely the segment of structure  376  in IS segment  192 , in response to pressure, specifically excess SF pressure, of the impact. Structure  376 , likewise largely the structure segment in segment  192 , modifies the initial electrical effect to produce the general impact effect as a modified electrical effect supplied to CC segment  194  along path  372 . 
     For OI structure  300  or  330 , the segment of piezoelectric structure  374  in IS segment  192  provides an initial first electrical effect in response to deformation along SF DF area  122  due to pressure, specifically excess SF pressure, caused by the impact. The segment of structure  374  in segment  192  similarly provides an initial second electrical effect in response to deformation along internal DF area  308  due to pressure, specifically excess internal pressure, exerted by DE structure  302  on area  308  caused by the impact. Both initial electrical effects are supplied along path  378  to effect-modifying structure  376 , largely the structure segment in IS segment  192 . Structure  376 , again largely the structure segment in segment  192 , modifies the initial first and second electrical effects to produce the first and second general impact effects respectively as modified first and second electrical effects supplied to CC segment  194  along path  372 . 
     Effect-modifying structure  376  usually modifies the voltage or/and current of each initial electrical effect to produce the resultant modified electrical effect at modified voltage or/and current suitable for CC component  184 . Structure  376  may amplify, or attenuate, the voltage or/and current of each initial electrical effect as well as shifting its voltage level(s). 
       FIGS. 25 a  and 25 b    depict two embodiments of ISCC structure  132  suitable for OI structure  200 ,  270 ,  300 , or  330 . In  FIG. 25 a   , IS component  182  contains piezoelectric structure  370  arranged and operable the same as in  FIG. 24 a   . CC component  184  in  FIG. 25 a    contains assembly  202  formed with subcomponents  222 ,  224 , and  226 . Auxiliary layers  204  and  206 , neither shown in  FIG. 25 a   , may be present in component  184  of  FIG. 25   a.    
     ISCC structure  132  in  FIG. 25 a    converts the electrical effect on path  372  into principal general CC control signal V nfC  formed by the difference between CC values V nC  and V fC . Although  FIG. 25 a    illustrates this conversion as occurring within CC component  184 , the conversion may occur earlier in the signal processing. Control signal V nfC  is applied between electrode structures  224  and  226  so that near CC value V nC  is present at the VA location in the segment of the electrode layer in NE segment  234 , and far CC value V fC  is present at the VA location in the segment of the electrode layer in FE segment  236 . 
     IS component  182  in  FIG. 25 b    consists of piezoelectric structure  374  and effect-modifying structure  376  arranged and operable the same as in  FIG. 24 b   . CC component  184  in  FIG. 25 b    contains assembly  202  arranged and operable the same as in  FIG. 25 a   . Although  FIG. 25 b    illustrate the conversion of the electrical effect on path  372  into general CC control signal V nfC  as occurring within component  184 , this conversion may occur earlier in the signal processing. In particular, structure  376  in  FIG. 25 b    may perform the conversion. 
     Piezoelectric structure  370  or  374  can be any one or more of numerous piezoelectric materials such as ammonium dihydrogen phosphate NH 4 H 2 PO 4 , potassium dihydrogen phosphate KH 2 PO 4 , monocrystalline or polycrystalline barium titanate BaTiO 3 , lead zirconium titanate PbZr x Ti 1-x O 3 , lead lanthanum zirconium titanate Pb 1-y La y (Zr x Ti 1-x ) 1-0.25y Vac 0.25y O 3  where Vac means vacancy, polyvinylidene fluoride (CH 2 CF 2 ) n , quartz (silicon dioxide) SiO 2 , and zinc oxide. These piezoelectric materials and others are presented in “Piezoelectricity”, Wikipedia, en.wikipedia.org/wiki/Piezoelectricity, 28 Feb. 2013, 11 pp., and the references cited therein, contents incorporated by reference herein. 
     Pictorial Views of Color Changing by Light Reflection and Emission 
       FIGS. 26 a  and 26 b    depict how color changing occurs by light reflection in VC region  106  of OI structure  130  or  340 .  FIGS. 27 a  and 27 b    depict how color changing occurs by light reflection in region  106  of OI structure  180 .  FIGS. 28 a  and 28 b    depict how color changing occurs by light reflection in some embodiments of region  106  of OI structure  200  or  350 .  FIGS. 29 a  and 29 b    depict how color changing occurs by light reflection in region  106  of OI structure  240 .  FIGS. 30 a  and 30 b    depict how color changing occurs by light reflection in region  106  of OI structure  260 .  FIGS. 31 a  and 31 b    depict how color changing occurs by light reflection in some embodiments of region  106  of OI structure  270 . 
     The normal state is presented in  FIGS. 26 a , 27 a , 28 a , 29 a , 30 a , and 31 a    where arrows  380  directed toward VC region  106  from above SF zone  112  represent rays of light striking region  106 . Incident light  380  consists of a mixture of wavelengths across at least one relatively broad part of the visible spectrum. Incident broad-spectrum light  380  typically consists of an appropriate mixture of wavelengths across the entire visible spectrum so as to form light, termed “white light”, further labeled with the letter W. Implementing light  380  with white light provides great flexibility in choosing color A. Nevertheless, light  380  can be significantly non-white light. 
     Arrows  382  directed away from VC region  106  along SF zone  112  in  FIG. 26 a , 27 a , 28 a , 29 a , 30 a   , or  31   a  represent rays of A light leaving region  106 . Region  106  reflects part of light  380  and absorbs or/and transmits, preferably absorbs, the remainder of light  380 . No internally emitted light leaves region  106  via zone  112  in  FIG. 26 a , 27 a , 28 a , 29 a , 30 a   , or  31   a . A light  382  consists nearly entirely of the reflected part of light  380 . 
     A light  382  usually has multiple components as described above but, for simplicity, not indicated in  FIG. 26 a , 27 a , 28 a , 29 a , 30 a   , or  31   a . In  FIG. 26 a   , the light reflection to form most of light  382  can occur along or/and below SF zone  112 . The places where the arrows representing light  382  originate in  FIGS. 27 a , 28 a , 29 a , 30 a , and 31 a    indicate the minimum depths below zone  112  at which light forming most of light  382  is reflected. The light reflection forming most of light  382  in  FIG. 27 a    occurs along or/and below interface  186 . In  FIGS. 28 a  and 31 a   , items  384  in core layer  222  are examples of particles off which part of broad-spectrum light  380  reflects to form most of light  382 . 
     The changed state is presented in  FIGS. 26 b , 27 b , 28 b , 29 b , 30 b , and 31 b   . During the changed state, IDVC portion  138  temporarily reflects part of broad-spectrum light  380  to form reflected light  386  whose rays are represented by arrows leaving portion  138 . Portion  138  absorbs or/and transmits, preferably absorbs, the remainder of light  380  striking it. No internally emitted light leaves portion  138  via print area  118  in  FIG. 26 b , 27 b , 28 b , 29 b , 30 b   , or  31   b . X light thus consists nearly entirely of reflected light  386 . Also, the remainder of VC region  106  continues to reflect A light  382 . 
     Reflected X light  386  usually has multiple components as described above but, for simplicity, not shown in  FIG. 26 b , 27 b , 28 b , 29 b , 30 b   , or  31   b . In  FIG. 26 b   , the light reflection to form most of light  386  can occur along or/and below print area  118 . The places where the arrows representing light  386  originate in  FIGS. 27 b , 28 b , 29 b , 30 b , and 31 b    indicate the minimum depths below area  118  at which light forming most of light  386  is reflected. The light reflection forming most of light  386  in  FIG. 27 b    occurs along or/and below IF segment  196 . 
     Referring to  FIGS. 28 b  and 31 b   , items  388  in ID segment  232  of core layer  222  are examples of selected ones of particles  384 . Selected particles  388  have translated or/and rotated so that part of broad-spectrum light  380  striking particles  388  reflects to form most of light  386 . For exemplary purposes,  FIGS. 28 b  and 31 b    depict particles  388  as being adjacent to NE segment  234  and thus averagely remote from FE segment  236  as arises in the version of the mid-reflection embodiment of CC component  184  where layer  222  contains charged particles of one color distributed in a fluid of another color. Nevertheless, selected particles  388  can translate or/and rotate as described above for any of the other versions of the mid-reflection embodiment of component  184 . 
       FIGS. 32 a  and 32 b    depict how color changing occurs primarily by light emission in VC region  106  of OI structure  130  or  340 .  FIGS. 33 a  and 33 b    depict how color changing occurs primarily by light emission in region  106  of OI structure  180 .  FIGS. 34 a  and 34 b    depict how color changing occurs primarily by light emission in region  106  of OI structure  200  or  350 .  FIGS. 35 a  and 35 b    depict how color changing occurs primarily by light emission in region  106  of OI structure  240 .  FIGS. 36 a  and 36 b    depict how color changing occurs primarily by light emission in region  106  of OI structure  260 .  FIGS. 37 a  and 37 b    depict how color changing occurs primarily by light emission in region  106  of OI structure  270 . 
     The normal state is presented in  FIGS. 32 a , 33 a , 34 a , 35 a , 36 a , and 37 a    where the arrows representing rays of broad-spectrum light  380  are shown in dotted line because change in the reflection of part of light  380  is usually a secondary contributor to color changing. Arrows  392  directed away from VC region  106  along SF zone  112  represent A light leaving region  106 . Region  106  again reflects part of light  380  and absorbs or/and transmits, preferably absorbs, the remainder of light  380 . However, internally emitted light can leave region  106  via zone  112  during the normal state. A light  392  consists of the reflected part of light  380  and any such emitted light. 
     A light  392  usually has multiple components as described above but, for simplicity, not shown in  FIG. 32 a , 33 a , 34 a , 35 a , 36 a   , or  37   a . The locations where the arrows representing light  392  originate in  FIGS. 32 a , 33 a , 34 a , 35 a , 36 a , and 37 a    indicate depths below SF zone  112  at which any emitted part of light  392  can be emitted. Because no significant amount of light emission may occur during the normal state, the arrows representing light  392  are shown in dashed line extending from their potential emission-origination locations upward to the locations of the minimum depths below zone  112  at which reflected light in light  392  is reflected. The arrows representing light  392  in  FIG. 32 a    are shown in dashed line extending from zone  112  to underlying locations because any emitted light in light  392  is usually emitted below zone  112 . In  FIGS. 34 a  and 37 a   , the arrows representing light  392  are shown without dashed-line as originating at the interface between FE structure  226  and FA layer  206  because (i) reflected light in light  392  can be reflected at that interface and (ii) any emitted light in light  392  can be emitted by layer  206 . 
     The changed state is presented in  FIGS. 32 b , 33 b , 34 b , 35 b , 36 b , and 37 b   . Arrows  396  directed away from IDVC portion  138  along print area  118  represent X light leaving portion  138 . X light  396  consists of a reflected part of broad-spectrum light  380  striking portion  138  and usually light emitted by it. Portion  138  absorbs or/and transmits, preferably absorbs, the remainder of light  380  striking it. When X light  396  contains light emitted by portion  138 , the emitted light usually forms most of light  396 . The remainder of VC region  106  continues to reflect A light  392 . 
     X light  396  usually has multiple components as described above, but for simplicity, not indicted in  FIG. 32 b , 33 b , 34 b , 35 b , 36 b   , or  37   b . The locations where the arrows representing light  396  originate in  FIGS. 32 b , 33 b , 34 b , 35 b , 36 b , and 37 b    indicate depths below print area  118  at which the emitted part, if any, of light  396  can be emitted. Because no significant amount of light emission sometimes occurs during the changed state, the arrows representing light  396  are shown in dashed line extending from their potential emission-origination locations upward to the locations of the minimum depths below area  118  at which reflected light in light  396  is reflected. The arrow representing light  396  in  FIG. 32 b    is shown in dashed line extending from area  118  to an underlying location because any emitted light in light  396  is usually emitted below area  118 . In  FIGS. 34 b  and 37 b   , the arrows representing light  396  are shown without dashed line as originating at the interface between FE segment  236  and FA segment  216  because (i) reflected light in light  396  can be reflected at that interface and (ii) any emitted light in light  396  can be emitted by segment  216 . 
     Object-Impact Structure with Cellular Arrangement 
       FIGS. 38 a  and 38 b    (collectively “ FIG. 38 ”) depict the layout of a general embodiment  400  of OI structure  100  in which VC region  106  is allocated into a multiplicity, at least four, usually at least 100, typically thousands to millions, of principal independently operable VC cells  404  arranged laterally in a layer as a two-dimensional array, each VC cell  404  extending to a corresponding part  406  of SF zone  112 . The dotted lines in  FIG. 38  indicate interfaces between SF parts  406  of adjacent cells  404 . The general layout of OI structure  400  is shown in  FIG. 38 a   .  FIG. 38 b    depicts an example of color change that occurs along surface  102  upon being impacted by object  104  indicated in dashed line at a location subsequent to impact. Each cell  404  functions as a pixel cell, its SF part  406  being a pixel. 
     VC cells  404  consist of (a) peripheral cells along the lateral periphery  408  of VC region  106 , each peripheral cell having sides respectively adjoining sides of at least two other peripheral cells, and (b) interior cells spaced apart from lateral periphery  408 , each interior cell having sides respectively adjoining sides of at least four other cells  404 . Cells  404 , usually arrayed in rows and columns across region  106 , are preferably identical but can variously differ. The row and column directions respectively are the horizontal and vertical directions in  FIG. 38 . Peripheral cells  404  may sometimes differ from interior cells  404 . Cell SF parts  406  are usually shaped like polygons, preferably quadrilaterals, more preferably rectangles, typically squares as shown in the example of  FIG. 38 . For rectangles, including squares, each cell column extends perpendicular to each cell row. Other shapes for SF parts  406  are discussed below in regard to  FIGS. 87 a    and  87   b.    
     Cells  404  appear along their parts  406  of SF zone  112  as principal color A during the normal state, A light normally leaving each cell  404  along its SF part  406 . See  FIG. 38 a   . A cell  404  is a principal CM cell if it temporarily appears as changed color X along its part  406  of zone  112  as a result of object  104  impacting OC area  116 , X light temporarily leaving each CM cell  404  along its part  406  of print area  118  during the changed state. See  FIG. 38 b   . Again, “CM” means criteria-meeting. OC area  116  is again capable of being of substantially arbitrary shape. Recitations hereafter of (a) cells  404  normally appearing as color A mean that they normally so appear along their parts  406  of zone  112  and (b) a CM cell  404  temporarily appearing as color X means that it temporarily so appears along its part  406  of area  118 . 
     Each cell  404  that meets principal cellular TH impact criteria in response to object  104  impacting OC area  116  is a principal TH CM cell. The principal cellular TH impact criteria embody the principal basic TH impact criteria. Since the principal basic TH impact criteria can vary with where print area  118  occurs in SF zone  112 , the cellular TH impact criteria can vary with where each cell&#39;s SF part  406  occurs in zone  112 . In some cellular OI embodiments, each TH CM cell  404  temporarily appears as color X during the changed state. In other cellular OI embodiments, other impact criteria must also be met for a TH CM cell  404  to appear as color X during the changed state. Each such TH CM cell  404  then becomes a principal full CM cell, sometimes simply a CM cell. 
     Also, a cell  404  significantly affected by the impact, e.g., by experiencing significant impact-caused excess pressure or/and undergoing significant impact-caused deformation, is a candidate for a CM cell. A candidate cell  404  meeting the cellular TH impact criteria temporarily becomes a TH CM cell and either temporarily appears as color X during the changed state or, if subject to other impact criteria, becomes a full CM cell and temporarily appears as color X if the other impact criteria are met. A cell  404 , including a candidate cell  404 , not meeting the cellular TH impact criteria appears as color A during the changed state. The same applies to a cell  404  for which the other impact criteria are not met in a cellular OI embodiment subject to the other impact criteria. 
     There is invariably an ID group of cells  404  that temporarily constitute CM cells, the ID cell group being a plurality of less than all cells  404 . The ID cell group, termed ID cell group  138 *, embodies IDVC portion  138 . SF parts  406  of CM cells  404  in ID cell group  138 * constitute print area  118  and temporarily appear as color X. CM cells  404  in cell group  138 * are usually cell-wise continuous in that each CM cell  404  adjoins, or is connected  404  via one or more other CM cells  404  to, each other CM cell  404 . 
     The cellular TH impact criteria for each cell  404  can consist of multiple sets of different principal cellular TH impact criteria having the same characteristics as, and employable the same as, the sets of principal basic TH impact criteria. Hence, the sets of different principal cellular TH impact criteria respectively correspond to different specific changed colors (X 1 -X n ). Each cell  404  meeting the cellular TH impact criteria in a cellular OI embodiment not subject to other impact criteria appears as the specific changed color (X i ) for the set of cellular TH impact criteria actually met by the impact. Each cell  404  meeting the cellular TH impact criteria in a cellular OI embodiment subject to other impact criteria appears as the specific changed color (X i ) for the set of cellular TH impact criteria actually met by the impact if the other impact criteria are met. Hence, each cell  404  meeting the cellular TH impact criteria is solely capable of appearing as the specific changed color (X i ) for the set of cellular TH impact criteria actually met by the impact. 
     Print area  118  usually variously extends inside and outside OC area  116  depending on the cellular TH impact criteria. Arranging for areas  116  and  118  to have this type of relationship to each other generally enables the contour of print area  118  to better match the contour of OC area  116  because cell SF parts  406  are of finite size, quadrilaterals here, rather than being points. 
     An indicator ΔR proc  of how close the contour of print area  118  matches the contour of OC area  116  is the sum of the fractional differences in area by which print area  118  extends inside and outside OC area  116 . Let A pri  and A pro  respectively represent the areas by which print area  118  extends inside and outside OC area  116 . Fractional inside-and-outside area difference ΔR proc  is then (A pri +A pro )/A oc  where A oc  is again the area of OC area  116 . Fractional area difference ΔR proc  devolves to A pri /A oc  if print area  118  only extends inside OC area  116  and to A pro /A oc  if print area  118  only extends outside OC area  116 . In percentage, fractional difference ΔR proc  averages usually no more than 10%, preferably no more than 8%, more preferably no more than 6%, even more preferably no more 4%, further preferably no more than 2%, further more preferably no more than 1%. 
     The matching between the contours of areas  116  and  118 , sometimes described as quantized for OI structure  400  because ID cell group  138 * contains an integer number of CM cells  404 , is relatively weak in the example of  FIG. 38 b    where the number of CM cells  404  whose SF parts  406  form quantized print area  118  of cell group  138 * is relatively small. The print-area-to-OC-area matching generally improves as the cell density, or pixel resolution, increases so that more CM cells  404  are present in group  138 * for a given lateral area of group  138 *. “PA” hereafter means print-area. 
     An understanding of how the PA-to-OC-area matching improves with increasing cell density is facilitated with assistance of  FIGS. 39 a  and 39 b    (collectively “ FIG. 39 ”) which depict quantized print area  118  at two different cell densities for an example in which OC area  116  is a true circle. Quantized print area  118  here is a quantized “circle” lying fully within the true circle, subject to certain edges of the quantized circle possibly touching the true circle. Cell SF parts  406  in  FIG. 39  are identical squares, the squares within the quantized circle shown in solid line for clarity. 
     Area A t  of the true circle formed by OC area  116  in  FIG. 39  is πd t   2 /4 where d t  is the diameter of the true circle. Letting d s  represent the dimension of each side of each square, area A q  of the quantized circle is n min d s   2  where n min  is the minimum number of squares fully within the true circle, with certain edges of certain squares possibly touching the true circle, for any location of the true circle on the grid of squares. The ratio R qt  of area A q  of the quantized circle to area A t  of the true circle is 4n min d s   2 /πd t   2 . Letting R cs  represent the ratio of diameter d t  of the true circle to the dimension d s  of each side of each square, circle area ratio R qt  is then 4n min /πR cs   2 . Circle area ratio R qt  approaches 1 as the quantized circle approaches a true circle of diameter d t . 
     The fractional circle area difference ΔR qt  between the contours of the true and quantized circles is 1−R qt . Fractional circle area difference ΔR qt  approaches zero as the quantized circle approaches the true circle and is another indicator of how close the contour of print area  118  matches the contour of OC area  116 . Additionally, the quantized circle often contains more squares than minimum number n min  used in deriving fractional difference ΔR qt . Difference ΔR qt  represents the “worst-case” matching because the difference between the contours of the quantized and true circles is often less than that indicated by difference ΔR qt . 
       FIG. 40  shows how fractional circle area difference ΔR qt  decreases with increasing even-integer values of circle-diameter-to-square-side ratio R cs . Table 2 below presents the data, including minimum number n min  of squares and quantized-circle-to-true-circle area ratio R qt , used in generating  FIG. 40 . Although diameter-to-side ratio R cs  only has even integer values in  FIG. 40  and Table 2, ratio R cs  can have odd integer values as well as non-integer values. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Diameter- 
                 Min. No. 
                   
                   
               
               
                   
                 to-side 
                 n min  of 
                 Area 
                 Diff. ΔR qt   
               
               
                   
                 Ratio R cs   
                 Squares 
                 Ratio R qt   
                 (%) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 4 
                 4 
                 0.318 
                 68.2 
               
               
                   
                 6 
                 16 
                 0.566 
                 43.4 
               
               
                   
                 8 
                 32 
                 0.637 
                 36.3 
               
               
                   
                 10 
                 52 
                 0.662 
                 33.8 
               
               
                   
                 12 
                 88 
                 0.778 
                 22.2 
               
               
                   
                 14 
                 120 
                 0.780 
                 22.0 
               
               
                   
                 16 
                 164 
                 0.816 
                 18.4 
               
               
                   
                 18 
                 216 
                 0.849 
                 15.1 
               
               
                   
                 20 
                 276 
                 0.879 
                 12.1 
               
               
                   
                 22 
                 332 
                 0.873 
                 12.7 
               
               
                   
                 24 
                 392 
                 0.867 
                 13.3 
               
               
                   
                 26 
                 476 
                 0.897 
                 10.3 
               
               
                   
                 28 
                 556 
                 0.903 
                 9.7 
               
               
                   
                 30 
                 652 
                 0.922 
                 7.8 
               
               
                   
                 32 
                 732 
                 0.910 
                 9.0 
               
               
                   
                 34 
                 832 
                 0.916 
                 8.4 
               
               
                   
                 36 
                 952 
                 0.935 
                 6.5 
               
               
                   
                 38 
                 1052 
                 0.927 
                 7.3 
               
               
                   
                 40 
                 1176 
                 0.935 
                 6.5 
               
               
                   
                 42 
                 1288 
                 0.930 
                 7.0 
               
               
                   
                 44 
                 1428 
                 0.939 
                 6.1 
               
               
                   
                 46 
                 1560 
                 0.939 
                 6.1 
               
               
                   
                 48 
                 1696 
                 0.937 
                 6.3 
               
               
                   
                 50 
                 1860 
                 0.947 
                 5.3 
               
               
                   
                   
               
            
           
         
       
     
     Object  104  occupies a maximum area A oc  along SF zone  112  while contacting OC area  116 . Assume that true circle area A t  is approximately OC area A oc . Let N L  represent the lineal density (or resolution), in squares per unit length, of squares needed to achieve a particular value of fractional difference ΔR qt . For a given value of true circle area A t , lineal square density N L  is estimated as (n min /A oc ) 1/2  for any ΔR qt  value in Table 2. For a ΔR qt  value lower than the lowest ΔR qt  value in Table 2, lineal density N L  is estimated using the same formula by extending Table 2 to suitably higher values of minimum square number n min . Because number n min  can become very high, extending Table 2 may entail using a suitable computer program. 
     As an exemplary N L  estimate, OC area A oc  for a tennis ball embodying object  104  is typically 15-20 cm 2 . Assume that a ΔR qt  value of 5-6% is desired. The corresponding n min  value is roughly 1,500-2,000. Using the preceding N L  formula, the desired N L  value is approximately 10 squares/cm or 10 pixels/cm since each square is a pixel. State-of-the art imaging systems easily achieve resolutions of 100 pixels/cm and can usually readily achieve resolutions of 200 pixels/cm. A ΔR qt  value of 5-6% is well within the state of the art. ΔR qt  values considerably less than 5-6% are expected to be readily achievable with OI structure  400 . 
     Different from the model of  FIG. 39  in which the quantized circle embodying print area  118  lies fully within the true circle embodying OC area  116 , print area  118  often extends partly outside OC area  116  as occurs in the example of  FIG. 38 b   . Also, some cell SF parts  406  along the perimeter of OC area  116  may not form part of print area  118 . In the example of  FIG. 38 b   , each cell SF part  406  along the perimeter of OC area  116  forms a portion of print area  118  only when approximately half or more of that SF part&#39;s area is within OC area  116 . Fractional inside-and-outside area difference ΔR proc  for the model of  FIG. 39  equals fractional circle area difference ΔR qt  when the number of squares fully within area  116  is minimum number n min . Circle area difference ΔR qt  can then serve as an estimate of inside-and-outside area difference ΔR proc  for approximately determining the minimum linear cell density needed to achieve a particular ΔR proc  value. Lineal density N L  in cells  404  per unit length is usually at least 10 cells/cm, preferably at least 20 cells/cm, more preferably at least 40 cells/cm, even more preferably at least 80 cells/cm, in both the row and column directions. 
       FIGS. 41 a , 41 b , 42 a , 42 b , 43 a , 43 b , 44 a , 44 b , 45 a , 45 b , 46 a   ,  46   b ,  47   a ,  47   b ,  48   a ,  48   b ,  49   a ,  49   b ,  50   a , and  50   b  present side cross sections of ten embodiments of OI structure  400  where each pair of Figs. ja and jb for integer j varying from 41 to 50 depicts a different embodiment. The basic side cross sections, and thus now the ten embodiments appear in the normal state, are respectively shown in  FIGS. 41 a , 42 a , 43 a , 44 a , 45 a , 46 a , 47 a , 48 a , 49 a , and 50 a    corresponding to  FIG. 38 a   .  FIGS. 41 b , 42 b , 43 b , 44 b , 45 b , 46 b , 47 b , 48 b , 49 b , and 50 b    corresponding to  FIG. 38 b    present examples of changes that occur during the changed state when object  104  contacts surface  102  fully within SF zone  112 . 
     SF DF area  122 , which usually encompasses most of principal OC area  116 , and total OC area  124 , which is identical to OC area  116  in the examples of  FIGS. 41 b , 42 b , 43 b , 44 b , 45 b , 46 b , 47 b , 48 b , 49 b , and 50 b   , are not separately labeled in those figures to simplify the labeling. Nor are areas  122  and  124  separately labeled in earlier  FIG. 38 b   . In the embodiments of  FIGS. 42 a  and 42 b , 43 a  and 43 b , 44 a  and 44 b , 45 a  and 45 b , 46 a  and 46 b , 47 a    and  47   b ,  48   a  and  48   b ,  49   a  and  49   b , and  50   a  and  50   b  where each cell  404  consists of multiple parts, the parts of each cell  404  are not separately labeled to simplify the labeling. 
     As to cell parts described below for subregions  242 ,  182 ,  302 ,  204 ,  224 ,  202 ,  222 , and  226 , each such cell part meets the transmissivity specification given above for corresponding subregion  242 ,  182 ,  302 ,  204 ,  224 ,  202 ,  222 , or  226  containing that cell part. Similarly regarding combinations of functionally different cell parts described below for subregions  242 ,  182 ,  302 ,  204 ,  224 ,  202 ,  222 , and  226 , each such combination of functionally different cell parts meets the transmissivity specification given above for the corresponding combination of subregions  242 ,  182 ,  302 ,  204 ,  224 ,  202 ,  222 , and  226  containing that combination of cell parts. 
     Referring to  FIGS. 41 a  and 41 b   , they illustrate a general embodiment  410  of OI structure  400  for which automatic duration Δt drau  of the changed state is passively determined by the properties of the material in ISCC structure  132 . OI structure  410  is also an embodiment of OI structure  130 . The lateral (side) boundary of each cell  404  usually extends perpendicular to its part  406  of SF zone  112  so as to appear largely as a pair of straight lines along a plane extending through that cell  404  perpendicular to zone  112 . See  FIG. 41 a   . Each cell  404  here consists of a part, termed an ISCC part (or element), of ISCC structure  132 . 
     Each cell  404  here operates the same during the normal state as VC region  106  in OI structure  130 . A light normally leaving each cell  404  via its SF part  406  is formed with ARic light reflected by its ISCC part, any AEic light emitted by its ISCC part, and any substructure-reflected ARsb light passing through its ISCC part. Each cell  404  normally appears as color A. 
     Each cell  404  having its SF part  406  partly or fully in OC area  116  is a candidate for a CM cell. Each CM cell  404  operates the same during the changed state as IDVC portion  138  in structure  130 . Referring to  FIG. 41 b   , X light temporarily leaving each CM cell  404  via its part  406  of print area  118  is formed with XRic light reflected by its ISCC part, any XEic light emitted by its ISCC part, and any substructure-reflected XRsb light passing through its ISCC part. CM cells  404  usually enter the changed state simultaneously and leave the changed state simultaneously. CC duration Δt dr  of each CM cell  404  is largely equal to CC duration Δt dr  of OI structure  400  as a whole. Automatic duration Δt drau  of each CM cell  404  is likewise largely equal to automatic duration Δt drau  of structure  400  as a whole. 
     The ISCC part of each cell  404  here can, subject to the potential modifications described below for  FIG. 51 , be embodied in any of the ways described above for embodying ISCC structure  132  in OI structure  130 . For instance, each cell&#39;s ISCC part can be formed essentially solely with IS CR or CE material. Automatic CC duration Δt drau  for each cell  404  when it is a CM cell is then base portion Δt drbs . 
       FIGS. 42 a  and 42 b    illustrate an embodiment  420  of OI structure  410 . OI structure  420  is also an embodiment of OI structure  180 . ISCC structure  132  of VC region  106  here consists of components  182  and  184  deployed as in OI structure  180  to meet at interface  186 . See  FIG. 42 a   . Each cell  404  here consists of an ISCC part of ISCC structure  132 , the ISCC part formed with (a) a part, termed an IS part, of IS component  182  and (b) a part, termed a CC part, of underlying CC component  184 . The IS part of each cell  404  extends to its SF part  406  and between its boundary portions in IS component  182 . The CC part of each cell  404  extends to substructure  134  and between that cell&#39;s boundary portions in CC component  184 . The cell&#39;s IS and CC parts meet along a corresponding part  424  of interface  186 . 
     The IS and CC parts of each cell  404  respectively operate the same during the normal state as components  182  and  184  in OI structure  180 . Total ATcc light normally leaving the CC part of each cell  404  via its IF part  424  consists of ARcc light reflected by its CC part, any AEcc light emitted by its CC part, and any ARsb light passing through its CC part. A light normally leaving each cell  404  via its SF part  406  consists of ARcc light and any AEcc and ARsb light passing through its IS part and any ARis light reflected by its IS part. 
     Each cell  404  having its SF part  406  partly or fully in OC area  116  is a candidate for a CM cell. Each CM cell  404  operates essentially the same during the changed state as IDVC portion  138  in structure  130 . In particular, each CM cell  404  temporarily appears as color X (a) in some general OI embodiments if it meets the cellular TH impact criteria so as to be a TH CM cell or (b) in other general OI embodiments if it is provided with a principal cellular CC control signal generated in response to it meeting the cellular TH impact criteria sometimes dependent on other impact criteria also being met in those other embodiments so that it becomes a full CM cell. Referring to  FIG. 41 b   , X light temporarily leaving each CM cell  404  via its part  406  of print area  118  is formed with XRic light reflected by its ISCC part, any XEic light emitted by its ISCC part, and any substructure-reflected XRsb light passing through its ISCC part. A light continues to leave each other cell  404  during the changed state. The cellular CC control signals provided to all CM cells  404  implement the general CC control signal. 
     The IS part of each CM cell  404  responds to object  104  impacting OC area  116  so as to meet the cellular TH impact criteria for that CM cell  404  by providing a principal cellular ID impact effect usually resulting from the pressure of the impact on area  116  or from deformation that object  104  causes along SF DF area  122 . The CC part of each CM cell  404  responds (a) in some general OI embodiments to its cellular ID impact effect by causing that CM cell  404  to temporarily appear as color X or (b) in other general OI embodiments to its cellular CC control signal generated in response to its cellular impact effect sometimes dependent on other impact criteria also being met in those other embodiments by causing that CM cell  404  to temporarily appear as color X. Specifically, the CC part of each CM cell  404  changes in such a way that XRcc light reflected by its CC part and any XEcc light emitted by its CC part temporarily leave its CC part. Total XTcc light temporarily leaving the CC part of each CM cell  404  via its IF part  424  consists of XRcc light, any XEcc light, and any XRsb light passing through its CC part. X light temporarily leaving each CM cell  404  via its part  406  of print area  118  consists of XRcc light and any XEcc and XRsb light passing through its IS part and any ARis light reflected by its IS part. A light continues to leave the remainder of cells  404 . The cellular impact effects of all CM cells  404  implement the general impact effect. 
     The IS and CC parts of each cell  404  here can, subject to the potential modifications described below for  FIG. 52 , be respectively embodied in any of the ways described above for embodying components  182  and  184  of OI structure  180 . For instance, the cell&#39;s CC part can be embodied as reduced-size CR or CE CC structure in basically any of the ways that CC component  184  is embodied as a CR or CE CC component. 
       FIGS. 43 a  and 43 b    illustrate an embodiment  430  of OI structure  420 . OI structure  430  is also an embodiment of OI structure  200  and thus of OI structure  180 . CC component  184  is formed with assembly  202  and optional auxiliary layers  204  and  206 . See  FIG. 43 a   . The CC part of each cell  404  consists of (a) a part, termed an (electrode) AB part, of assembly  202 , (b) a part, termed an NA part, of NA layer  204 , and (c) a part, termed an FA part, of FA layer  206 . The AB, NA, and FA parts of each cell  404  each extend between the cell&#39;s lateral boundary portions in component  184 . The NA part of each cell  404  extends to its part  424  of interface  186 . The FA part of each cell  404  extends to its part of interface  136 . The AB part of each cell  404  extends between its NA and FA parts. 
     The AB, NA, and FA parts of each cell  404  respectively operate the same during the normal state as assembly  202  and auxiliary layers  204  and  206  in OI structure  200 . The cell&#39;s FA part specifically operates during the normal state according to a light non-outputting normal cellular far auxiliary mode or one of several versions of a light outputting normal cellular far auxiliary mode. “CFA” hereafter means cellular far auxiliary. Largely no light leaves the FA part of each cell  404  along its AB part in the light non-outputting normal CFA mode. The light outputting normal CFA mode consists of one or both of the following actions: (a) a substantial part of any ARsb light leaving substructure  134  along the FA part of each cell  404  passes through its FA part and (b) ADfa light formed with any ARfa light reflected by its FA part and any AEfa light emitted by its FA part leaves its FA part along its AB part. Total ATfa light normally leaving the FA part of each cell  404  along its AB part consists of any such ARfa, AEfa, and ARsb light. 
     The AB part of each cell  404  operates during the normal state according to a light non-outputting normal cellular assembly mode or one of a group of versions of a light outputting normal cellular assembly mode. “CAB” hereafter means cellular assembly. Largely no light leaves the AB part of each cell  404  along its NA part in the light non-outputting normal CAB mode. The light outputting normal CAB mode consists of one or more of the following actions: (a) a substantial part of any ARsb light passing through the FA part of each cell  404  passes through its AB part, (b) substantial parts of any ARfa and AEfa light provided by its FA part pass through its AB part, and (c) ADab light formed with any ARab light reflected by its AB part and any AEab light emitted by its AB part leaves its AB part along its NA part. Total ATab light normally leaving the AB part of each cell  404  along its NA part consists of any such ARab, AEab, ARfa, AEfa, and ARsb light. 
     Each cell&#39;s NA part operates as follows during the normal state. Substantial parts of any ARab, AEab, ARfa, AEfa, and ARsb light leaving the AB part of each cell  404  pass through its NA part. In addition, the NA part of each cell  404  may normally reflect ARna light. Total ATcc light normally leaving the NA part of each cell  404 , and thus its CC part, via its IF part  424  consists of any such ARab, AEab, ARfa, AEfa, ARna, and ARsb light. 
     The IS part of each cell  404  operates the same during the normal state as IS component  182  of OI structure  420  where ARcc light in structure  420  consists of any ARab, ARfa, ARna, and ARsb light and where AEcc light in structure  420  consists of any AEab and AEfa light. Substantial parts of any ARab, AEab, ARfa, AEfa, ARna, and ARsb light leaving the NA part of each cell  404  pass through its IS part. Including any ARis light normally reflected by the IS part of each cell  404 , any ARab, AEab, ARfa, AEfa, ARis, ARna, and ARsb light normally leaving its IS part, and thus that cell  404  itself, via its SF part  406  form A light. 
     Upon going to the changed state, the AB, NA, and FA parts of each CM cell  404  respectively respond to the cellular impact effect provided by its IS part the same as AB segment  212  and auxiliary segments  214  and  216  in IDVC portion  138  of OI structure  200  respond to the general impact effect. See  FIG. 43 b   . More particularly, the FA part of each CM cell  404  temporarily operates, usually passively, according to a light non-outputting changed CFA mode or one of several versions of a light outputting changed CFA mode. Largely no light leaves the FA part of each CM cell  404  along its AB part in the light non-outputting changed CFA mode. The light outputting changed CFA mode consists of one or both of the following actions: (a) a substantial part of any XRsb light leaving substructure  134  along the FA part of each CM cell  404  passes through its FA part and (b) XDfa light formed with any XRfa light reflected by its FA part and any XEfa light emitted by its FA part leaves its FA part along its AB part. Reflection of XRfa light or/and emission of XEfa light leaving the FA part of each CM cell  404  usually occur under control of its AB part operating in response (a) in first cellular OI embodiments to its cellular impact effect for the impact meeting its cellular TH impact criteria or (b) in second cellular OI embodiments to its cellular CC control signal generated in response to its cellular impact effect sometimes (conditionally) dependent on other impact criteria also being met in the second embodiments. If FA layer  206  normally reflects ARfa light or/and emits AEfa light, a change in which largely no light temporarily leaves the FA part of each CM cell  404  likewise usually occurs under control of its AB part responding to its cellular impact effect or its cellular control signal. Total XTfa light leaving the FA part of each CM cell  404  along its AB part consists of any such XRfa, XEfa, and XRsb light. 
     The AB part of each CM cell  404  responds (a) in the first cellular OI embodiments to its cellular impact effect or (b) in the second cellular OI embodiments to its cellular CC control signal generated in response to the effect sometimes dependent on both its cellular TH impact criteria and other criteria being met by temporarily operating according to a light non-outputting changed CAB mode or one of a group of versions of a light outputting changed CAB mode. Largely no light leaves the AB part of each CM cell  404  along its NA part in the light non-outputting changed CAB mode. The light outputting changed CAB mode consists of one or more of the following actions: (a) a substantial part of any XRsb light passing through the FA part of each CM cell  404  passes through its AB part, (b) substantial parts of any XRfa and XEfa light provided by its FA part pass through its AB part, and (c) XDab light formed with any XRab light reflected by its AB part and any XEab light emitted by its AB part leaves its AB part along its NA part. Total XTab light leaving the AB part of each CM cell  404  along its NA part consists of any such XRab, XEab, XRfa, XEfa, and XRsb light. 
     The NA part of each CM cell  404  operates as follows during the changed state. Substantial parts of any XRab, XEab, XRfa, XEfa, and XRsb light leaving the AB part of each CM cell  404  pass through its NA part. If NA layer  204  reflects ARna light during the normal state, the NA part of each CM cell  404  reflects XRna light, usually largely ARna light, during the changed state. If the NA part of each CM cell  404  undergoes a change so that XRna light significantly differs from ARna light, the change usually occurs under control of the AB part of that CM cell  404  in responding to its cellular impact effect or to its cellular control signal. Total XTcc light leaving the NA part of each CM cell  404 , and thus its CC part, along its IF part  424  consists of any such XRab, XEab, XRfa, XEfa, XRna, and XRsb light. 
     The IS part of each CM cell  404  operates the same during the changed state as IS segment  192  of OI structure  420  where XRcc light consists of any XRab, XRfa, XRna, and XRsb light and where XEcc light consists of any XEab and XEfa light. Substantial parts of any XRab, XEab, XRfa, XEfa, XRna, and XRsb light leaving the AB part of each CM cell  404  pass through its IS part. Including any ARis light reflected by the IS part of each CM cell  404 , any XRab, XEab, XRfa, XEfa, ARis, XRna, and XRsb light leaving its IS part, and thus that CM cell  404  itself, via its part  406  of print area  118  form X light. 
     Analogous to what occurs with the normal and changed GAB modes, either of the changed CAB modes, including any of the versions of the light outputting changed CAB mode, can generally be combined with either of the normal CAB modes, including any of the versions of the light outputting normal CAB mode, in an embodiment of CC component  184  except for combining the light non-outputting changed CAB mode with the light non-outputting normal CAB mode provided, however, that the operation of the changed CAB mode is compatible with the operation of the normal CAB mode. As with the GFA modes, this compatibility requirement may effectively preclude combining certain versions of the light outputting changed CAB mode with certain versions of the light outputting normal CAB mode. 
     Assembly  202  here consists of core layer  222  and electrode structures  224  and  226 . Each cell&#39;s AB part is formed with (a) a part, termed a core part, of layer  222 , (b) a part, termed an NE part, of NE structure  224 , and (c) a part, termed an FE part, of FE structure  226 . The core part of each cell  404  extends between its NE and FE parts which respectively meet its NA and FA parts. The core, NE, and FE parts of each cell  404  also each extend between its lateral boundary portions in assembly  202 . 
     Each cell&#39;s NE part contains a near electrode of the electrode layer in NE structure  224 . Each cell&#39;s FE part similarly contains a far electrode of the electrode layer in FE structure  226 . The electrodes in each cell  404  are at least partly located opposite each other. At least part, termed the core section, of the core part of each cell  404  is located at least partly between its electrodes.  FIG. 53 , dealt with below, presents an example of this configuration for the core section and electrodes of each cell  404 . 
     The core, NE, and FE parts of each cell  404  respectively operate the same during the normal state as core layer  222 , NE structure  224 , and FE structure  226  in OI structure  200 . Controllable voltage V n  on each cell&#39;s near electrode is normally at near normal control value V nN . Controllable voltage V f  on each cell&#39;s far electrode is normally at far normal control value V fN . Control voltage V nf  applied by the electrodes in each cell  404  across its core section is normally at normal control value V nfN  equal to V nN −V fN . Value V nfN  is chosen such that each cell  404  normally appears as color A. 
     With the foregoing in mind, each cell&#39;s FE part undergoes the following normal-state light processing. Largely no light leaves the FE part of each cell  404  along its core part if its AB part is in the light non-outputting normal CAB mode. One or more of the following actions occur with the FE part of each cell  404  if its AB part is in the light outputting normal CAB mode: (a) a substantial part of any ARsb light passing through its FA part passes through its FE part, (b) substantial parts of any ARfa and AEfa light provided by its FA part pass through its FE part, and (c) its FE part reflects ARfe light leaving its FE part along its core part. Total ATfe light normally leaving the FE part of each cell  404  along its core part consists of any such ARfa, AEfa, ARfe, and ARsb light. 
     Each cell&#39;s core part undergoes the following normal-state light processing. Largely no light leaves the core part of each cell  404  along its NE part if its AB part is in the light non-outputting normal CAB mode. One or more of the following actions occur in the core part of each cell  404  if its AB part is in the light outputting normal CAB mode so as to implement that mode for its core part: (a) a substantial part of any ARsb light passing through its FE part passes through its core part, (b) substantial parts of any ARfa and AEfa light passing through its FE part pass through its core part, (c) a substantial part of any ARfe light reflected by its FE part passes through its core part, and (d) ADcl light formed with any ARcl light reflected by its core part and any AEcl light emitted by its core part leaves its core part along its NE part. Total ATcl light normally leaving the core part of each cell  404  along its NE part consists of any such ARcl, AEcl, ARfa, AEfa, ARfe, and ARsb light. 
     Each cell&#39;s NE part undergoes the following normal-state light processing. Substantial parts of any ARcl, AEcl, ARfa, AEfa, ARfe, and ARsb light leaving the core part of each cell  404  pass through its NE part. In addition, the NE part of each cell  404  may normally reflect ARne light. Total ATab light normally leaving the NE part, and thus the AB part, of each cell  404  along its NA part consists of any such ARcl, AEcl, ARfa, AEfa, ARne, ARfe, and ARsb light. Total ATcc light of each cell  404  consists of any ARcl, AEcl, ARfa, AEfa, ARna, ARne, ARfe, and ARsb light leaving that cell  404  along its IF part  424 . Any ARcl, AEcl, ARfa, AEfa, ARis, ARna, ARne, ARfe, and ARsb light normally leaving each cell  404  via its SF part  406  form A light. 
     In going into the changed state, control voltage V nf  applied by the two electrodes in each CM cell  404  across its core section goes to changed control value V nfC  equal to V nC −V fC  in response (a) in the first cellular OI embodiments to its cellular impact effect provided by its IS part for the impact meeting its cellular TH impact criteria or (b) in the second cellular OI embodiments to its cellular CC control signal generated in response to the effect sometimes dependent on other impact criteria also being met in the second embodiments. Voltage V n  on the near electrode in each CM cell  404  is at near CC value V nC . Voltage V f  on the far electrode in each CM cell  404  is at far CC value V fC . As mentioned above, CC values V nC  and V fC  are chosen such that changed value V nfC  differs materially from normal value V nfN . The V nf  change across the core section in each CM cell  404  causes total light XTcl leaving its core part during the changed state to differ materially from total light ATcl leaving its core part during the normal state. Total XTab light of each CM cell  404  differs materially from its total ATab light. This enables each CM cell  404  to temporarily appear as color X. 
     The FE part of each CM cell  404  undergoes the following changed-state light processing. Largely no light leaves the FE part of each CM cell  404  if its AB part is in the light non-outputting changed CAB mode. One or more of the following actions occur with the FE part of each CM cell  404  if its AB part is in the light outputting changed CAB mode: (a) a substantial part of any XRsb light passing through its FA part passes through its FE part, (b) substantial parts of any XRfa and XEfa light provided by its FA part pass through its FE part, and (c) its FE part reflects XRfe light leaving its FR part along its core part. Total XTfe light leaving the FE part of each CM cell  404  along its core part consists of any such XRfa, XEfa, XRfe, and XRsb light. 
     The core part of each CM cell  404  responds (a) in the first cellular OI embodiments to its cellular impact effect or (b) in the second cellular OI embodiments to its cellular CC control signal generated in response to the effect sometimes dependent on both its cellular TH impact criteria and other criteria being met by undergoing the following changed-state light processing. Largely no light leaves the core part of each CM cell  404  along its NE part if its AB part is in the light non-outputting changed CAB mode. One or more of the following actions occur in the core part of each CM cell  404  if its AB part is in the light outputting changed CAB mode so as to implement that mode for its core part: (a) a substantial part of any XRsb light passing through its FE part passes through its core part, (b) substantial parts of any XRfa and XEfa light passing through its FE part pass through its core part, (c) a substantial part of any XRfe light reflected by its FE part passes through its core part, and (d) XDcl light formed with XRcl light reflected by its core part and any XEcl light emitted by its core part leaves its core part along its NE part. Total XTcl light of each CM cell  404  consists of any such XRcl, XEcl, XRfa, XEfa, XRfe, and XRsb light. 
     The NE part of each CM cell  404  undergoes the following changed-state light processing. Substantial parts of any XRcl, XEcl, XRfa, XEfa, XRfe, and XRsb light leaving the core part of each CM cell  404  pass through its NE part. If the NE part of each cell  404  reflects ARne light during the normal state, the NE part of each CM cell  404  reflects XRne light, usually largely ARne light, during the changed state. Total XTab light leaving the NE part, and thus the AB part, of each CM cell  404  along its NA part consists of any such XRcl, XEcl, XRfa, XEfa, XRne, XRfe, and XRsb light. Total XTcc light of each CM cell  404  consists of any XRcl, XEcl, XRfa, XEfa, XRna, XRne, XRfe, and XRsb light leaving that CM cell  404  via its IF part  424 . Any XRcl, XEcl, XRfa, XEfa, ARis, XRna, XRne, XRfe, and XRsb light leaving the IS part of each CM cell  404 , and thus that CM cell  404  itself, via its part  406  of print area  118  form X light. 
     The AB, NA, and FA parts of each cell  404  can, subject to the potential modifications described below for  FIG. 53 , be embodied in any of the ways described above for respectively embodying assembly  202  and auxiliary layers  204  and  206  in OI structure  200 . Also subject to those potential modifications, the core, NE, and FE parts of each cell&#39;s AB part can be embodied in any of the ways described above for respectively embodying core layer  222  and electrode structures  224  and  226  in OI structure  200 . 
     The NA part of each cell  404  can include a programmable RA part (not separately shown), typically separated from that cell&#39;s AB part by insulating material, for being electrically programmed subsequent to manufacture of OI structure  430  for adjusting colors A and X for that cell  404 . The RA cell parts are preferably clear transparent prior to programming. The programming causes the RA part to become tinted transparent or more tinted transparent if it was originally tinted transparent. ARna and Xna light are thereby adjusted for each cell  404 . As a result, colors A and X for each cell  404  are respectively adjusted from pre-programming colors A i  and X i  to post-programming colors A f  and X f . 
     The programming of the RA cell parts can be done by various techniques. In one technique, a blanket conductive programming layer is temporarily deployed on SF zone  112  prior to programming. A programming voltage is applied between the programming layer and the NE part of each cell  404  sufficiently long to cause its RA part to change to a desired tinted transparency. The programming layer is usually removed from zone  112 . In another technique, each cell  404  includes a permanent conductive programming part, typically constituted with part of the NA part of that cell  404 , lying between its SF part  406  and its RA part. A programming voltage is applied between the programming part of each cell  404  and its NE part sufficiently long to cause its RA part to change to a desired tinted transparency. The tinted adjustment can be caused by introduction of RA ions into the RA parts. 
     Alternatively, the core part of each cell  404  can include a programmable RA part lying along that cell&#39;s NE part and having the foregoing transparency characteristics. The core RA part of each cell  404  is programmed to a desired tinted transparency by applying a programming voltage between its NE and FE parts for a suitable time period. Introduction of RA ions into each cell&#39;s core RA part can cause the tinting adjustment. The magnitude of the programming voltage is usually much greater than the V nfN  and V nfC  magnitudes. Regardless of whether the RA part of each cell  404  is located in its NA or NE part, the programming voltage can be a selected one of plural different programming values for causing final color A f  or X f  to be a corresponding one of like plural different specific final principal or changed colors. 
     The RA part of each cell  404  can include three or more transparent RA subparts, each programmable to reflect light of a different one of three or more primary colors, e.g., red, green, and blue, combinable to produce many colors usually including white. The NE part of each cell  404  then includes three or more NE subparts respectively adjacent the RA subparts. One or more, up to all, of the RA subparts of each cell  404  are programmed to cause each programmed RA subpart to change to a desired tinted transparency of that subpart&#39;s primary color. Color A can thus be adjusted across a broad realm of specific colors during the normal state. The same applies to color X for each CM cell  404  during the changed state. Programming is the same as described above except that, depending on which of the preceding cell arrangements is used, a programming voltage is applied between the NE subpart of each programmed RA subpart and its FE part, its programming part, or the programming layer. Adjusting the programming voltage, value or/and duration, for each programmed RA subpart usually enables its final tinted transparency to be programmably adjusted. 
     When LE elements fixedly located in the core parts are used in color changing, the core part of each cell  404  has a core-part emissive area across which AEcl light is emitted during the normal state in the mid-emission EN and EN-ET embodiments and XEcl light is emitted during the changed state in the mid-emission ET and EN-ET embodiments if that cell  404  is a CM cell. The core part of each cell  404  can include three or more core subparts, each containing one or more LE elements operable to emit light of a different one of three or more primary colors, e.g., again red, green, and blue, combinable to produce many colors usually including white. The core subpart of each cell  404  usually emits that subpart&#39;s primary color across a core-part emissive subarea of that core part&#39;s emissive area. The standard human eye/brain would interpret the combination of the primary colors of the light emitted by the core subparts in each cell  404  as color AEcl during the normal state in the mid-emission EN and EN-ET embodiments if the AEcl light traveled to the human eye unaccompanied by other light. The same applies to color XEcl and XEcl light for each CM cell  404  during the changed state in the mid-emission ET and EN-ET embodiments. 
     Each core subpart can be configured to receive a voltage causing the radiosity of the primary-color light emitted from that subpart&#39;s emissive subarea to be fixedly adjusted. The radiosities of the light of the primary colors emitted from each core-part emissive area can then be programmably adjusted subsequent to manufacture of OI structure  430  for enabling AEcl light, and thus A light, in the mid-emission EN and EN-ET embodiments to be fixedly adjusted and for enabling XEcl light, and thus X light, in the mid-emission ET and EN-ET embodiments to be fixedly adjusted. The programming is performed, as necessary, for each primary color, by providing the core subparts operable to emit light of that primary color with a programming voltage that causes them to emit light of their primary color at radiosity suitable for the desired AEcl light in the mid-emission EN and EN-ET embodiments and suitable for the desired XEcl light in the mid-emission ET and EN-ET embodiments. Programming of the RA cell parts and core-part emissive areas can be used in the mid-emission embodiments to expand the realms of specific colors that embody colors A and X. 
       FIGS. 44 a  and 44 b    illustrate an extension  440  of OI structure  410 . OI structure  440  is also an embodiment of OI structure  240 . VC region  106  here consists of SF structure  242  and underlying ISCC structure  132  which meet along interface  244 . See  FIG. 44 a   . SF structure  242  again performs various functions usually including protecting ISCC structure  132  from damage and/or spreading pressure to improve the matching between print area  118  and OC area  116  during impact. Structure  242  here likewise may provide velocity restitution matching or/and strongly influence principal color A or/and changed color X. Each cell  404  here consists of (a) a part, termed the SS part, of structure  242  and (b) the underlying ISCC part of ISCC structure  132 . The SS and ISCC parts of each cell  404  meet along a part  444  of interface  244 . 
     Each cell&#39;s ISCC part here operates the same during the normal state as in OI structure  410  except that light leaving the ISCC part of each cell  404  via its SF part  406  in structure  410  leaves its ISCC part via its part  444  of interface  244  here. Total ATic light normally leaving the ISCC part of each cell  404  via its IF part  444  consists of ARic light reflected by its ISCC part, any AEic light emitted by its ISCC part, and any ARsb light passing through its ISCC part. Including any ARss light normally reflected by the SS part of each cell  404 , A light is formed with ARic light and any AEic, ARss, and ARsb light normally leaving its SS part, and thus that cell  404 , via its SF part  406 . 
     Referring to  FIG. 44 b   , the impact of object  104  on OC area  116  creates excess SF pressure along area  116 . The excess SF pressure is transmitted through SF structure  242  to interface  244  producing excess internal pressure along DP IF area  256 . Each cell  404  having its IF part  444  partly or fully located in area  256  is a candidate for a CM cell. A candidate cell  404  temporarily becomes a CM cell if the excess internal pressure along its IF part  444  meets principal cellular excess internal pressure criteria which embody the cellular TH impact criteria. The cellular excess internal pressure criteria require that the excess internal pressure at one or more points along IF part  444  of a cell  404  equal or exceed a local TH value for that cell  404  to temporarily be a CM cell. 
     During the changed state, the ISCC part of each CM cell  404  responds (a) in some cellular OI embodiments to the excess internal pressure along its IF part  444  meeting its cellular excess internal pressure criteria or (b) in other OI embodiments to its cellular CC control signal generated in response to the excess internal pressure along its IF part  444  meeting its cellular excess internal pressure criteria sometimes dependent on other impact criteria also being met in those other embodiments by changing in such a way that XRic light reflected by the ISCC part of that CM cell  404  and any XEic light emitted by its ISCC part temporarily leave that part via its IF part  444 . Total XTic light leaving the ISCC part of each CM cell  404  via its IF part  444  consists of XRic light, any XEic light, and any XRsb light passing through its ISCC part. Including any ARss light reflected by the SS part of each CM cell  404 , X light is formed with XRic light and any XEic, ARss, and XRsb light leaving its SS part, and thus that CM cell  404 , via its part  406  of print area  118 . 
     For the protective function, the SS part of each cell  404  protects its ISCC part from damage in the above-described way that SF structure  242  in OI structure  240  protects ISCC structure  132  from damage. 
     For pressure spreading, SF structure  242  is again a PS structure, “PS” again meaning pressure-spreading. The SS and ISCC parts of each cell  404  respectively are PS and PSCC parts which adjoin each other along its part  444  of interface  244  again serving as an internal PS surface, “PSCC” again meaning pressure-sensitive color-change. The PSCC part of each cell  404  causes it to temporarily appear as color X if excess internal pressure along its IF part  444  meets the principal cellular excess internal pressure criteria. 
     As to the benefits of pressure spreading, consider what happens in OI structure  410  lacking SF structure  242 . Referring to  FIG. 41 b    corresponding to  FIG. 44 b   , each cell  404  having its SF part  406  located partly or fully in OC area  116  in OI structure  410  is, as mentioned above, a candidate for a CM cell. Certain of those candidate cells  404  in structure  410  become CM cells which temporarily appear as color X. Returning to  FIG. 44 b   , more cells  404  here are candidates for CM cells than in structure  410  because DP IF area  256  extends laterally beyond oppositely situated area  116 . Depending on the cellular excess internal pressure criteria, more cells  404  can be CM cells here than in structure  410 . Importantly, appropriate choice of the cellular excess internal pressure criteria enables print area  118  to closely match OC area  116 . 
       FIGS. 45 a  and 45 b    illustrate an embodiment  450  of OI structure  440 . OI structure  450  is also an extension of OI structure  420  and an embodiment of OI structure  260 . VC region  106  here consists of SF structure  242  and underlying ISCC structure  132  formed with components  182  and  184 . See  FIG. 45 a   . SF structure  242  here is configured and operable the same as in OI structure  440 . Each cell  404  consists of an SS part of structure  242  and the underlying ISCC part of ISCC structure  132 , the ISCC part being formed with an IS part of IS component  182  and a CC part of CC component  184  deployed as in OI structure  420 . 
     Each cell&#39;s IS and CC parts here are configured and operable the same as in OI structure  420 . Total ATic light normally leaving the IS part, and thus the ISCC part, of each cell  404  via its IF part  444  consists of ARcc light and any AEcc, ARis, and ARsb light. ARcc light and any AEcc, ARss, ARis, and ARsb light normally leave each cell  404  via its part  406  of SF zone  112  to form A light. 
     Referring to  FIG. 45 b   , the IS part of each CM cell  404  provides a principal cellular impact effect in response to object  104  impacting the SS part of that CM cell  404  along its surface part  406  so as to meet its cellular TH impact criteria. The cellular impact signal of each CM cell  404  is specifically provided during the changed state in response to the excess internal pressure along IF part  444  of that CM cell  404  meeting the above-mentioned cellular excess internal pressure criteria which embody the cellular TH impact criteria. The CC part of each CM cell  404  responds (a) in some cellular OI embodiments to its cellular impact effect or (b) in other cellular OI embodiments to its cellular CC control signal generated in response to its impact effect sometimes dependent on other impact criteria also being met in those other embodiments by changing in such a way that total XTic light leaving its IS part, and thus its ISCC part, via its IF part  444  consists of XRcc light and any XEcc, ARis, and XRsb light. XRcc light and any XEcc, ARss, ARis, and XRsb light leave each CM cell  404  via its part  406  of area  118  to form X light. 
       FIGS. 46 a  and 46 b    illustrate an embodiment  460  of OI structure  450 . OI structure  460  is also an extension of OI structure  430  and an embodiment of OI structure  270 . VC region  106  here consists of SF structure  242  and ISCC structure  132  formed with IS component  182  and underlying CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206  deployed as in OI structure  430 . See  FIG. 46 a   . SF structure  242  here is configured and operable the same as in OI structure  450  and thus the same as in OI structure  440 . Each cell  404  consists of an SS part of SF structure  242  and the underlying ISCC part of ISCC structure  132 , the ISCC part being formed with an IS part of IS component  182  and the underlying CC part of CC component  184 . Each cell&#39;s CC part consists of an NA part of NA layer  204 , an NE part of NE structure  224 , a core part of core layer  222 , an FE part of FE structure  226 , and an FA part of FA layer  206  deployed as in OI structure  430 . 
     The IS, NA, NE, core, FE, and NA parts of each cell  404  are configured and operable the same as in OI structure  430 . Total ATab light of each cell  404  consists of any ARcl, AEcl, ARfa, AEfa, ARne, ARfe, and ARsb light normally leaving that cell  404  along its NA part. Any ARcl, AEcl, ARfa, AEfa, ARss, ARis, ARna, ARne, ARfe, and ARsb light normally leave each cell  404  via its part  406  of SF zone  112  to form A light. 
     Referring to  FIG. 46 b   , the IS part of each CM cell  404  again provides a principal cellular impact effect in response to object  104  impacting the SS part of that CM cell  404  along its SF part  406  so as to meet its cellular TH impact criteria. The cellular impact signal of each CM cell  404  is specifically provided during the changed state in response to the excess internal pressure along IF part  444  of that CM cell  404  meeting the cellular excess internal pressure criteria which embody the cellular TH impact criteria. The AB part of each CM cell  404  responds (a) in some cellular OI embodiments to its cellular impact effect or (b) in other cellular OI embodiments to its cellular CC control signal generated in response to its impact effect sometimes dependent on both its cellular TH impact criteria and other criteria being met by changing so that its total XTab light consists of any XRcl, XEcl, XRfa, XEfa, XRne, XRfe, and XRsb light leaving that CM cell  404  along its NA part. Any XRcl, XEcl, XRfa, XEfa, ARss, ARis, XRna, XRne, XRfe, and XRsb light leave each CM cell  404  along its part  406  of SF zone  112  to form X light. 
     The cellular impact effects can be transmitted outside VC region  106 . For instance, the cellular impact effects can respectively take the form of multiple cellular location-identifying impact signals supplied to a separate cell CC duration controller as described below for  FIGS. 59 a  and 59 b    or multiple characteristics-identifying impact signals supplied to a separate intelligent cell CC controller as described below for  FIGS. 69 a    and  69   b.    
       FIGS. 47 a  and 47 b    illustrate an extension  470  of OI structure  410  provided with CC duration extended in a pre-established deformation-controlled manner. OI structure  470  is also an embodiment of OI structure  280 . VC region  106  here consists of ISCC structure  132  and underlying DE structure  282 . See  FIG. 47 a   . Each cell  404  consists of (a) an ISCC part of ISCC structure  132  and (b) a part, termed a DE part, of DE structure  282 . The ISCC and DE parts of each cell  404  meet along a part  474  of interface  284 . 
     Each cell  404  here operates the same during the normal state as VC region  106  in OI structure  280 . A light normally leaving each cell  404  via its SF part  406  is formed with ARic light reflected by its ISCC part, any AEic light emitted by its ISCC part, any ARde passing through its ISCC part, and any ARsb light passing through its ISCC and DE parts. 
     The ISCC part of each cell  404  having its SF part  406  partly or fully in SF DF area  122  responds to object  104  impacting its SF part  406  by deforming along a cellular SF DF area constituted partly or fully with its SF part  406  so as to become a candidate for a CM cell. See  FIG. 47 b   . A candidate cell  404  temporarily becomes a CM cell if the impact on that cell&#39;s SF DF area meets the cellular TH impact criteria, i.e., if that cell&#39;s SF deformation meets principal cellular SF DF criteria embodying the cellular TH impact criteria. The deformation along the SF DF area of each CM cell  404  then causes it to temporarily appear as color X for base duration Δt drbs  during the changed state. 
     The DE part of each candidate cell  404  responds to the deformation along its SF DF area, and thus to object  104  impacting its SF part  406 , by deforming along a cellular internal DF area constituted partly or fully with its part  474  of interface  284 . Since interface  284  is a surface of ISCC structure  132 , the deformation of the DE part of each candidate cell  404  along its internal DF area causes its ISCC part to deform. If a candidate cell  404  is a CM cell, the internal deformation of its ISCC part along its internal DF area causes that CM cell  404  to further temporarily appear as color X for extension duration Δt drext . Automatic duration Δt drau  for that CM cell  404  lengthens from Δt drbs  to Δt drbs +Δt drext . 
     Each CM cell  404  here undergoes the same changed-state light processing as in IDVC portion  138  of OI structure  280 . X light leaving each CM cell  404  via its part  406  of print area  118  is formed with XRic light reflected by its ISCC part, any XEic light emitted by its ISCC part, any XRde passing through its ISCC part, and any XRsb light passing through its ISCC and DE parts. 
       FIGS. 48 a  and 48 b    illustrate an extension  480  of OI structure  430  provided with CC duration extended in a pre-established deformation-controlled manner. OI structure  480  is also an embodiment of OI structure  300 . VC region  106  here contains DE structure  302  lying between overlying IS component  182  and underlying CC component  184  to respectively meet them along interfaces  304  and  306 . See  FIG. 48 a   . Each cell  404  consists of (a) an ISCC part of ISCC structure  132  and (b) a part, termed a DE part, of DE structure  302 , the ISCC part being formed with (a) an IS part of IS component  182  located above the DE part and (b) a CC part of CC component  184  located below the DE part. Each cell&#39;s IS and DE parts meet along a part  484  of interface  304 . Each cell&#39;s DE and CC parts meet along a part  486  of interface  306 . Each cell&#39;s CC part is formed with an NA part of NA layer  204 , an NE part of NE structure  224 , a core part of core layer  222 , an FE part of FE structure  226 , and an FA part of FA layer  206  deployed as in OI structure  430 . 
     Each cell  404  here operates the same during the normal state as VC region  106  of OI structure  300 . Total ATcc light of each cell  404  consists of ARcc light reflected by its CC part, any AEcc light emitted by its CC part, and any ARsb light passing through its CC part. A light normally leaving each cell  404  via its SF part  406  is formed with ARcc light passing through its IS and DE parts, any AEcc and ARsb light passing through its IS and DE parts, any ARde light passing through its IS part, and any ARis light reflected by its IS part. Each cell&#39;s NA, NE, core, FE, and FA parts here operate the same during the normal state as in OI structure  430 . 
     The IS part of each cell  404  having its SF part  406  partly or fully in SF DF area  122  responds to object  104  impacting its SF part  406  by deforming along a cellular SF DF area constituted partly or fully with its SF part  406 . See  FIG. 48 b   . That cell  404  temporarily becomes a CM cell if the cellular TH impact criteria are met, i.e., if the SF deformation meets principal cellular SF DF criteria embodying the cellular TH impact criteria so that the changed state begins. The IS part of each CM cell  404  then provides a cellular impact effect, termed the principal cellular first impact effect. The principal cellular first impact effects provided by the IS parts of all CM cells  404  form the principal general first impact effect provided by IS component  182  of OI structure  300  in response to the impact. 
     The CC part of each CM cell  404  here responds to the cellular first impact effect provided from its IS part by changing the same as CC segment  194  in OI structure  300  changes in response to the general first impact effect. Total XTcc light of each CM cell  404  consists of XRcc light reflected by its CC part, any XEcc light emitted by its CC part, and any XRsb light passing through its CC part. X light leaving each CM cell  404  via its part  406  of print area  118  is formed with XRcc light passing through its IS and DE parts, any XEcc and XRsb light passing through its IS and DE parts, any ARde light passing through its IS part, and any ARis light reflected by its IS part. This enables each CM cell  404  to temporarily appear as color X for base duration Δt drbs  as VC region  106  enters the changed state. The NA, NE, core, FE, and FA parts of each CM cell  404  here operate the same during the changed state as in OI structure  430 . 
     The DE part of each candidate cell  404  responds to the deformation along its SF DF area, and thus to object  104  impacting its SF part  406 , by deforming along an ID internal DF area constituted partly or fully with its IF part  484 . Since interface  304  is also a surface of IS component  182 , the deformation of the DE part of each candidate cell  404  along its internal DF area causes its IS part to deform. For each candidate cell  404  constituting a CM cell, its IS part responds to the deformation along its internal DF area by providing another cellular impact effect, termed the principal cellular second impact effect. The CC part of each CM cell  404  responds to its principal cellular second impact effect by causing it to further temporarily appear as color X for extension duration Δt drext . Automatic duration Δt drau  again lengthens to Δt drbs +Δt drext . The light processing in each CM cell  404  is the same during extension duration Δt drext  as during base duration Δt drbs . 
       FIGS. 49 a  and 49 b    illustrate an extension  490  of both OI structure  440  and OI structure  470 . OI structure  490 , also an embodiment of OI structure  320 , is configured the same as structure  470  except that VC region  106  here contains SF structure  242  extending from SF zone  112  to ISCC structure  132  so as to meet it along interface  244 . See  FIG. 49 a   . SF structure  242  is again configured and operable the same as in OI structure  440 . Each cell  404  consists of an SS part of SF structure  242 , the underlying ISCC part of ISCC structure  132 , and the further underlying DE part of DE structure  282 . 
     Each cell  404  here operates the same during the normal state as VC region  106  in OI structure  320 . Total ATic light of each cell  404  consists of ARic light reflected by its ISCC part, any AEic light emitted by its ISCC part, any ARde light passing through its ISCC part, and any ARsb light passing through its ISCC and DE parts. A light normally leaving each cell  404  via its SF part  406  is formed with ARic light passing through its SS part, any AEic, ARde, and ARsb light passing through its SS part, and any ARss light reflected by its SS part. 
     SF structure  242  deforms along SF DF area  122  in response to object  104  impacting OC area  116 . See  FIG. 49 b   . The attendant excess SF pressure along area  116  is transmitted through structure  242  to produce excess internal pressure along DP IF area  256 . Each cell  404  having its IF part  444  partly or fully in area  256  specifically deforms along a first cellular internal DF area constituted partly or fully with its IF part  444 , thereby becoming a candidate for a CM cell. A candidate cell  404  temporarily becomes a CM cell if the internal deformation along that cell&#39;s first internal DF area meets cellular internal DF criteria embodying the cellular TH impact criteria. The internal deformation along the first internal DF area of each CM cell  404  causes it to temporarily appear as color X for base duration Δt drbs  as the changed state begins. 
     The DE part of each candidate cell  404  responds to the deformation along its first internal DF area, and thus to the impact, by deforming along a second cellular internal DF area constituted partly or fully with its IF part  474 . Consequently, the ISCC part of each candidate cell  404  deforms along its second cellular internal DF area. If a candidate cell  404  is a CM cell, the deformation of its ISCC part along its second internal DF area causes it to further temporarily appear as color X for extension duration Δt drext . Automatic duration Δt drau  for that CM cell  404  is lengthened to Δt drbs +Δt drext . 
     Each CM cell  404  here undergoes the same changed-state light processing as in IDVC portion  138  of OI structure  320 . Total XTic light of each CM cell  404  consists of XRic light reflected by its ISCC part, any XEic light emitted by its ISCC part, any XRde light passing through its ISCC part, and any XRsb light passing through its ISCC and DE parts. X light temporarily leaving each CM cell  404  via its part  406  of print area  118  is formed with XRic light passing through its SS part, any XEic, XRde, and XRsb light passing through its SS part, and any ARss light reflected by its SS part. 
       FIGS. 50 a  and 50 b    illustrate an extension  500  of both OI structure  460  and OI structure  480 . OI structure  500 , also an embodiment of OI structure  330 , is configured the same as structure  480  except that VC region  106  here contains SF structure  242  extending from SF zone  112  to ISCC structure  132  to meet it, specifically IS component  182 , along interface  244 . See  FIG. 50 a   . Structure  242  here is configured and operable the same as in OI structure  460  and thus the same as in OI structure  440 . Each cell  404  consists of an SS part of SF structure  242 , an ISCC part of ISCC structure  132 , and a DE part of DE structure  302 , the ISCC part being formed with (a) an IS part of IS component  182  located below the SS part and above the DE part (b) a CC part of CC component  184  located below the DE part. Each cell&#39;s CC part is formed with an NA part of NA layer  204 , an NE part of NE structure  224 , a core part of core layer  222 , an FE part of FE structure  226 , and an FA part of FA layer  206  deployed as in OI structure  480 . 
     Each cell  404  here operates the same during the normal state as VC region  106  in OI structure  330 . Total ATcc light of each cell  404  consists of ARcc light reflected by its CC part, any AEcc light emitted by its CC part, and any ARsb light passing through its CC part. Total ATic light normally leaving the IS part of each cell  404 , and thus its ISCC part, via its IF part  444  consists of ARcc light passing through its IS and DE parts, any AEcc and ARsb light passing through its IS and DE parts, any ARde light passing through its IS part, and any ARis light reflected by its IS part. A light normally leaving each cell  404  via its SF part  406  is formed with ARcc light passing through its SS part, any AEcc, ARis, ARde, and ARsb light passing through its SS part, and any ARss light reflected by its SS part. Each cell&#39;s NA, NE, core, FE, and FA parts here operate the same during the normal state as in OI structure  460  and hence as in OI structure  430 . 
     SF structure  242  here again deforms along SF DF area  122  in response to the impact. See  FIG. 50 b   . As in OI structure  270 , the attendant excess SF pressure along OC area  116  is transmitted through SF structure  242  to produce excess internal pressure along DP IF area  256 . Because internal PS surface  244  is a surface of IS component  182 , it deforms along area  256 . Each cell  404  having its IF part  444  partly or fully in area  256  specifically deforms along a first cellular internal DF area constituted partly or fully with its IF part  444  so as to become a candidate for a CM cell. A candidate cell  404  again temporarily becomes a CM cell if the deformation along that cell&#39;s first internal DF area meets cellular internal DF criteria embodying the cellular TH impact criteria. The IS part of each CM cell  404  provides a cellular impact effect, again termed the principal cellular first impact effect. Responsive to the principal cellular first impact effect, the CC part of each CM cell  404  changes so that it temporarily appears as color X for base duration Δt drbs  as the changed state begins. 
     The DE part of each candidate cell  404  responds to the deformation along its first internal DF area, and thus to object  104  impacting its SF part  406 , by deforming along an ID second cellular internal DF area constituted partly or fully with its IF part  484 . Accordingly, the ISCC part of each candidate cell  404  deforms along its second cellular internal DF area. If a candidate cell  404  is a CM cell, its IS part responds to the deformation along its second internal DF area by providing another cellular impact effect, again termed the principal cellular second impact effect. The CC part of each CM cell  404  responds to its principal cellular second impact effect by causing it to further temporarily appear as color X for extension duration Δt drext . Automatic duration Δt drau  is again lengthened to Δt drbs +Δt drext . 
     Each CM cell  404  here undergoes the same changed-state light processing as in IDVC portion  138  of OI structure  330 . Total XTcc light of each CM cell  404  consists of XRcc light reflected by its CC part, any XEcc light emitted by its CC part, and any XRsb light passing through its CC part. Total XTic light leaving the IS part of each CM cell  404 , and thus its ISCC part, via its IF part  444  consists of XRcc light passing through its IS and DE parts, any AEcc and ARsb light passing through its IS and DE parts, any ARde light passing through its IS part, and any ARis light reflected by its IS part. X light leaving each CM cell  404  via its part  406  of print area  118  is formed with XRcc light passing through its SS part, any XEcc, ARis, ARde, and XRsb light passing through its SS part, and any ARss light reflected by its SS part. The NA, NE, core, FE, and FA parts of each CM cell  404  here operate the same during the changed state as in OI structure  460  and thus as in OI structure  430 . The light processing in each CM cell  404  is again the same during both durations Δt drbs  and Δt drext . 
       FIG. 51  presents a more detailed side cross section of a typical embodiment  510  of ISCC structure  132  in OI structure  410 ,  440 ,  470 , or  490 . With ISCC structure  510  allocated into a multiplicity of ISCC parts, one for each cell  404 , each ISCC part is indicated by reference symbol  512 . Each ISCC cell part  512  has a lateral (side) part boundary  514 , indicated in dotted line, extending along that part&#39;s “length” from a near part area  516  to a far part area  518 . Each near part area  516  constitutes a portion of SF zone  112  in OI structure  410  or  470  or a portion of interface  244  in OI structure  440  or  490 . Each far part area  518  constitutes a portion of interface  136  in structure  410  or  440  or a portion of interface  284  in structure  470  or  490 . 
     Each ISCC cell part  512  contains a central ISCC cell sector  522  having a lateral (side) sector boundary  524  extending along that sector&#39;s length from a near sector area  526  to a far sector area  528 . Sector area  526  or  528  in each cell part  512  constitutes a portion of its part area  516  or  518 . Lateral boundary  524  of each central ISCC cell sector  522  usually extends perpendicular to its sector area  526  or  528 . Sector area  526  or  528  in each cell  404  is smaller than its part  406  of SF zone  112  and usually outwardly conforms laterally to its SF part  406 . 
     An isolating region  532  of ISCC structure  510  laterally separates ISCC cell sectors  522  from one another along at least parts of their lengths. ISCC isolating region  532  specifically laterally surrounds sectors  522  of interior cells  404  along at least parts of their sector lengths and extends laterally at least partly around sectors  522  of peripheral cells  404  likewise along at least parts of their sector lengths. In the example of  FIG. 51 , isolating region  532  fully laterally surrounds every cell sector  522  along its entire length. Region  532  can, however, extend along parts of the sector lengths so that adjacent sectors  522  adjoin one another along the remainders of their sector lengths. Region  532 , which typically consists of insulating material but can be open space or a combination of open space and insulating material, usually laterally electrically insulates (or isolates) sectors  522  from one another to the extent that region  532  extends along the sector lengths. 
     A different portion  534  of isolating region  532  is allocated to each ISCC cell part  512  and extends along its ISCC sector  522  such that isolating portions  534  of adjoining cell parts  512  merge seamlessly into one another. Each part  512  is formed with its sector  522  and its isolating portion  534 . Isolating portion  534  of each cell part  512  specifically extends from its lateral sector boundary  524  to its lateral part boundary  514  and from a near isolating area  536  to a far isolating area  538 . In the example of  FIG. 51 , each near isolating area  536  constitutes part of SF zone  112  in OI structure  410  or  470  or part of interface  244  in OI structure  440  or  490  while each far isolating area  538  constitutes part of interface  136  in structure  410  or  440  or part of interface  284  in structure  470  or  490 . Area  516  or  518  of each cell part  512  consists of its sector area  526  or  528  and its isolating area  536  or  538 . 
     Sector area  526  or  528  in each ISCC cell part  512  is of much greater area than its isolating area  536  or  538 . The CC characteristics of each cell  404  are largely determined by its ISCC sector  522 . In this regard, lateral part boundaries  514  are usually defined such that lateral boundary  514  of each cell part  512  is spaced apart from, and thus lies around typically concentrically, its lateral sector boundary  524 . Light striking SF part  406  of each cell  404  either directly strikes its near part area  516 , as occurs in OI structure  410  or  470 , or at least partly passes through its SS part and strikes its area  516 , as occurs in OI structure  440  or  490 . During both the normal and changed states, each isolating portion  534  may reflect light, termed ARim light, which leaves it along its near isolating area  536  after striking that area  536 . ARim light can be the same as ARic or XRic light or significantly differ from both ARic and XRic light. 
     The light, termed ADic* light, normally leaving each ISCC cell sector  522  via its near sector area  526  after being reflected or/and emitted by that sector  522  consists of (a) light, termed ARic* light, normally reflected by that sector  522  so as to leave it via its area  526  after striking its area  526  and (b) light (if any), termed AEic* light, normally emitted by that sector  522  so as to leave it via its area  526 . ADic* light excludes any ARsb light and, in OI structures  470  and  490 , any ARde light. 
     ADic light leaving each ISCC cell part  512  via its near part area  516  during the normal state consists of ADic* and ARim light leaving it respectively via its near areas  526  and  536 . To the extent that ADic* and ARim light differ, areas  516  are preferably sufficiently small that the standard human eye/brain interprets the combination of ADic* and ARim light as a single species of light. Because near sector area  526  in each cell part  512  is much larger than its near isolating area  536 , ADic light normally provided by each cell part  512  consists largely of its ADic* light. ARic light is largely ARic* light while any AEic light is AEic* light. 
     Each cell  404  meeting the cellular TH impact criteria and temporarily becoming a CM cell, sometimes also requiring that the below-described principal supplemental impact criteria be met, undergoes changes by which light, termed XDic* light, materially different from A, ADic, and ADic* light leaves its ISCC sector  522  via its near sector area  526  during the changed state after being reflected or/and emitted by that sector  522 . XDic* light consists of (a) light, termed XRic* light, temporarily reflected by that sector  522  so as to leave it via its area  526  after striking its area  526  and (b) light (if any), termed XEic* light, temporarily emitted by that sector  522  so as to leave it via its area  526 . XDic* light excludes any XRsb light and, in OI structures  470  and  490 , any XRde light. 
     XDic light leaving ISCC cell part  512  of each CM cell  404  via its near part area  516  during the changed state consists of XDic* and ARim light leaving it respectively via its near areas  526  and  536 . To the extent that XDic* and ARim light differ, the standard human eye/brain interprets the combination of XDic* and ARim light as a single species of light if, as preferably occurs, the standard human eye/brain interprets the combination of ADic* and ARim light as a single species of light. Since near sector area  526  in each cell part  512  is much larger than its near isolating area  536 , XDic light temporarily provided by cell part  512  of each CM cell  404  consists largely of its XDic* light. XRic light is largely XRic* light while any XEic light is XEic* light. Because XDic* light differs materially from ADic* light, XDic light differs materially from ADic light even though both of them include ARim light. 
     Determination of both total ATic light normally leaving each ISCC cell part  512  via its near part area  516  and total XTic light temporarily leaving part  512  of each CM cell  404  via its area  516  involves spatial mixing of any light reflected by substructure  134  and, if present, DE structure  282  and becomes quite complex. Nevertheless, the relationship between ATic and XTic light is the same as the relationship between ADic and XDic light. Because XDic* light differs materially from ADic* light, XTic light differs materially from ATic light. X light differs materially from A light even though both of them include ARim light. 
     Each ISCC cell sector  522  can be embodied as a single material formed with IS CR or CE material such as piezochromic or piezochromic luminescent/piezoluminescent material. Sector  522  of each CM cell  404  then operates the same during the changed state as ID segment  142  of ISCC structure  132  in OI structure  130  when ISCC structure  132  is embodied as a single material formed with IS CR or CE material. 
       FIG. 52  presents a more detailed side cross section of a typical embodiment  540  of ISCC structure  132  in OI structure  420  or  450 . ISCC structure  540  is also an embodiment of ISCC structure  510 . Each ISCC cell part  512  here consists of (a) an IS part  542  of IS component  182  and (b) a CC part  544  of CC component  184 . Each IS part  542  contains a central IS cell sector  552  formed with the portion of that part&#39;s ISCC cell sector  522  in IS component  182 . Each CC part  544  contains a central CC cell sector  554  formed with the portion of that part&#39;s cell sector  522  in CC component  184 . 
     Light striking near sector areas  526  passes at least partly through IS parts  542  and strikes interface  186 . The light, termed ADcc* light, normally leaving each central CC cell sector  554  via a part  556  of interface  186  after being reflected or/and emitted by that sector  554  consists of (a) light, termed ARcc* light, normally reflected by that sector  554  so as to leave it via its IF part  556  after striking its part  556  and (b) light (if any), termed AEcc* light, normally emitted by that sector  554  so as to leave it via its IF part  556 . ADcc* light excludes any ARsb light. 
     ADcc* light provided by CC sector  554  of each cell  404  passes in substantial part through its central IS sector  552 . Including any ARis light reflected by sector  552  of each cell  404  and any ARim light reflected by its isolating portion  534 , ADic light normally leaving its ISCC cell part  512  via its near part area  516  here consists of ADcc* light and any ARis and ARim light. Areas  516  are preferably sufficiently small that the standard human eye/brain interprets ADcc* light combined with any ARis and ARim light as a single species of light. Because near sector area  526  in each cell part  512  is much larger than its near isolating area  536 , ADic light normally provided by each cell part  512  here consists largely of ADcc* light and any ARis light. ARic light is largely ARcc* light combined with any ARis light while any AEic light is AEcc* light. 
     IS sector  552  of each cell  404  meeting the cellular TH impact criteria provides its cellular impact effect so that it temporarily becomes a CM cell directly or upon the supplemental impact criteria also being met if they are used. CC sector  554  of each CM cell  404  responds either to its cellular impact effect or to a cellular CC initiation signal, or cellular CC control signal, generated if the supplemental impact criteria are met by changing so that light, termed XDcc* light, materially different from A, ADic, ADic*, ADcc, and ADcc* light leaves its sector  554  via its IF part  556  during the changed state after being reflected or/and emitted by its sector  554 . XDcc* light consists of (a) light, termed XRcc* light, temporarily reflected by each sector  554  so as to leave it via its IF part  556  after striking its part  556  and (b) light (if any), termed XEcc* light, temporarily emitted by that sector  554  so as to leave it via its IF part  556 . XDcc* light excludes any XRsb light. 
     XDcc* light provided by CC sector  554  of each CM cell  404  passes in substantial part through its IS sector  552 . Including any ARis light reflected by sector  552  of each CM cell  404  and any ARim light reflected by its isolating portion  534 , XDic light temporarily leaving its ISCC cell part  512  via its near part area  516  consists of XDcc* light and any ARis and ARim light. The standard human eye/brain interprets XDcc* light combined with any ARis and ARim light as a single species of light if, as preferably occurs, the standard human eye/brain interprets ADcc* light combined with any ARis and ARim light as a single species of light. Since near sector area  526  in each cell part  512  is much larger than its near isolating area  536 , XDic light temporarily provided by cell part  512  of each CM cell  404  consists largely of XDcc* light and any ARis light. XRic light is largely XRcc* light combined with any ARis light while any XEic light is XEcc* light. Because XDcc* light differs materially from ADcc* light, XDic light differs materially from ADic light even though both of them again include ARim light. For the reasons presented above in regard to  FIG. 51 , total XTic light temporarily leaving cell part  512  of each CM cell  404  differs materially from total ATic light normally leaving each cell part  512 . X light differs materially from A light. 
     IS sector  552  of each cell  404  can be implemented the same as IS component  182  in  FIG. 24 a    so as to consist of piezoelectric structure ( 374 ) for providing that cell&#39;s cellular impact effect as at least a cellular electrical effect resulting from excess pressure of object  104  impacting OC area  116 . Alternatively, sector  552  of each cell  404  can be implemented the same as component  182  in  FIG. 24 b    so as to consist of piezoelectric structure ( 374 ) and effect-modifying structure ( 376 ). The piezoelectric structure provides an initial cellular electrical effect resulting from excess pressure of the impact if it causes that cell  404  to meet the cellular TH impact criteria. The effect-modifying structure modifies the initial electrical effect to produce a modified cellular electrical effect as at least part of that cell&#39;s cellular impact effect. 
     CC sector  554  of each cell  404  can be embodied in any of the ways described above for embodying CC component  184 . For instance, each sector  554  can be embodied as reduced-size CR CC structure in the same way that component  184  is embodied as a CR CC component. Sector  554  of each cell  404  then normally reflects light having at least a majority component of wavelength for color A for causing that cell  404  to normally appear as color A. Sector  554  of each CM cell  404  responds (a) in some cellular OI embodiments to its cellular impact effect for the impact meeting its cellular TH impact criteria or (b) in other cellular OI embodiments to its cellular CC control signal generated in response to its impact effect sometimes dependent on other criteria also being met in those other embodiments by temporarily reflecting light having at least a majority component of wavelength for color X for causing that CM cell  404  to temporarily appear as color X. 
     Each CC sector  554  can alternatively be embodied as reduced-size CE CC structure in the same way that CC component  184  is embodied as a CE CC component. If so, sector  554  of each CM cell  404  responds (a) in some cellular OI embodiments to its cellular impact effect or (b) in other cellular OI embodiments to its cellular CC control signal generated in response to its impact effect sometimes dependent on both its cellular TH impact criteria and other criteria being met by temporarily emitting light having at least a majority component of wavelength for color X for causing that CM cell  404  to temporarily appear as color X. In this case, sector  554  of each cell  404  may normally either reflect or emit light having at least a majority component of wavelength for color A for causing that cell  404  to normally appear as color A. 
       FIG. 53  presents a more detailed side cross section of a typical embodiment  560  of ISCC structure  132  in OI structure  430  or  460 . ISCC structure  560  is also an embodiment of ISCC structure  540 . Each ISCC cell part  512  here consists of IS part  542  and CC part  544  formed with an AB part  562  of assembly  202 , an NA part  564  of NA layer  204 , an FA part  566  of FA layer  206 , and an isolating part  568  of isolating portion  534  of that cell part  512 . Isolating part  568  of each CC part  544  largely laterally surrounds its AB part  562 . Isolating region  532  thereby laterally isolates, and laterally insulates, AB parts  562  from one another. Isolating part  568  of each CC part  544  may or may not laterally surround its NA part  564  and may or may not laterally surround its FA part  566  as indicated in  FIG. 53  by dashed-line extensions of its isolating part  568  into its auxiliary parts  564  and  566 . 
     AB part  562  of each CC part  544  consists of a core section  572  of core layer  222 , a near electrode  574  of NE structure  224 , and a far electrode  576  of FE structure  226 . Electrodes  574  and  576  in each AB part  562  are situated generally opposite each other. Core section  572  in each part  562  lies at least partly between its electrodes  574  and  576 . In the example of  FIG. 53 , all of section  572  in each part  562  lies between its electrodes  574  and  576 . Layer  222  consists of sections  572  and the laterally adjacent material of isolating region  532 . NE structure  224  consists of near electrodes  574  and the laterally adjacent material of region  532 . FE structure  226  consists of far electrodes  576  and the laterally adjacent material of region  532 . Electrodes  574  and  576  usually adjoin region  532  along their entire lateral peripheries. 
     Electrodes  574  and  576  in each cell  404  are respectively at controllable voltages V n  and V f  so that control voltage V nf  equal to voltage difference V n −V f  is applied across that cell&#39;s core section  572 . Voltages V n  and V f  for each cell  404  are normally at respective normal control values V nN  and V fN  so that its electrodes  574  and  576  normally apply normal control value V nfN  across that cell&#39;s core section  572 . This enables light having at least a majority component of wavelength for color A to normally leave section  572  of each cell  404  along its near electrode  574 . Each cell  404  normally appears as color A. 
     A cellular CC voltage is provided for each CM cell  404  directly in response to its cellular impact effect provided by its IS sector  552  or from a CC initiation signal generated in response to the supplemental impact criteria, if used, being met. Providing the cellular CC voltage for each CM cell  404  entails changing its control voltage V nf  to changed value V nfC  materially different from its normal value V nfN . When provided directly in response to the cellular impact effect, the cellular CC voltage of each CM cell  404  can be generated by various parts of that CM cell  404 , e.g., by its sector  552  or by a portion, such as its NA part  564 , of its CC part  544 . Core section  572  of each CM cell  404  responds to its cellular CC voltage by enabling light having at least a majority component of wavelength for color X to temporarily leave that CM cell  404  along its near electrode  574 . Each CM cell  404  temporarily appears as color X. 
     Determination of both total ATcc light normally leaving CC part  544  of each cell  404  via its IF part  424  and total XTcc light temporarily leaving part  544  of each CM cell  404  via its IF part  424  during the changed state becomes quite complex due to spatial mixing of light variously provided by its cell parts  564 ,  566 ,  568 ,  572 ,  574 , and  576  and any light reflected by substructure  134  and, if present, DE structure  282 . However, by arranging for parts  564 ,  566 ,  572 ,  574 , and  576  of each cell  404  to operate so that XDcc* light differs materially from ADcc* light, XTcc light differs materially from ATcc light. Total XTic light then differs materially from total ATcc light so that X light differs materially from A light even though both of them again include ARim light. 
     ISCC structure  132  in OI structure  480  or  500  can be embodied the same as ISCC structure  560  except that DE structure  302  lies between components  182  and  184 . A DE part of structure  302  then lies between parts  542  and  544  of each cell  404 . By arranging for parts  564 ,  566 ,  572 ,  574 , and  576  of each cell  404  to operate so that XDcc* light differs materially from ADcc* light, XTcc light differs materially from ATcc light. Total XTic light again differs materially from total ATcc light so that X light differs materially from A light. 
     IS part  542 , auxiliary parts  564  and  566 , core section  572 , and electrodes  574  and  576  in each cell  404  can respectively be embodied in any of the ways described above for embodying IS component  182 , auxiliary layers  204  and  206 , core layer  222 , and electrode structures  224  and  226  subject to (a) structures  224  and  226  being embodied as electrodes, (b) the general impact effect provided by component  182  being embodied as the cellular impact effect provided by that cell&#39;s IS sector  552 , and (c) the general CC control signal applied to structures  224  and  226  being embodied as the cellular CC voltage applied to that cell&#39;s electrodes  574  and  576 . 
     As one example, core section  572  of each cell  404  consists of a supporting medium and a multiplicity of particles distributed in the medium. The particles in each cell  404  normally reflect ARcl light such that ATcl light formed with the ARcl light and any FE-structure-reflected ARfe light passing through layer that cell&#39;s section  572  is a majority component of A light. The particles in each CM cell  404  translate or/and rotate in response to the cellular CC voltage so as to temporarily reflect XRcl light such that total XTcl light formed with XRcl light and any FE-segment-reflected XRfe light passing through that cell&#39;s section  572  is a majority component of X light. ARcl and XRcl light are usually respective majority components of A and X light. 
     As another example, core section  572  of each cell  404  contains a liquid normally in a first cell-liquid shape for causing that cell&#39;s section  572  to reflect ARcl light such that ATcl light formed with the ARcl light and any FE-structure-reflected ARfe light passing through that cell&#39;s section  572  is a majority component of A light. The liquid in each CM cell  404  changes to a second cell-liquid shape materially different from the first cell-liquid shape in response to the cellular CC voltage. This causes section  572  of each CM cell  404  to temporarily reflect XRcl light so that total XTcl light formed with XRcl light and any FE-segment-reflected XRfe light passing through that cell&#39;s section  572  is a majority component of X light. 
     The cell architecture of OI structure  400  has various advantages. The boundary of print area  118  defined by cell SF parts  406  is clear. The color can change along SF part  406  of any cell  404  without changing color along SF part  406  of any neighboring cell  404  not intended to undergo color change. The ambit of materials suitable for implementing OI structure  100  is increased because there is no need to limit VC region  106 , especially IS component  182 , to materials for which the effect of the impact does not laterally spread significantly beyond OC area  116 . Any desired print accuracy can be achieved by adjusting linear density N L  of cells  404  in the row and column directions. If the cellular TH impact criteria are intended to vary along SF zone  112 , neighboring cells  404  can readily be provided with different cellular TH impact criteria. Different shades of the embodiments of colors A and X occurring in the absence of ARis light can be created by varying the reflection characteristics of the IS parts, specifically the wavelength and intensity characteristics of ARis light, without changing the CC parts. 
     Adjustment of Changed-State Duration 
       FIGS. 54 a  and 54 b    present block diagram/layout views of an information-presentation structure  600  consisting of OI structure  100  and a principal general CC duration controller  602  for adjusting duration Δt dr  of the changed state subsequent to impact. “IP” hereafter means information-presentation. A network  604  of communication paths extends from VC region  106  to general CC duration controller  602  in IP structure  600 . “COM” hereafter means communication. See  FIG. 54 a   . A network  606  of COM paths extends from controller  602  back to region  106 . In the absence of adjustment caused by controller  602 , CC duration Δt dr  would be at a preset value equal to automatic value Δt drau . 
     Controller  602  responds to external instruction  608  and to object  104  impacting OC area  116  by controlling the IDVC portion ( 138 ), specifically the ID ISCC segment ( 142 ), to adjust CC duration Δt dr . See  FIG. 54 b   . The resultant adjusted value Δt dradj  of duration Δt dr  differs from automatic value Δt drau . Duration Δt dr  is usually lengthened. Adjusted value Δt dradj  is then greater than automatic value Δt drau , typically greater than the high end of the principal pre-established CC duration range mentioned above. Duration Δt dr  can be shortened so that adjusted value Δt dradj  is less than value Δt drau , typically less than the low end of the principal Δt dr  range. In either case, external instruction  608  is supplied to controller  602  after duration Δt dr  begins, i.e., after the color change occurs, and before automatic value Δt drau  would otherwise terminate. After duration Δt dr  ends, controller  602  automatically returns the preset value of duration Δt dr  to automatic value Δt drau  in preparation for the next impact. 
     Instruction  608 , formed with one or more individual instructions, can cause CC duration Δt dr  to continue in various time-dependent ways. Instruction  608  can be provided essentially instantaneously to controller  602  for causing duration Δt dr  to continue for a selected time increment after which duration Δt dr  automatically terminates. If it is desired that duration Δt dr  extend beyond this termination point, instruction  608  can be renewed prior to the expected termination so that duration Δt dr  continues for another such time increment after which duration Δt dr  again automatically terminates. The instruction renewal process can, if desired, continue indefinitely or be limited to a prescribed number of renewals. 
     Instruction  608  can be generated so that CC duration Δt dr  continues indefinitely until instruction  608  changes in a way intended to cause duration Δt dr  to terminate. For example, instruction  608  can be continuously supplied to controller  602  for causing duration Δt dr  to continue until instruction  608  ceases being supplied to controller  602 . Alternatively, instruction  608  can be supplied essentially instantaneously in one form to controller  602  for causing duration Δt dr  to continue indefinitely. Instruction  608  is later supplied essentially instantaneously to controller  602  in another form for causing duration Δt dr  to terminate. 
     In some embodiments of IP structure  600 , instruction  608  can be furnished to controller  602  after automatic value Δt drau  of duration Δt dr  ends and thus after the IDVC portion ( 138 ) has started returning to appearing as principal color A, usually provided that controller  602  receives instruction  608  no later than a specified time period after impact at time t ip , after object separation is just completed at OS time t os , or after duration Δt dr  begins at forward XN end time t fe . The IDVC portion then returns to appearing as changed color X in accordance with instruction  608 . After the so-interrupted version of duration Δt dr  finally ends, controller  602  again automatically returns the preset value of duration Δt dr  to automatic value Δt drau . 
     Typically human originated, instruction  608  can be furnished in various ways to controller  602 . A person can manually address one or more instruction-input elements, such as sliders, keys, switches or/and buttons, on controller  602  to provide it with instruction  608 . A person can manually touch a touch-sensitive area of controller  602  with an instructing object to provide it with instruction  608 . The instructing object can be a finger or other part of the person&#39;s body or an electronic instructing object. Controller  602  can have a sensitive area, e.g., capacitively sensitive, for receiving instruction  608  by having a person bring an instructing object, again such as a finger or other part of the person&#39;s body or an electronic instructing object, suitably close to, but not necessarily in contact with, the sensitive area. A person can generate instruction  608  by using a radiation-emitting element to direct radiation such as light or IR radiation onto a radiation-sensitive area of controller  602 . 
     Instruction  608  can be provided to controller  602  by human voice. Controller  602  can be coded to respond (a) only to the voice of a selected person or any person in a selected group of people and thus not interpret any other such voice or sound as instruction  608  or/and (b) only to selected words and therefore not interpret any other word(s) as instruction  608 . Controller  602  can receive instruction  608  via a remote device in communication with controller  602 . A person can provide instruction  608  to the remote device in any of the ways, including by human voice, for providing instruction  608  directly to controller  602 . The remote device converts that instruction into instruction  608  and transmits it to controller  602  via a COM path. Also, instruction  608  can be provided to other CC controllers described below in any way for providing instruction  608  to controller  602 . 
     IP structure  600  operates as follows. The IDVC portion ( 138 ) temporarily appears as color X if the impact of object  104  on OC area  116  meets the principal basic TH impact criteria. When VC region  106  includes structure besides the ISCC structure ( 132 ), the ID ISCC segment ( 142 ) specifically causes the IDVC portion to temporarily appear as color X if the basic TH impact criteria are met. The IDVC portion, specifically the ISCC segment, provides a principal general location-identifying impact signal in response to the impact if it meets the basic TH impact criteria. “LI” hereafter means location-identifying. The general LI impact signal, transmitted via COM network  604  to controller  602 , identifies the location of print area  118  along SF zone  112 . This identification usually arises because the origination of the impact signal from the ISCC segment provides information identifying where the IDVC portion is located laterally in region  106  and thus where area  118  is located in zone  112 . 
     If controller  602  receives instruction  608 , controller  602  responds to instruction  608  and to the general LI impact signal by providing a principal general CC duration signal transmitted via COM network  606  to the IDVC portion ( 138 ), specifically the ID ISCC segment ( 142 ), for adjusting CC duration Δt dr  subsequent to impact. The IDVC portion responds to the general CC duration signal by continuing to appear as color X in accordance with instruction  608 . When VC region  106  contains structure besides the ISCC structure ( 132 ), the ISCC segment specifically causes the IDVC portion to continue appearing as color X in accordance with instruction  608 . If instruction  608  later changes to a form intended to cause duration Δt dr  to terminate, the IDVC portion returns to appearing as color A. If instruction  608  is not supplied to controller  602 , the IDVC portion simply returns to appearing as color A when automatic value Δt drau  expires. 
       FIGS. 55-58  present composite block diagrams/side cross sections.  FIG. 55  illustrates an embodiment  610  of IP structure  600  responding to instruction  608 . IP structure  610  is also an extension of OI structure  130  to include controller  602 . VC region  106  here consists solely of ISCC structure  132  in which IDVC portion  138 /ISCC segment  142  supplies the general LI impact signal to controller  602  via network  604  if the basic TH impact criteria are met and receives the general CC duration signal from controller  602  via network  606 . Subject to portion  138 /segment  142  supplying the impact signal and receiving the duration signal, region  106 /structure  132  here usually contains components  182  and  184  as in OI structure  180 . 
       FIG. 56  depicts an embodiment  620  of IP structure  600  responding to instruction  608 . IP structure  620  is also an extension of OI structure  200  to include controller  602 . VC region  106  here consists solely of ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206 . ID segments  214 ,  234 ,  232 ,  236 , and  216  of subcomponents  204 ,  224 ,  222 ,  226 , and  206  are not labeled in  FIG. 56  due to spacing limitations. See  FIG. 12 b    for identifying segments  214 ,  234 ,  232 ,  236 , and  216  in  FIG. 56 . 
     IS segment  192  supplies the LI impact signal to controller  602  via network  604  if the basic TH impact criteria are met. Electrode segments  234  and  236  of CC segment  194  receive the general CC duration signal from controller  602  via network  606 . The duration signal causes voltage V nf  for IDVC portion  138 /ISCC segment  142  to be maintained at changed value V nfC  or sufficiently close to it that CC duration Δt dr  continues in accordance with instruction  608 . Subject to IS segment  192  supplying the impact signal and CC segment  194  receiving the duration signal, components  182  and  184  here can be embodied in any way described above for embodying them in OI structure  200 . 
       FIG. 57  depicts an embodiment  630  of IP structure  600  responding to instruction  608 . IP structure  630  is also an extension of OI structure  240  to include controller  602  and an extension of IP structure  610  to include SF structure  242 . VC region  106  here consists of ISCC structure  132  and SF structure  242 . ISCC structure  132  and controller  602  here are configured, operate, and interact the same as in IP structure  610 . SF structure  242  here is configured and functions the same as in OI structure  240 . When ISCC structure  132  functions as a PSCC structure, ISCC segment  142  supplies the general LI impact signal to controller  602  if the excess internal pressure along DP IF area  256  meets the excess internal pressure criteria that embody the basic TH impact criteria. 
     An IP structure formed with controller  602  and OI structure  280  containing ISCC structure  132  and DE structure  282  can be implemented in the same way as IP structure  630 . An IP structure formed with controller  602  and OI structure  320  containing ISCC structure  132 , SF structure  242 , and DE structure  282  can also be implemented in the same way as IP structure  630 . 
       FIG. 58  depicts an embodiment  640  of IP structure  600  responding to instruction  608 . IP structure  640  is also an extension of OI structure  270  to include controller  602  and an extension of IP structure  620  to include SF structure  242 . VC region  106  here thus includes ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206 . See  FIG. 12 b    for identifying their ID segments  214 ,  234 ,  232 ,  236 , and  216  not labeled in  FIG. 58  due to spacing limitations. Components  182  and  184  and controller  602  here are configured, operate, and interact the same as in IP structure  620 . SF structure  242  here is configured and functions the same as in OI structure  270 . When ISCC structure  132  functions as a PSCC structure, IS segment  192  supplies the LI impact signal to controller  602  if the excess internal pressure criteria are met. 
     An IP structure formed with controller  602  and OI structure  300  containing DE structure  302  and ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206  can be implemented the same as IP structure  640  except that DE structure  302  lies between components  182  and  184 . An IP structure formed with controller  602  and OI structure  330  containing SF structure  242 , DE structure  302 , and ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206  can also be implemented the same as IP structure  640  again except that DE structure  302  lies between components  182  and  184 . 
       FIGS. 59 a  and 59 b    present block diagram/layout views of an IP structure  650  consisting of OI structure  400  and a principal cell CC duration controller  652  responsive to instruction  608  for adjusting CC durations Δt dr  of CM cells  404 , i.e., cells  404  in ID group  138 *. IP structure  650  is also an embodiment of IP structure  600  for which cell CC duration controller  652  embodies general duration controller  602 . Referring to  FIG. 59 a   , a network  654  of COM paths extends from all cells  404  to controller  652 . A network  656  of COM paths extends from controller  652  back to all cells  404 . Each COM network  654  or  656  usually includes a set of row COM paths, each connected to a different row of cells  404 , and a set of column COM paths, each connected to a different column of cells  404 . Absence adjustment caused by controller  652 , duration Δt dr  for each cell  404  would be at a preset value equal to automatic value Δt drau  for that cell  404 . Automatic value Δt drau  for each cell  404  from impact to impact lies in a cellular CC duration range the same as the principal CC duration range. 
     Each CM cell  404 , i.e., each cell  404  meeting the principal cellular TH impact criteria, responds to object  104  impacting OC area  116  by providing a principal cellular LI impact signal, transmitted via network  654  to controller  652 , identifying that cell&#39;s location along SF zone  112 . See  FIG. 59 b    which only shows the parts of networks  654  and  656  used by CM cells  404 . The same is done in later  FIGS. 60-63 . The location identification usually arises because the origination of the cellular LI impact signal from each CM cell  404  identifies where its SF part  406  is located in zone  112 . When VC region  106  includes structure besides the ISCC structure ( 132 ), the ISCC part of each CM cell  404  specifically provides that cell&#39;s LI impact signal. The cellular LI impact signals of all CM cells  404  embody the general LI impact signal identifying the location of print area  118  along zone  112  in IP structure  600 . 
     If controller  652  receives instruction  608 , controller  652  responds to instruction  608  and to the cellular LI impact signal of each CM cell  404  by providing a principal cellular CC duration signal, transmitted via network  656  to that cell  404  specifically its ISCC part, for adjusting its CC duration Δt dr  subsequent to impact. Controller  652  usually creates the cellular CC duration signals by producing a general CC duration signal and suitably splitting it. The adjusted value Δt dradj  of duration Δt dr  for each CM cell  404  differs from its automatic value Δt drau . Duration Δt dr  for each CM cell  404  is usually lengthened. Adjusted value Δt dradj  for each CM cell  404  is then greater than its value Δt drau , typically greater than the high end of the principal CC duration range. Duration Δt dr  for each CM cell  404  can be shortened so that its adjusted value Δt dradj  is less than its value Δt drau , typically less than the low end of the principal Δt dr  range. In either case, instruction  608  is supplied to controller  652  before value Δt drau  for any CM cell  404  would otherwise terminate. 
     Each CM cell  404  responds to its cellular CC duration signal by continuing to appear as color X in accordance with instruction  608 . When VC region  106  contains structure besides the ISCC structure ( 132 ), the ISCC part of each CM cell  404  specifically causes it to continue appearing as color X. If instruction  608  later changes to a form intended to cause CC duration Δt dr  of each CM cell  404  to terminate, it returns to appearing as color A. Controller  652  controls all CM cells  404  in unison so that they all receive their duration signals at largely one time and all return to appearing as color A at largely another later time. If instruction  608  is not supplied to controller  652 , each CM cell  404  simply returns to appearing as color A when its automatic CC duration value Δt drau  expires. After duration Δt dr  ends, controller  652  automatically returns the preset value of duration Δt dr  of each CM cell  404  to its automatic value Δt drau  to prepare for the next impact. 
       FIGS. 60-63  present composite block diagrams/side cross sections.  FIG. 60  depicts an embodiment  660  of IP structure  650  responding to instruction  608 . IP structure  660  is also an extension of OI structure  410  to include controller  652 . VC region  106  here consists solely of ISCC structure  132  in which each CM cell  404 /its ISCC part supplies its cellular LI impact signal to controller  652  via network  654  and receives its cellular CC duration signal from controller  652  via network  656 . Subject to each CM cell  404 /its ISCC part supplying its impact signal and receiving its duration signal, each cell  404 /its ISCC part here usually contains IS and CC parts as in OI structure  420 . 
       FIG. 61  depicts an embodiment  670  of IP structure  650  responding to instruction  608 . IP structure  670  is also an extension of OI structure  430  to include controller  652 . VC region  106  here is formed solely with ISCC structure  132  consisting of IS component  182  and CC component  184  formed with subcomponents  204 ,  224 ,  222 ,  226 , and  206 . Hence, each cell  404 /its ISCC part here consists of an IS part and a CC part formed with individual NA, NE, core, FE, and FA parts. 
     The IS part of each CM cell  404  supplies its LI impact signal to controller  652  via network  654 . The electrode parts of the CC part of each CM cell  404  receive its CC duration signal from controller  652  via network  656 . The duration signal for each CM cell  404  causes its control voltage V nf  to be maintained at, or sufficiently close to, changed value V nfC  that its CC duration Δt dr  continues in accordance with instruction  608 . Subject to the IS part of each CM cell  404  supplying its impact signal and its CC part receiving its duration signal, the IS and CC parts of each cell  404  here can be embodied in any way described above for embodying them in OI structure  430 . 
       FIG. 62  depicts an embodiment  680  of IP structure  650  responding to instruction  608 . IP structure  680  is also an extension of OI structure  440  to include controller  652  and an extension of IP structure  660  to include SF structure  242 . VC region  106  here consists of ISCC structure  132  and overlying SF structure  242 . ISCC structure  132  and controller  652  here are configured, operate, and interact the same as in IP structure  660 . SF structure  242  here is configured and functions the same as in OI structure  440 . When ISCC structure  132  functions as a PSCC structure, each cell  404  for which the excess internal pressure along its IF part  444  meets the cellular excess internal pressure criteria embodying the cellular TH impact criteria becomes a CM cell whose IS part supplies that cell&#39;s LI impact signal to controller  652  and whose CC part receives that cell&#39;s CC duration signal from controller  652 . 
     An IP structure formed with controller  652  and OI structure  470  containing ISCC structure  132  and DE structure  282  can be implemented in the same way as IP structure  680 . An IP structure formed with controller  652  and OI structure  490  containing ISCC structure  132 , SF structure  242 , and DE structure  282  can also be implemented in the same way as IP structure  680 . 
       FIG. 63  depicts an embodiment  690  of IP structure  650  responding to instruction  608 . IP structure  690  is also an extension of OI structure  460  to include controller  652  and an extension of IP structure  670  to include SF structure  242 . VC region  106  here thus consists of ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206 . Components  182  and  184  and controller  652  here are configured, operate, and interact the same as in IP structure  670 . SF structure  242  here is configured and functions the same as in OI structure  460 . When ISCC structure  132  functions as a PSCC structure, each cell  404  meeting the cellular excess internal pressure criteria becomes a CM cell. 
     An IP structure formed with controller  652  and OI structure  480  containing DE structure  302  and ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206  can be implemented the same as IP structure  690  except that DE structure  302  lies between components  182  and  184 . An IP structure formed with controller  652  and OI structure  500  containing SF structure  242 , DE structure  302 , and ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206  can also be implemented the same as IP structure  690  again except that DE structure  302  lies between components  182  and  184 . 
     Intelligent Color-Change Control 
       FIGS. 64 a  and 64 b    present block diagram/layout views of an IP structure  700  consisting of OI structure  100  and a principal general intelligent CC controller  702  for providing a supplemental impact assessment capability to determine whether an impact meeting the principal basic TH impact criteria has certain principal supplemental impact characteristics and, if so, for causing the IDVC portion ( 138 ) to temporarily appear as color X. The supplemental assessment capability enables IP structure  700  to distinguish between impacts of object  104  on SF zone  112  for which color change at print area  118  is desired and impacts of bodies on zone  112  for which color change is not desired. General intelligent CC controller  702  is also capable of adjusting CC duration Δt dr  subsequent to impact the same as duration controller  602 . A network  704  of COM paths extends from VC region  106  to controller  702 . See  FIG. 64 a   . A network  706  of COM paths extends from controller  702  back to region  106 . In addition, structure  700  contains network  606  usually at least partly overlapping COM network  706 . 
     The IDVC portion ( 138 ), specifically the ID ISCC segment ( 142 ), provides a principal general characteristics-identifying impact signal in response to object  104  impacting OC area  116  if the impact meets the basic TH impact criteria. See  FIG. 64 b   . “CI” hereafter means characteristics-identifying. The general CI impact signal, transmitted via COM network  704  to controller  702 , identifies principal general characteristics of the impact. The general impact characteristics consist of the location expected for print area  118  in SF zone  112  and principal general supplemental impact information for the impact on OC area  116 . The identification of the expected PA location usually arises because the origination of the CI impact signal from the ISCC segment provides information identifying where the IDVC portion is laterally located in VC region  106  and thus where area  118  is expected to be located in zone  112 . 
     Controller  702  responds to the general CI impact signal by determining whether the general supplemental impact information meets (or satisfies) principal supplemental impact criteria and, if so, provides a principal general CC initiation signal transmitted via network  706  to the IDVC portion ( 138 ), specifically the ID ISCC segment ( 142 ). The IDVC portion responds to the general CC initiation signal, which implements the principal general CC control signal, by temporarily appearing as color X. When VC region  106  includes structure besides the ISCC structure ( 132 ), the ISCC segment specifically causes the IDVC portion to temporarily appear as color X. An impact on SF zone  112  thus must meet principal expanded impact criteria consisting of the basic TH impact criteria and the supplemental impact criteria to cause a temporary color change. 
     IP structure  700  is able to distinguish between impacts of object  104  for which color change is desired and impacts of other bodies for which color change is not desired so that color change occurs only for suitable impacts of object  104 . The time period taken by controller  702  to determine whether the principal supplemental impact criteria are met and, if so, to produce the initiation signal is very short, usually several ms or less. Approximate full forward XN delay Δt f  is still usually no more than 2 s, preferably no more than 1 s, more preferably no more than 0.5 s, even more preferably no more than 0.25 s. 
     Controller  702  may receive instruction  608 . If so and if the supplemental impact criteria are met, controller  702  responds to instruction  608  by providing the general CC duration signal transmitted via network  606  to the IDVC portion ( 138 ), specifically the ID ISCC segment ( 142 ), for adjusting CC duration Δt dr  subsequent to impact as described above for IP structure  600 . 
     The general supplemental impact information usually includes the size and/or shape expected for print area  118  if the IDVC portion ( 138 ) changes to temporarily appear as color X. The supplemental impact criteria then include corresponding static size and/or shape criteria for area  118 . The PA size criteria preferably include a maximum reference area value A prh  for the expected area A pr  of area  118 , “PA” again meaning print-area. Controller  702  provides the ID ISCC segment ( 142 ) with the general CC initiation signal only when expected PA area A pr  is less than or equal to maximum PA reference area value A prh . The size criteria may include a minimum reference area value A prl  for PA area A pr  if area  118  is expected to be located fully in SF zone  112 . If so, controller  702  provides the ISCC segment with the initiation signal when PA area A pr  is greater than or equal to minimum PA reference area value A prl  provided that area  118  is expected to be located fully in zone  112 . The PA shape criteria preferably include (a) a reference shape for area  118  and (b) a shape parameter set consisting of at least one shape parameter defining variations from the reference shape. Controller  702  provides the ISCC segment with the initiation signal only when the expected shape of area  118  falls within the shape parameter set. 
     The general supplemental impact information may include duration Δt oc  of object  104  in contact with OC area  116  and thus in contact with the expected location of print area  118 . The supplemental impact criteria then include OC time duration criteria. The OC duration criteria may include a minimum reference OC duration value Δt ocrl  for area  118  located fully in SF zone  112 . If so, controller  702  provides the ID ISCC segment ( 142 ) with the general CC initiation signal when duration Δt oc  is greater than or equal to minimum reference OC duration value Δt ocrl  provided that area  118  is expected to be located fully in zone  112 . Small particles whose OC durations Δt oc  are less than reference OC duration value Δt ocrl  do not cause color change even if they impact surface  102  hard enough to meet the basic TH impact criteria. 
     The OC duration criteria may alternatively or additionally include a maximum reference OC time duration value Δt ocrh . Controller  702  then provides the ID ISCC segment ( 142 ) with the CC initiation signal only when OC duration Δt oc  is less than or equal to maximum reference OC duration value Δt ocrh . For example, OC duration Δt oc  is nearly always less than 25 ms when object  104  is a typical hollow sports ball such as a tennis ball, basketball, or volleyball that bounces off surface  102  after impacting it. Duration Δt oc  is typically 4-5 ms, and thus invariably less than 10 ms, for a served or returned tennis ball moving over a tennis court whose playing surface embodies surface  102 . Duration Δt oc  is typically in the vicinity of 15 ms for a basketball being dribbled on a basketball court whose playing surface embodies surface  102 . 
     In contrast, the time period during which a shoe on a foot of a person is in continuous contact with surface  102  as the person moves over surface  102  is nearly always greater than 50 ms. The shoe/foot contact time for a person running over a hard floor or other hard surface is reportedly a at least 80 ms, typically 100-200 ms or more, for elite runners. Consequently, the shoe/foot contact time for a person running over a hard surface is considerably greater than typical duration Δt oc  of no more than 25 ms for a tennis ball or basketball. By choosing maximum reference OC duration value Δt ocrh  to be suitably greater than 5 ms for a tennis ball or suitably greater than 15 ms for a basketball but suitably less than the time period during which either shoe of a person contacts surface  102  as the person moves over it, e.g., reference value Δt ocrh  can be set at a value from 10 ms up to at least 50 ms, possibly up to 75 ms, for a tennis ball or at a value from 20 ms likewise up to at least 50 ms, possibly up to 75 ms, for a basketball, color changes occur when tennis balls or basketballs impact surface  102  but largely not when the shoes of people impact surface  102 . Color changes similarly occur when the shoes of people impact surface  102  but largely not when tennis balls or basketballs impact surface  102  by choosing maximum reference OC duration value Δt ocrh  to be suitably greater than the time period during which either shoe of a person contacts surface  102  as the person moves over it, e.g., reference value Δt ocrh  can be set at a value of more than 75 ms such as 80, 90, or 100 ms. 
     The supplemental impact criteria may cover various time-varying phenomena. In this regard, OC area  116  is the maximum area where object  104  contacts SF zone  112  during the impact. However, the area where object  104  contacts zone  112  during the impact usually varies with time, reaching area  116  at some instant during OC duration Δt oc . Let contact area  116 * be the time-varying instantaneous area which spans where object  104  contacts zone  112  and for which the basic TH impact criteria are met. Instantaneous TH-meeting contact area  116 *, which most closely approaches OC area  116  at some instant during duration Δt oc , is of an instantaneous area A oc *. 
     With the foregoing in mind, the general supplemental impact information may include instantaneous area A oc *. The size criteria then include a plurality of maximum reference area values A ocrh * for successive instants separated by selected time periods. Controller  702  provides the ID ISCC segment ( 142 ) with the CC initiation signal only when instantaneous area A oc * is less than or equal to the maximum reference area value A ocrh * for each of a selected group of the successive instants during which object  104  is in contact with SF zone  112 . The supplemental impact information may similarly include the instantaneous shape for TH-meeting contact area  116 *. If so, the shape criteria include a plurality of reference shapes for successive instants separated by selected time periods and (b) a like plurality of sets of at least one shape parameter respectively defining variations from the reference shapes for the successive instants. Controller  702  provides the ISCC segment with the initiation signal only when the instantaneous shape of contact area  116 * falls within the shape parameter set for each of a selected group of the successive instants while object  104  is in contact with zone  112 . 
     The color that the IDVC portion ( 138 ) would appear along print area  118  during OC duration Δt oc  if area  118  were externally exposed during duration Δt oc  is generally immaterial because the presence of object  104  on OC area  116  usually prevents any person from then seeing area  118 . An impact meeting the basic TH impact criteria but insufficient to meet the supplemental impact criteria can cause the IDVC portion to change to a condition in which it would appear along area  118  as changed color X, or some other color, during duration Δt oc  if area  118  were then externally exposed as long as the IDVC portion largely returns to its normal-state condition as principal color A at or prior to the end of duration Δt oc . 
     Similar to the basic TH impact criteria, the supplemental impact criteria can consist of multiple sets of fully different principal supplemental impact criteria respectively associated with different specific (or specified) changed colors materially different from principal color A. More than one, usually all, of the specific changed colors again differ, usually materially. The supplemental impact information is potentially capable of meeting (or satisfying) any of the supplemental impact criteria sets. If the supplemental impact information meets the supplemental impact criteria, generic changed color X is the specific changed color for the criteria set actually met by the supplemental impact information. The supplemental impact criteria sets sometimes form a continuous chain in which consecutive criteria sets meet each other without overlapping. 
     The supplemental impact criteria for the expected shape of print area  118  can consist of multiple sets of expected shapes for area  118 , each set of PA shape criteria associated with a specific changed color materially different from color A. Each PA shape criteria set preferably includes (a) a reference shape for area  118  and (b) a shape parameter set consisting of at least one shape parameter defining variations from the reference shape. The reference shapes all differ. Letting R toc  represent the OC range from minimum reference OC duration value Δt ocrl  to maximum reference OC duration value Δt och , the supplemental impact criteria for values Δt ocrl  and Δt ocrh  can consist of multiple sets of non-overlapping OC ranges R toc , each R toc  range similarly associated with a specific changed color materially different from color A. Provided that there are at least two different changed colors, changed color X is the specific changed color for the expected PA shape criteria met by the expected PA shape in the supplemental impact information or for the OC duration range R toc  met by OC duration Δt oc  in the supplemental impact information. 
     The supplemental impact criteria sets can sometimes be mathematically described as follows in terms of a supplemental parameter Q akin to impact parameter difference ΔP. Letting n again be an integer greater than 1, n principal supplemental impact criteria sets T 1 , T 2 , . . . T n  are respectively associated with n specific changed colors materially different from principal color A and with n progressively increasing low-limit supplemental parameter values Q l,1 , Q l,2  . . . . Q l,n . Each low-limit supplemental parameter value Q l,i , except lowest-numbered value Q l,1 , thereby exceeds next-lowest-numbered value Q l,i−1  where integer i again varies from 1 to n. 
     Each supplemental criteria set T 1 , except highest-numbered criteria set T n , is defined by the requirement that parameter Q equal or exceed low-limit supplemental parameter value Q l,i  but be no greater than an infinitesimal amount below a higher supplemental parameter value Q h,i  less than or equal to next higher low-limit supplemental parameter value Q l,i+1 . Each criteria set T i , except set T n , is a Q range R i  extending between a low limit equal to low-limit value Q l,i  and a high limit an infinitesimal amount below high-limit value Q h,i . Highest-numbered criteria set T n  is defined by the requirement that parameter Q equal or exceed low-limit supplemental parameter value Q l,n  but not exceed a higher supplemental parameter value Q h,n . Consequently, highest-numbered set T n  is a Q range R n  extending between a low limit equal to low-limit value Q l,n  and a high limit equal to high-limit value Q h,n . 
     High-limit value Q h,i  for each range R i , except highest range R n , usually equals low-limit value Q l,i+1  for next higher range R n+1 . In that case, criteria sets T 1 -T n  substantially cover a total Q range extending continuously from lowest low-limit value Q l,1  to highest high-limit value Q h,n . Supplemental parameter Q is potentially capable of meeting any of criteria sets T 1 -T n . If the general supplemental impact information meets the supplemental impact criteria, changed color X is the specific changed color for criteria set T i  actually met by parameter Q. 
     This mathematical formulation can be used to embody the supplemental impact criteria sets as fully different PA size criteria sets expected for print area  118  and as fully different OC time duration sets for OC time duration Δt oc . In particular, high-limit supplemental parameter values Q h,1 -Q h,n  can respectively be n different values of maximum reference area value A prh  for area  118  or n different values of maximum reference duration Δt ocrh  for duration Δt oc  subject to deleting the infinitesimal amount limitations. Provided that area  118  is expected to be located fully in SF zone  112 , low-limit supplemental parameter values Q l,i -Q l,n  can respectively be n different values of minimum reference area value A pd  for area  118  or n different values of minimum reference OC duration Δt ocrl  for duration Δt oc . Because each size or OC duration criteria set T i  is a range R i , these supplemental impact criteria implementations of different A prh  or Δt ocrh  values and different A prl  or Δt ocrl  values accomplish the same result. 
     Use of supplemental impact criteria sets provides a capability to distinguish between different types of impacts, specifically between different embodiments of object  104  as it impacts SF zone  112 . For example, if one embodiment of object  104  is shaped considerably differently than another embodiment of object  104  or usually contacts zone  112  for a considerably different Δt oc  value than the other object embodiment, appropriate choice of the supplemental impact criteria sets enables IP structure  700  to distinguish between the two object embodiments as they contact zone  112 . Taking note that a tennis ball embodying object  104  usually creates print area  118  of considerably different shape than a shoe of a person embodying object  104  and that a tennis ball and a person&#39;s shoe usually impact zone  112  for considerably different Δt oc  values, the supplemental impact criteria sets can readily be chosen in suitable shape parameter sets or/and OC duration range R toc  set to provide a different specific changed color X for an impact of a tennis ball than for an impact of a person&#39;s shoe or other body of considerably different impact characteristics than a tennis ball. 
     Controller  702  can provide the general CC initiation signal in various ways for causing the IDVC portion ( 138 ) to temporarily appear as the specific changed color X for the supplemental impact criteria set met by the supplemental impact information. For example, the initiation signal can be providable at a value falling into multiple different ranges respectively corresponding to the different supplemental criteria sets. Providing the initiation signal at a value falling into one of these ranges due to the supplemental impact information meeting the supplemental impact criteria for that range then causes the IDVC portion to temporarily appear as the specific changed color X for that range. Alternatively, the initiation signal can consist of multiple general CC initiation subsignals respectively corresponding to the different supplemental criteria sets. Each general CC initiation subsignal goes to an enable condition when the supplemental impact information meets the supplemental impact criteria for that subsignal and is otherwise at disable condition so that no more than one of the initiation subsignals can be at its enable condition at any time. Causing one of the initiation subsignals to go to its enable condition due to the supplemental impact information meeting the supplemental impact criteria for that subsignal causes the IDVC portion to temporarily appear as the specific changed color X for that subsignal. 
       FIGS. 65-68  present composite block diagrams/side cross sections.  FIG. 65  depicts an embodiment  710  of IP structure  700  responding to instruction  608 . IP structure  710  is also an extension of OI structure  130  to include controller  702 . VC region  106  here consists solely of ISCC structure  132  in which IDVC portion  138 /ISCC segment  142  supplies the general CI impact signal to controller  702  via network  704  if the basic TH impact criteria are met and receives the general CC initiation and duration signals from controller  702  respectively via networks  706  and  606  if the supplemental impact criteria are met. Subject to portion  138 /segment  142  supplying the impact signal and receiving the initiation and duration signals, region  106 /structure  132  usually contains components  182  and  184  as in OI structure  180 . 
       FIG. 66  depicts an embodiment  720  of IP structure  700  responding to instruction  608 . IP structure  720  is also an extension of OI structure  200  to include controller  702 . VC region  106  is here formed solely with ISCC structure  132  consisting of IS component  182  and CC component  184  formed with subcomponents  204 ,  224 ,  222 ,  226 , and  206 . ID segments  214 ,  234 ,  232 ,  236 , and  216  of subcomponents  204 ,  224 ,  222 ,  226 , and  206  are not labeled in  FIG. 66  due to spacing limitations. See  FIG. 12 b    for identifying segments  214 ,  234 ,  232 ,  236 , and  216  in  FIG. 66 . 
     IS segment  192  supplies the general CI impact signal to controller  702  via network  704  if the basic TH impact criteria are met. Electrode segments  234  and  236  of CC segment  194  receive the general CC initiation and duration signals from controller  702  respectively via networks  706  and  606  if the supplemental impact criteria are met. The initiation signal causes voltage V nf  for IDVC portion  138 /ISCC segment  142  to go to changed value V nfC  for causing portion  138  to temporarily appear as color X. Since the time period taken by controller  702  to determine that the general supplemental impact information meet the supplemental impact criteria is usually several ms or less, full forward XN delay Δt f  still can be as high as 0.4 s, sometimes as high as 0.6, 0.8, or 1.0 s but again is usually reduced to no more than 0.2 s, preferably no more than 0.1 s, more preferably no more than 0.05 s, even more preferably no more than 0.025 s. The duration signal causes voltage V nf  for portion  138 /segment  142  to be maintained at, or sufficiently close to, value V nfC  that CC duration Δt dr  continues in accordance with instruction  608 . Subject to IS segment  192  supplying the impact signal and CC segment  194  receiving the initiation and duration signals, components  182  and  184  here can be embodied in any way described above for embodying them in OI structure  200 . 
       FIG. 67  depicts an embodiment  730  of IP structure  700  responding to instruction  608 . IP structure  730  is also an extension of OI structure  240  to include controller  702  and an extension of IP structure  710  to include SF structure  242 . VC region  106  here thus consists of ISCC structure  132  and SF structure  242 . ISCC structure  132  and controller  702  here are configured, operate, and interact the same as in IP structure  710 . SF structure  242  here is configured and functions the same as in OI structure  240 . When ISCC structure  132  functions as a PSCC structure, ISCC segment  142  supplies the general CI impact signal to controller  702  if the excess internal pressure along DP IF area  256  meets the excess internal pressure criteria. 
     An IP structure formed with controller  702  and OI structure  280  containing ISCC structure  132  and DE structure  282  can be implemented in the same way as IP structure  730 . An IP structure formed with controller  702  and OI structure  320  containing ISCC structure  132 , SF structure  242 , and DE structure  282  can also be implemented in the same way as IP structure  730 . 
       FIG. 68  depicts an embodiment  740  of IP structure  700  responding to instruction  608 . IP structure  740  is also an extension of OI structure  270  to include controller  702  and an extension of IP structure  720  to include SF structure  242 . VC region  106  here thus consists of ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206 . See  FIG. 12 b    for identifying their ID segments  214 ,  234 ,  232 ,  236 , and  216  not labeled in  FIG. 68  due to spacing limitations. Components  182  and  184  and controller  702  here are configured, operate, and interact the same as in IP structure  720 . SF structure  242  here is configured and functions the same as in OI structure  270 . When ISCC structure  132  functions as a PSCC structure, IS segment  192  supplies the general CI impact signal to controller  702  if the excess internal pressure criteria are met. 
     An IP structure formed with controller  702  and OI structure  300  containing DE structure  302  and ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206  can be implemented the same as IP structure  740  except that DE structure  302  lies between components  182  and  184 . An IP structure formed with controller  702  and OI structure  330  containing SF structure  242 , DE structure  302 , and ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206  can also be implemented the same as IP structure  740  again except that DE structure  302  lies between components  182  and  184 . 
       FIGS. 69 a  and 69 b    present block diagram/layout views of an IP structure  750  consisting of OI structure  400  and a principal intelligent cell CC controller  752  for providing a supplemental impact assessment capability to determine whether an impact meeting the principal cellular TH impact criteria has certain supplemental impact characteristics and, if so, for causing CM cells  404  to temporarily appear as color X. IP structure  750  is also an embodiment of IP structure  700  for which intelligent cell CC controller  752  embodies general intelligent CC controller  702 . Referring to  FIG. 69 a   , a network  754  of COM paths extends from all cells  404  to controller  752 . A network  756  of COM paths extends from controller  752  back to all cells  404 . Each COM network  754  or  756  usually includes a set of row COM paths, each connected to a different row of cells  404 , and a set of column COM paths, each connected to a different column of cells  404 . IP structure  750  further contains network  656  usually at least partly overlapping network  756 . 
     Each cell  404  meeting the cellular TH impact criteria temporarily becomes a TH CM cell and responds to object  104  impacting OC area  116  by providing a principal cellular CI impact signal, transmitted via network  754  to controller  752 , identifying principal cellular characteristics for the impact as experienced at that cell  404 . See  FIG. 69 b   . Multiple cells  404  virtually always temporarily become TH CM cells. The principal cellular impact characteristics for each TH CM cell  404  consist of the location of its SF part  406  in SF zone  112  and principal cellular supplemental information for the impact. The location identification usually arises because the origination of the cellular CI impact signal from each TH CM cell  404  identifies where its SF part  406  is located in zone  112 . When VC region  106  contains structure besides the ISCC structure ( 132 ), the ISCC part of each TH CM cell  404  specifically provides that cell&#39;s CI impact signal. The cellular CI impact signals of all TH CM cells  404  embody the general CI impact signal in IP structure  700 . 
     Controller  752  responds to the cellular CI impact signals by combining the principal cellular supplemental impact information of all TH CM cells  404  to form the principal general supplemental impact information and then determining whether it meets the supplemental impact criteria. If so, each TH CM cell  404  temporarily becomes a full CM cell. For each full CM cell  404 , controller  752  provides a principal cellular CC initiation signal transmitted via network  756  to that cell  404  specifically its ISCC part.  FIG. 69 b    only shows the parts of networks  754 ,  756 , and  656  used by full CM cells  404 . The same is done in later  FIGS. 70-73 . Each full CM cell  404  responds to its cellular CC initiation signal, which implements its cellular CC control signal, by temporarily appearing as color X. When VC region  106  includes structure besides the ISCC structure ( 132 ), the ISCC part of each full CM cell  404  specifically causes it to temporarily appear as color X. ID cell group  138 * embodying IDVC portion  138  consists of full CM cells  404 . The cellular CC initiation signals of all full CM cells  404  embody the general CC initiation signal in IP structure  700 . 
     The principal expanded impact criteria that must be met to cause a temporary color change consist of the cellular TH impact criteria and the supplemental impact criteria. Controller  752  usually creates the cellular CC initiation signals by producing a principal general CC initiation signal and suitably splitting it. The cellular CC initiation signals provided to all full CM cells  404  embody the general CC initiation signal in IP structure  700 . 
     If the supplemental impact criteria consist of multiple sets (T 1 -T n ) of different principal supplemental impact criteria respectively associated with multiple specific changed colors (X i -X n ) materially different from principal color A, controller  752  responds to the cellular impact signal of each TH CM cell  404  by providing it, specifically its ISCC part, with a cellular CC initiation signal that causes it to temporarily become a full CM cell and temporarily appear as the specific changed color (X i ) for the supplemental criteria set actually met by the supplemental impact information. 
     Controller  752  may receive instruction  608 . If so and if the general supplemental impact information meets the supplemental impact criteria, controller  752  responds to instruction  608  by providing, for each full CM cell  404 , a principal cellular CC duration signal, transmitted via network  656  to that cell  404  specifically its ISCC part, for adjusting that cell&#39;s CC duration Δt dr  subsequent to impact the same as in IP structure  650 . Each full CM cell  404  responds to its cellular CC duration signal by continuing to appear as color X in accordance with instruction  608 . When VC region  106  contains structure besides the ISCC structure ( 132 ), the ISCC part of each full CM cell  404  specifically causes it to continue appearing as color X in accordance with instruction  608 . Controller  752  usually creates the cellular CC duration signals by producing a general CC duration signal and suitably splitting it. 
       FIGS. 70-73  present composite block diagrams/side cross sections.  FIG. 70  depicts an embodiment  760  of IP structure  750  responding to instruction  608 . IP structure  760  is also an extension of OI structure  410  to include controller  752 . VC region  106  here consists solely of ISCC structure  132  in which each TH CM cell  404 /its ISCC part supplies its cellular CI impact signal to controller  752  via network  754  and in which each full CM cell  404 /its ISCC part receives its cellular CC initiation and duration signals from controller  752  respectively via networks  756  and  656 . Subject to each TH CM cell  404 /its ISCC part supplying its impact signal and each full CM cell  404 /its ISCC part receiving its initiation and duration signals, each cell  404 /its ISCC part here usually contains IS and CC parts as in OI structure  420 . 
       FIG. 71  depicts an embodiment  770  of IP structure  750  responding to instruction  608 . IP structure  770  is also an extension of OI structure  430  to include controller  752 . VC region  106  here is formed solely with ISCC structure  132  consisting of IS component  182  and CC component  184  formed with subcomponents  204 ,  224 ,  222 ,  226 , and  206 . Each cell  404 /its ISCC part here consists of an IS part and a CC part formed with individual NA, AB, and FA parts, each AB part being formed with individual NE, core, and FE parts. 
     The IS part of each TH CM cell  404  supplies its cellular CI impact signal to controller  752  via network  754 . The electrode parts of each full CM cell  404  receive its cellular CC initiation and duration signals from controller  752  respectively via networks  756  and  656 . The initiation signal for each full CM cell  404  causes its control voltage V nf  to go to changed value V nfC  for causing it to temporarily appear as color X. The duration signal for each full CM cell  404  causes its voltage V nf  to be maintained at, or sufficiently close to, value V nfC  that its CC duration Δt dr  continues in accordance with instruction  608 . Subject to the IS part of each TH CM cell  404  supplying its impact signal and the CC part of that full CM cell  404  receiving its initiation and duration signals, the IS and CC parts of each cell  404  here can be embodied in any of the ways described above for embodying those parts in OI structure  430 . 
       FIG. 72  depicts an embodiment  780  of IP structure  750  responding to instruction  608 . IP structure  780  is also an extension of OI structure  440  to include controller  752  and an extension of IP structure  760  to include SF structure  242 . VC region  106  here consists of ISCC structure  132  and overlying SF structure  242 . ISCC structure  132  and controller  752  here are configured, operate, and interact the same as in IP structure  760 . SF structure  242  here again is configured and functions the same as in OI structure  440 . When ISCC structure  132  functions as a PSCC structure, each cell  404  for which the excess internal pressure along its IF part  444  meets the cellular excess internal pressure criteria becomes a TH CM cell whose IS part supplies that cell&#39;s CI impact signal to controller  752 . The CC part of each full CM cell  404  receives its CC initiation and duration signals from controller  752 . 
     An IP structure formed with controller  752  and OI structure  470  containing ISCC structure  132  and DE structure  282  can be implemented in the same way as IP structure  780 . An IP structure formed with controller  752  and OI structure  490  containing ISCC structure  132 , SF structure  242 , and DE structure  282  can likewise be implemented in the same way as IP structure  780 . 
       FIG. 73  depicts an embodiment  790  of IP structure  750  responding to instruction  608 . IP structure  790  is also an extension of OI structure  460  to include controller  752  and an extension of IP structure  770  to include SF structure  242 . VC region  106  here consists of ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206 . Components  182  and  184  and duration controller  602  here are configured, operate, and interact the same as in IP structure  770 . SF structure  242  here again is configured and functions the same as in OI structure  460 . When ISCC structure  132  functions as a PSCC structure, each cell  404  meeting the cellular excess internal pressure criteria temporarily becomes a TH CM cell and, if the supplemental impact criteria are met, a full CM cell. 
     An IP structure formed with controller  752  and OI structure  480  containing DE structure  302  and ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206  can be implemented the same as IP structure  790  except that DE structure  302  lies between components  182  and  184 . An IP structure formed with controller  752  and OI structure  500  containing SF structure  242 , DE structure  302 , and ISCC structure  132  formed with IS component  182  and CC component  184  consisting of subcomponents  204 ,  224 ,  222 ,  226 , and  206  can also be implemented the same as IP structure  790  again except that DE structure  302  lies between components  182  and  184 . 
     Controller  752  may provide a PA shape correction capability. As indicated above, the general supplemental impact information received by controller  752  via the cellular CI impact signals from TH CM cells  404  meeting the cellular TH impact criteria usually includes the shape expected for print area  118 . The supplemental impact criteria then include static shape criteria for area  118 . In determining that the shape information sufficiently satisfies the shape criteria so that each TH CM cell  404  becomes a full CM cell, controller  752  may determine that one or more nearby cells  404  not meeting the cellular TH impact criteria should undergo color change to better present area  118  in view of the shape criteria. If so, the PA shape correction capability is performed by having controller  752  provide a principal cellular CC initiation signal, transmitted via network  756 , to the ISCC part of each such nearby cell  404  for causing it to temporarily appear as color X. If controller  752  receives instruction  608 , controller  752  provides each such nearby cell  404  with a principal cellular CC duration signal, transmitted via network  656 , to the ISCC part of that cell  404  for adjusting its CC duration Δt dr  subsequent to impact. 
     The supplemental impact assessment capability furnished by intelligent controller  702  or  752  enables each of IP structures  700 ,  710 ,  720 ,  730 , and  740  or  750 ,  760 ,  770 ,  780 , and  790  to accurately and quickly distinguish between impacts of object  104  for which color change is desired and impacts of bodies for which color change is not desired so as to provide color change only for suitable impacts of object  104 . The size, shape, and/or OC duration criteria can be chosen to cause color change when a ball impacts SF zone  112  sufficiently hard but not when a shoe of a person impacts zone  112  as arises with tennis lines, and vice versa as arises with the three-point lines in basketball. The supplemental impact assessment capability for any impact is usually performed in a very small part of a second, usually no more than 0.1 s, preferably no more than 10 ms, more preferably no more than 5 ms. Hence, a color change at print area  118  seems to occur almost simultaneously with the impact as seen by a person. Also, the size and/or shape criteria, both static and time-varying, may vary with where area  118  is located in zone  112 . 
     The supplemental impact criteria sometimes require that print area  118  be entirely inside SF zone  112 . This is typically expressed by the physical requirement that area  118  be spaced apart from interface  110  and each other part of the boundary of zone  112 . For this purpose, controller  702  or  752  may maintain an electronic map of zone  112 , including the location of the edge of interface  110  along surface  102  and each other part of the boundary of zone  112 . The general supplemental impact information includes the location of OC area  116  on the map. Controller  702  or  752  determines the expected location of print area  118  from the OC-area location and examines the map to determine whether area  118  is entirely inside zone  112 . 
     Image Generation and Object Tracking 
       FIG. 74  illustrates an IP structure  800  consisting of OI structure  100  and an image-generating system  802  for generating images (or pictures) of print area  118  and selected adjoining SF area. “IG” hereafter means image-generating. The images can be used, e.g., by persons, to examine where area  118  occurs in SF zone  112 , e.g., to assist in determining how closely area  118  comes to a selected part of the boundary of zone  112 . VC region  106  here can be embodied in any way for embodying it in any of OI structures  130 ,  180 ,  200 ,  240 ,  260 ,  270 ,  280 ,  300 ,  320 ,  330 ,  340 , and  350 . 
     IG system  802  consists of IG structure  804  for generating images and an IG controller  806  for controlling IG structure  804  to suitably generate principal PA vicinity images. “PAV” hereafter means print-area vicinity. Structure  804  is formed with an image-collecting apparatus  808  for collecting images, including PAV images, and a video screen  810  for displaying the collected images. Image-collecting apparatus  808 , typically formed with one or more cameras  812 , is deployed to have a field of view that enables apparatus  808  to collect an image of any part of VC SF zone  112  as well as an adjoining part of surface  102  outside zone  112 , e.g., an adjoining part of FC SF zone  114 . A network  814  of COM paths extends from VC region  106  to IG controller  806 . 
     Each principal PAV image, usually a rectangular static (still) color image, consists of an image of print area  118  and adjacent surface extending to at least a selected location of surface  102 . The selected SF location is usually a partial boundary of SF zone  112 , e.g., the edge of interface  110  along zone  112 . Area  118  appears as an image print area on the PAV image. Each PAV image occupies an imaging area A im . The image print area occupies an imaging print area A pim . For assisting persons to rapidly see how close area  118  comes to the selected SF location, the ratio A im /A pim  of imaging area A im  to imaging print area A pim  is usually no more than 100, preferably no more than 50, more preferably no more than 25, even more preferably no more than 10. 
     The ID ISCC segment ( 142 ) provides the general LI impact signal in response to the impact if it meets the basic TH impact criteria. Responsive to the LI impact signal transmitted via COM network  814  and thus to the impact if the basic TH impact criteria are met, controller  806  provides a principal PA identification signal identifying the location of print area  118  in SF zone  112  provided that a principal IG condition, explained below, is met. The PA identification signal is transmitted via a COM path  816  to IG structure  804 , specifically image-collecting apparatus  808 . Structure  804  responds by generating a PAV image. In particular, apparatus  808  collects the PAV image, specifically the data for the PAV image, in response to the PA identification signal. The PAV-image data is transmitted via a COM path  818  to video screen  810  which displays the PAV image. Controller  806  may provide a screen activation/deactivation signal, transmitted via a COM path  820 , to screen  810  for activating or deactivating it. 
     Controller  806  can usually be selected (or set) to operate in an automatic mode or in an instruction mode for causing IG structure  804  to generate PAV images if the basic TH impact criteria are met. The mode selection is done with a mode-selection device (not shown) located on controller  806  or with a remote mode-selection device (also not shown) which communicates with controller  806  via a COM path. In the automatic mode, controller  806  responds to the LI impact signal by automatically causing structure  804  to generate a PAV image if print area  118  meets the principal distance condition that a point in area  118  be less than or equal to a selected distance away from the selected location on surface  102 . The distance condition is met when a point in area  118  is in the selected SF location. Controller  806  analyzes the impact signal to determine if the distance condition is met and, if so, provides the PA identification signal that causes structure  804  to generate the PAV image. 
     In the instruction mode, controller  806  responds to external instruction  822  prescribing that a PAV image be generated. External instruction  822  is supplied to controller  806  after CC duration Δt dr  begins and before it terminates. Typically human originated, instruction  822  can be furnished to controller  806  in any of the ways for supplying instruction  608  to controller  602 . If controller  806  receives both instruction  822  and the LI impact signal, controller  806  provides the identification signal which causes IG structure  804  to generate the PAV image. The IG condition that must be met for the identification signal to be supplied to structure  804  if the basic TH impact criteria are met thus consists of print area  118  meeting the distance condition or/and controller  806  receiving instruction  822 . 
     An electronic map of SF zone  112 , including the location of the SF edge of interface  110  and each other part of the boundary of zone  112 , may be maintained in controller  806 . Responsive to the general LI impact signal, controller  806  determines the expected location of print area  118  on the map and itself generates the data for a PAV image if the IG condition is met. When the basic TH impact criteria are met, controller  806  thus generates the PAV-image data if (a) area  118  meets the distance condition that a point in area  118  be less than or equal to a selected distance away from a selected location on surface  102  or/and (b) controller  806  receives instruction  822 . The PAV-image data includes the shape of the perimeter of area  118 , the shape of the selected location on surface  102 , and distance data defining the spatial relationship between the perimeter of area  118  and the selected SF location. Controller  806  provides the PAV-image data directly, e.g., via COM path  820 , to screen  810  which responds by generating the PAV image. The main difference between this technique for generating a PAV image and the earlier-mentioned technique for generating a PAV image is that controller  806  here directly generates the PAV-image data instead of image-collecting apparatus  808  generating the PAV-image data in response to the PA identification signal supplied from controller  806 . 
     IG controller  806  may be capable of providing a magnify/shrink signal prescribing a selected percentage of magnification or shrinkage of the image print area. IG structure  804  responds to the magnify/shrink signal by magnifying or shrinking the image print area by approximately the selected percentage. This can be done by increasing or decreasing the size of the PAV image so that it appears larger or smaller on screen  810  while maintaining ratio A im /A pim  constant or/and by increasing or decreasing the size of the image print area while maintaining the size of PAV image constant so that ratio A im /A pim  decreases or increases. 
     The magnify/shrink signal can be automatically provided by controller  806  when a selected impact condition arises. The impact condition can, for example, be the above distance condition that a point in print area  118  be less than or equal to a selected distance away from the selected location on surface  102 . Controller  806  can alternatively supply the magnify/shrink signal in response to external instruction  824 . Typically human originated, external instruction  824  can be furnished to controller  806  in any of the ways for supplying instruction  608  to controller  602 . The magnify/shrink signal can be supplied to image-collecting apparatus  808  via, e.g., COM path  816 . Apparatus  808  magnifies or shrinks the image print area and supplies the resultant adjusted version of the PAV image via COM path  818  to screen  810  for it to display. Alternatively, controller  806  can supply the magnify/shrink signal directly to screen  810 , e.g., via path  820 . Screen  810  then contains a capability for providing the requisite magnification or shrinkage of the image print area. 
     Image-collecting apparatus  808  optionally functions as an object-tracking control apparatus for optically tracking the movement of object  104  over surface  102  in order to facilitate distinguishing between impacts of object  104  for which color change is desired and impacts of bodies for which color change is not desired. “OT” hereafter means object-tracking. The optical tracking entails having OT control apparatus  808  generate images of object  104  as it moves over surface  102  to form a film (or motion picture) of the object&#39;s movement relative to surface  102 . 
     In a first basic OT technique, VC region  106  is capable of being enabled to be capable of changing color at locations dependent on the object tracking. All of region  106  is normally disabled from being capable of changing color so that region  106  normally appears as principal color A. The ISCC structure ( 132 ) provides the enablable/disablable CC capability. Using trajectory-assessment software, OT control apparatus  808  estimates where object  104  is expected to impact surface  102  according to the tracked movement of object  104  and provides a principal general CC enable signal shortly prior to the impact if the tracked movement of object  104  indicates that it is expected to contact surface  102  at least partly in SF zone  112 . The general CC enable signal, transmitted via a COM path  826 A to region  106  specifically the ISCC structure, at least partly identifies an ID estimated OC area  116   # , indicated by dashed line in  FIG. 74  and in later  FIG. 75 , spanning where object  104  is so expected to contact zone  112 . Based on the size, shape, and material characteristics of object  104  and on the kinematics of the expected impact between object  104  and zone  112 , estimated OC area  116   #  is usually of roughly the same physical area as actual OC area  116  even though areas  116  and  116   #  (turn out to) differ somewhat in location along zone  112 . 
     Responsive to the CC enable signal, an ID laterally oversize portion of VC region  106  extending to an ID oversize area  828 , also indicated by dashed line in  FIGS. 74 and 75 , of SF zone  112  is temporarily enabled to be capable of changing color as the oversize portion of region  106  appears along ID oversize area  828 . When region  106  includes structure besides the ISCC structure, the ISCC structure causes the oversize portion of region  106  to be enabled to be capable of changing color. Area  828 , usually roughly concentric with estimated OC area  116   # , encompasses and extends beyond it. Oversize area  828  can be determined by OT control apparatus  808  and then identified by the enable signal or determined by region  106 , usually the ISCC structure, in response to the enable signal. Apparatus  808  and region  106 , specifically the ISCC structure, operate so that area  828  virtually always fully encompasses actual OC area  116 . For this purpose, the ratio of oversize area  828 , in area, to estimated OC area  116   # , in area, is usually at least 2, preferably at least 4, and usually no more than 16, preferably no more than 8. The ratio of the average diameter of area  828  to the average diameter of area  116   #  is thus usually at least √{square root over (2)}, preferably at least 2, and usually no more than 4, preferably no more than 2√{square root over (2)}. 
     The IDVC portion ( 138 ), which is included in the oversize portion of VC region  106  and is thereby temporarily enabled to be capable of changing color, responds to object  104  impacting oversize area  828  at actual OC area  116  by temporarily appearing along print area  118  as changed color X if the impact meets the basic TH impact criteria. When region  106  includes structure besides the ISCC structure, the ID ISCC segment ( 142 ) causes the IDVC portion to temporarily appear as color X. The anticipation time period Δt ant  between the instant t act  at which the oversize portion of region  106  becomes enabled to be capable of changing color and instant t ip  at which object  104  impacts surface  102  is usually no more than 200 ms, preferably no more than 100 ms, more preferably no more than 50 ms, even more preferably no more than 25 ms. The oversize portion of region  106  remains enabled to be capable of changing color throughout CC duration Δt dr , automatic value Δt drau  here unless changed in any of the ways described above, after which the IDVC portion returns to (appearing as) color A. 
     The oversize portion of VC region  106  typically automatically becomes disabled from being capable of changing color at a specified enable-end time period Δt end  after the end of CC duration Δt dr  and thus after the IDVC portion has substantially returned to color A. Enable-end time period Δt end  is usually no more than 200 ms, preferably no more than 100 ms, more preferably no more than 50 ms, even more preferably no more than 25 ms. Alternatively, the oversize portion of region  106  automatically becomes disabled from being capable of changing color at the end of CC duration Δt dr . This causes the IDVC portion to return to color A. 
     VC region  106 , specifically the ISCC structure, in the first basic OT technique typically contains components  182  and  184 . IS segment  192  responds to object  104  impacting OC area  116  by providing the general impact effect if the impact meets the basic TH impact criteria and the oversize portion of region  106  is enabled to be capable of changing color. In other words, segment  192  provides the impact effect in response to joint occurrence of the impact meeting the basic TH impact criteria and the oversize portion of region  106  being enabled to be capable of changing color. CC segment  194  responds to the impact effect by causing the IDVC portion to temporarily appear as color X. When CC component  184  contains assembly  202 , the general CC control signal applied between electrode segments  234  and  236  and largely across core segment  232  is provided by region  106  in response to the impact effect applied between a location in NE structure  224  and a location in FE structure  226  if the oversize portion of region  106  is enabled to be capable of changing color. 
     In a second basic OT technique, OT control apparatus  808  provides a principal general impact tracking signal, specifically at an impact-indicating condition, during at least part of a tracking contact time period Δt cont  extending substantially from when, approximately impact time t ip , object  104  impacts SF zone  112  to when, approximately OS time t os , object  104  leaves zone  112  according to the tracked movement of object  104 . The general impact tracking signal, which indicates that object  104  impacted zone  112 , is transmitted via COM path  826 A to the IDVC portion ( 138 ), specifically the ID ISCC segment ( 142 ). The IDVC portion responds to largely joint occurrence of the tracking signal and the impact by temporarily appearing along print area  118  as color X if the impact meets the basic TH impact criteria. When VC region  106  contains structure besides the ISCC structure, the ISCC segment causes the IVDC portion to temporarily appear as color X. 
     VC region  106 , specifically the ISCC structure, in the second basic OT technique typically contains components  182  and  184 . IS segment  192  responds to object  104  impacting OC area  116  by providing the general impact effect if the impact meets the basic TH impact criteria. CC segment  194  responds to largely joint occurrence of the tracking signal and the impact effect, e.g., to the logical AND of the tracking signal and a signal representing the effect, by causing the IDVC portion to temporarily appear as color X. When CC component  184  contains assembly  202 , the general CC control signal applied between electrode segments  234  and  236  and largely across core segment  232  is provided by region  106  in response to largely joint occurrence of the tracking signal and the impact effect which is applied between a location in NE structure  224  and a location in FE structure  226 . 
     In a third basic OT technique, the IDVC portion ( 138 ), specifically the ID ISCC segment ( 142 ), responds to object  104  impacting SF zone  112  at OC area  116  by providing a principal general LI impact signal if the impact meets the basic TH impact criteria, “LI” again meaning location-identifying. The general LI impact signal, transmitted via a COM path  826 B to OT control apparatus  808 , identifies an expected location of print area  118  in zone  112 . Using trajectory-assessment software, apparatus  808  estimates where object  104  contacted surface  102  according to the tracked movement of object  104  and provides a principal general estimation impact signal indicative of the estimated OC area spanning where object  104  is so estimated to have contacted surface  102  if the estimate of that contact is at least partly in zone  112 . Apparatus  808  then compares the LI impact signal and the general estimation impact signal. If the comparison of the LI and estimation impact signals indicates that area  118  and the estimated OC area at least partly overlap, apparatus  808  provides a principal general CC initiation signal to the IDVC portion, specifically the ISCC segment, via path  826 A. The IDVC portion responds to the general CC initiation signal by temporarily appearing along area  118  as color X. When VC region  106  contains structure besides the ISCC structure, the ISCC segment causes the IDVC portion to temporarily appear as color X in response to the initiation signal. 
     VC region  106 , specifically the ISCC structure, in the third basic OT technique typically contains components  182  and  184 . IS segment  192  responds to object  104  impacting OC area  116  by providing the general impact effect in the form of the general LI impact signal if the impact meets the basic TH impact criteria. After OT control apparatus  808  operates on the general LI and estimation impact signals to produce the general CC initiation signal, CC segment  194  responds to the initiation signal by causing the IDVC portion to temporarily appear along print area  118  as color X. When CC component  184  includes assembly  202 , the general CC control signal applied between electrode segments  234  and  236  and largely across core segment  232  is provided by region  106  in response to the impact effect applied between a location in NE structure  224  and a location in FE structure  226 . 
     Importantly, if a body not tracked by OT control apparatus  808  impacts SF zone  112  so as to meet the basic TH impact criteria in each of the three OT techniques, apparatus  808  ( i ) does not provide a general CC enable signal that leads to enablement of the CC capability in an oversize portion of VC region  106  in the first OT technique, (ii) does not provide an impact tracking signal to indicate that the body contacted zone  112  in the second OT technique, and (iii) does not provide a general CC initiation signal that leads to a color change at the location where the body contacted zone  112  in the third OT technique. No color change along zone  112  occurs where the body contacted zone  112  even though the body&#39;s impact met the TH impact criteria. Each OT technique thus enables IP structure  800  to cause color change for impacts of object  104  for which color change is desired and to avoid causing color change for impacts of bodies for which color change is not desired. 
     The need for the general LI impact signal in the first and second basic OT techniques is reduced, virtually eliminated, because the object tracking identifies object  104  and determines where it impacts SF zone  112 . IG controller  806  can sometimes be provided in simpler form to be responsive only to instructions  822  and  824 . Alternatively, controller  806  can be eliminated, instruction  822  can be directly provided to OT control apparatus  808 , and instruction  824  can be provided directly to screen  810 . 
       FIG. 75  illustrates an IP structure  830  containing OI structure  100  and IG system  802  for generating images of print area  118  and selected adjoining SF area. System  802  is again formed with IG controller  806  and IG structure  804  consisting of image-collecting apparatus  808  and screen  810 . OI structure  100  and imaging components  806 ,  808 , and  810  here are all configured, embodiable, and operable the same as in IP structure  800  except as explained below. In addition, IP structure  830  includes a principal general CC controller  832 . A network  834  of COM paths extends from VC region  106  to general CC controller  832 . COM network  834  may partly overlap network  814  for system  802 . A network  836  of COM paths extends from controller  832  back to region  106 . 
     Controller  832  can be duration controller  602  for adjusting CC duration Δt dr  subsequent to impact. COM networks  834  and  836  then respectively embody networks  604  and  606  for transmitting the general LI impact and CC duration signals for VC region  106 . Alternatively, controller  832  can be intelligent controller  702  for providing the supplemental impact assessment capability to determine whether an impact meeting the basic TH impact criteria has certain supplemental impact characteristics and, if so, for causing the IDVC portion ( 138 ) to temporarily appear as color X. The impact characteristics identified by the general CI impact signal provided by the IDVC portion, specifically the ID ISCC segment ( 142 ), upon meeting the TH impact criteria again consist of the location expected for print area  118  in SF zone  112  and the general supplemental impact information. The principal expanded impact criteria that must be met to cause a temporary color change consist of the basic TH impact criteria and the supplemental impact criteria. Networks  834  and  836  now respectively embody networks  704  and  706  for transmitting the general CI impact and CC initiation signals. For either embodiment, controller  832  responds to instruction  608  the same as controller  602  or  702 . 
     IG controller  806  can operate in various ways when controller  832  is an intelligent controller. It is sometimes desirable to generate a PAV image regardless of whether the supplemental impact criteria are, or are not, met. Controller  806  then supplies the PA identification signal in response to the expected location for print area  118  provided in the general CI impact signal. Network  814  may transmit the entire general CI impact signal to controller  806 . If so, controller  806  largely ignores the supplemental impact information. A PAV image is generated whenever the basic TH impact criteria are met. Controller  806  usually provides the PA identification signal in response to the general CC initiation signal supplied from controller  832  via a COM path  838 . In that case, a PAV image is generated only when the general supplemental impact criteria are met. 
     If image-collecting apparatus  808  functions as an OT control apparatus for optically tracking the movement of object  104  over surface  102  in IP structure  830 , there is generally considerably less need to provide the supplemental impact assessment capability for distinguishing between impacts of object  104  for which color change at print area  118  is desired and impacts of bodies for which color change is not desired because the object tracking usually inherently means that impact of object  104  on SF zone  112  is highly likely to meet the supplemental impact criteria. Use of controller  832  as an intelligent controller can often be significantly reduced or eliminated. 
     Alternatively, controller  832  performs all or part of the data processing performed by image-collecting apparatus  808  in the three OT techniques described above. Controller  832  or the combination of controller  832  and apparatus  808  then functions as an OT control apparatus. For instance, in a variation of the first OT technique, controller  832  estimates where object  104  is expected to contact surface  102  according to the tracked movement of object  104  and provides the general CC enable signal if the tracked movement indicates that object  104  is expected to contact surface  102  at least partly in SF zone  112 . Controller  832  provides the general impact tracking signal in a variation of the second OT technique. In a variation of the third OT technique, controller  832  estimates where object  104  contacted surface  102  according to the tracked movement of object  104 , provides the general estimation impact signal if object  104  is estimated to have at least partly contacted zone  112 , compares the general LI and estimation impact signals, and provides the general CC initiation signal if the comparison indicates that the estimated OC area and print area  118  at least partly overlap. 
       FIG. 76  illustrates an IP structure  840  consisting of OI structure  400  and an IG system  842  for generating images of print area  118  and selected adjoining SF area. The images can be used to examine where area  118  occurs in SF zone  112 , e.g., to see how closely area  118  comes to a selected part of the boundary of zone  112 . Structure  400  here can be embodied with any of OI structures  410 ,  420 ,  430 ,  440 ,  450 ,  460 ,  470 ,  480 ,  490 , and  500  implemented in any way described above. 
     IG system  842  consists of IG structure  804  and an IG controller  846  for controlling structure  804  to suitably generate principal PAV images. Structure  804  here consists of image-collecting apparatus  808  and screen  810  configured and operable the same as in IP structure  800 . A network  848  of COM paths extends from all cells  404  to IG controller  846 . COM network  848  usually includes a set of row COM paths, each connected to a different row of cells  404 , and a set of column COM paths, each connected to a different column of cells  404 . 
     The ISCC part of each CM cell  404  responds to object  104  impacting OC area  116  by providing the cellular LI impact signal identifying that cell&#39;s location along SF zone  112 . The cellular LI impact signal of each CM cell  404  is transmitted via network  848  to controller  846 .  FIG. 76  and later  FIG. 77  utilize solid line to show the parts of network  848  used by CM cells  404  in the illustrated example and dashed line to show the other parts of network  848 . 
     Responsive to the cellular LI impact signals from CM cells  404 , controller  846  provides a PA identification signal identifying the location of print area  118  in SF zone  112  if an IG condition is met. The PA identification signal is transmitted via path  816  to IG structure  804 , specifically image-collecting apparatus  808 . As with IG controller  806 , the IG condition consists of area  118  meeting the above-described distance condition or controller  846  receiving instruction  822 . Structure  804  here responds to the PA identification signal the same as in IP structure  800 . 
     Controller  846  can usually be selected (or set) the same as controller  806  to operate in an automatic mode or in an instruction mode for causing IG structure  804  to generate a PAV image if the basic TH impact criteria are met, controller  846  being responsive to instruction  822  in the instruction mode. Controller  846  may maintain an electronic map of SF zone  112 , including the location of the SF edge of interface  110  and each other part of the boundary of zone  112 . If so, controller  846  can generate the data for a PAV image the same as controller  806  uses such a map to generate the data for a PAV image. The PAV-image data is supplied from controller  846  directly, e.g., via path  820 , to screen  810  which displays the PAV image. The cell arrangement of VC region  106  in OI structure  400  facilitates generation of the map because SF part  406  of each cell  404  is at a different specified location on the map. Responsive to instruction  824 , controller  846  may provide a magnify/shrink signal the same as controller  806 . 
     Image-collecting apparatus  808  optionally functions as an OT control apparatus for optically tracking the movement of object  104  over surface  102  in IP structure  840  in implementations of the OT techniques described above for IP structure  800  to provide color change only for impacts of object  104  for which color change is desired. Although not shown in  FIG. 76 or 77 , path  826 A splits into a group of individual COM paths respectively extending to the ISCC parts of all cells  404 . 
     Cells  404  in an implementation of the first basic OT technique are enablable/disablable cells normally disabled from being capable of changing color as they appear along SF parts  406 . The oversize portion of VC region  106  is constituted with an ID group of cells  404  termed the oversize cell group. In  FIGS. 76 and 77 , dashed line is used to indicate the left-most edges of left-most cells  404  in the oversize cell group and to indicate the farthest-most edges of farthest-most cells  404  in the oversize cell group. Oversize area  828  consists of SF parts  406  of cells  404  in the oversize cell group. Responsive to the CC enable signal transmitted along one of COM paths  826 A, each cell  404  in the oversize cell group is enabled in to be capable of changing color. When region  106  includes structure besides the ISCC structure ( 132 ), the ISCC part of each cell  404  in the oversize cell group causes that cell  404  to be enabled to be capable of changing color. Each so-enabled cell  404  temporarily appears as changed color X if the impact of object  104  on SF zone  112  causes that cell  404  to meet the cellular TH impact criteria and temporarily become a CM cell. When region  106  contains structure besides the ISCC structure, the ISCC part of each CM cell  404  causes it to temporarily appear as color X. 
     The IDVC portion ( 138 ) in an implementation of the second basic OT technique is constituted with an ID group of cells  404 . Each cell  404  in the ID cell group responds to largely joint occurrence of the general impact tracking signal, transmitted along a corresponding one of paths  826 A, and object  104  impacting SF zone  112  by temporarily appearing as color X if the impact causes that cell  404  to meet the cellular TH impact criteria. Cells  404  in the ID group become CM cells that form ID cell group  138 *. When VC region  106  includes structure besides the ISCC structure ( 132 ), the ISCC part of each cell  404  in cell group  138 * causes that cell  404  to temporarily appear as color X. 
     In an implementation of the third basic OT technique, each of multiple cells  404  for which the impact of object  104  on that cell&#39;s SF part  406  meets the cellular TH impact criteria becomes part of a first ID group of cells  404  termed the ID expected PA cell group. Cells  404  in the ID expected PA cell group are TH CM cells. Each cell  404 , specifically its ISCC part, in the expected PA cell group provides a principal cellular LI impact signal identifying the location of its SF part  406  in SF zone  112 . Although not shown in  FIG. 76 or 77 , COM path  826 B includes a group of individual COM paths respectively extending from all cells  404 , specifically their ISCC parts, to OT control apparatus  808 . The cellular LI impact signal of each cell  404  in the expected PA cell group is provided along a corresponding one of COM paths  826 B to apparatus  808 . SF parts  406  of cells  404  in the expected PA cell group form the area expected for print area  118 . The cellular LI impact signals of all cells  404  in the expected PA cell group together form the general LI impact signal. 
     OT control apparatus  808  estimates where object  104  contacted surface  102  according to the tracked movement of object  104  and provides the general estimation impact signal to determine the estimated OC area here consisting of SF parts  406  of a second ID group of cells  404  termed the estimated-area cell group. As in IP structure  800 , apparatus  808  here determines whether the estimated OC area at least partly overlaps print area  118 . In this way, apparatus  808  determines whether any cell  404  is in both the estimated-area cell group and the expected PA cell group. If so, apparatus  808  provides the general CC initiation signal. Each cell  404  in the expected PA cell group responds to the CC initiation signal, transmitted along a corresponding one of paths  826 A, by temporarily appearing as color X. When VC region  106  includes structure besides the ISCC structure ( 132 ), the ISCC part of each cell  404  in the expected PA cell group causes that cell  404  to temporarily appear as color X. 
     If a body not tracked by OT control apparatus  808  impacts SF zone  112  so as to meet the cellular TH impact criteria in each of these implementations of the three basic OT techniques, apparatus  808  ( i ) does not provide a general CC enable signal leading to enablement of the CC capability in cells  404  in the oversize cell group in the implementation of the first OT technique, (ii) does not provide an impact tracking signal to indicate that the body contacted zone  112  in the implementation of the second OT technique, and (iii) does not provide a general CC initiation signal leading to a color change at the location where the body contacted zone  112  in the implementation of the third OT technique. No color change along zone  112  occurs where the body contacted zone  112  even though the body&#39;s impact met the cellular TH impact criteria. The implementation of each OT technique enables IP structure  840  to cause color change for impacts of object  104  for which color change is desired and to substantially avoid causing color change for impacts of bodies for which color change is not desired. There is much less need for the cellular CI impact signals in all three implementations because the object tracking identifies object  104 , thereby eliminating the need to provide general supplemental impact information for use in determining whether a body impacting zone  112  constitutes object  104 . 
       FIG. 77  illustrates an IP structure  850  containing OI structure  400  and IG system  842  for generating images of print area  118  and selected adjoining SF area. IG system  842  is again formed with IG controller  846  and IG structure  804  consisting of image-collecting apparatus  808  and screen  810 . Structure  400  and imaging components  808 ,  810 , and  846  here are all configured, embodiable, and operable the same as in IP structure  840  except as explained below. Additionally, IP structure  850  includes a principal cell CC controller  852 . A network  854  of COM paths extends from all cells  404  to cell CC controller  852 . COM network  854  may partly overlap network  848  for IG system  842 . A network  856  of COM paths extends from controller  852  back to all cells  404 . Each COM network  854  or  856  usually includes a set of row COM paths, each connected to a different row of cells  404 , and a set of column COM paths, each connected to a different column of cells  404 . 
     Controller  852  can be duration controller  652  for adjusting CC duration Δt dr  of each CM cell  404  subsequent to impact. Networks  854  and  856  then respectively embody networks  654  and  656  for transmitting the cellular LI impact and cellular CC duration signals for each CM cell  404 .  FIG. 77  utilizes solid line to show the parts of network  854  and  856  used by CM cells  404  in the illustrated example and dashed line to show the other parts of network  854  and  856 . Alternatively, controller  852  can be intelligent controller  752  for providing the supplemental impact assessment capability to determine whether an impact meeting the TH impact criteria has certain supplemental impact characteristics and, if so, for causing TH CM cells  404  to temporarily become full CM cells  404  temporarily appearing as color X. If so, the ISCC parts of TH CM cells  404  provide the cellular CI impact signals. The cellular impact characteristics for each TH CM cell  404  again consist of its location in SF zone  112  and cellular supplemental impact information. The principal expanded impact criteria that must be met to cause a temporary color change consist of the cellular TH impact criteria and the supplemental impact criteria. Networks  854  and  856  now respectively embody networks  754  and  756  for transmitting the cellular CI impact and CC initiation signals for each CM cell  404 . For either embodiment, controller  852  responds to instruction  608  the same as controller  652  or  752 . 
     IG controller  846  can operate in various ways when controller  852  is an intelligent controller. If a PAV image is desired regardless of whether the supplemental impact criteria are, or are not, met, IG controller  846  furnishes the PA identification signal in response to the expected locations for CM cells  404 , and thus print area  118 , provided in the cellular CI impact signals transmitted via network  848 . A PAV image is generated whenever the cellular TH impact criteria are met. Controller  846  usually provides the PA identification signal in response to the general CC initiation signal supplied from controller  852  via a COM path  858 . A PAV image is then generated only when the supplemental impact criteria are met. 
     If image-collecting apparatus  808  is used as an OT control apparatus for optically tracking object  104  over surface  102  in IP structure  850 , the need for the supplemental impact assessment capability is less because the object tracking usually inherently means that impact of object  104  on SF zone  112  is highly likely to meet the supplemental impact criteria. Use of controller  852  as an intelligent controller can often be significantly reduced or eliminated. Alternatively, controller  852  performs all or part the data processing performed by apparatus  808  in the implementations of the three OT techniques similar to how controller  832  alternatively performs all or part the data processing performed by apparatus  808  in the three OT techniques. Controller  852  or the combination of controller  852  and apparatus  808  then functions as an OT control apparatus. 
     The signals provided from and to OI structure  100  or  400  via networks  814 ,  834 , and  836  or  848 ,  854 , and  856  in IP structures  800  and  830  or  840  and  850  may leave and enter OI structure  100  or  400  via wires along its sides or/and along substructure  134 . Any of those wires leaving structure  100  or  400  along its sides extend into adjoining material of FC region  108 , into other regions adjoining the sides of structure  100  or  400 , or/and into open space. Part of the signal processing performed on the signals provided from structure  100  or  400  via networks  814  and  834  or  848  and  854  to produce the signals provided to structure  100  or  400  via networks  836  or  856  may be physically performed in structure  100  or  400 , e.g., in FA layer  206  when VC region  106  is embodied as in any of OI structures  200 ,  270 , and  300  or  460 ,  480 , and  500 . Controllers  806  and  832  or  846  and  852  may thus partially merge into structure  100  or  400 . 
     Multiple Variable-Color Regions 
     “PP”, “AD”, “FR”, and “CP” hereafter respectively mean principal, additional, further, and composite. 
       FIGS. 78 a  and 78 b    (collectively “ FIG. 78 ”) illustrate the layout of an OI structure  880  for being impacted by object  104 . OI structure  880 , which serves as or in an IP structure, consists of PP OI structure  100  and an AD OI structure  882  that meet along a PP-AD interface  884 . See  FIG. 78 a   . Although interface  884  appears straight in  FIG. 78 a   , OI structures  100  and  882  can be variously geometrically configured, e.g., curved, or flat and curved, where they meet at interface  884 . They can meet at corners. PP structure  100  can extend partly or fully laterally around AD structure  882  and vice versa. For instance, structure  882  can adjoin structure  100  along two or more sides of structure  100  if it is shaped laterally like a polygon and vice versa. Structure  882  consists of an AD VC region  886  and a subordinate FC region  888  that meet along an AD region-region interface  890 . The preceding observations about the shape of interface  884  apply to interface  890  subject to color regions  886  and  888  replacing structures  100  and  882 . VC regions  106  and  886  meet along interface  884 . 
     AD VC region  886  extends to surface  102  at an AD VC SF zone  892  of surface  102  and normally appears along all of AD SF zone  892  as an AD SF color B. Region  886  is then in its normal state with only B light normally leaving it via zone  892 . AD SF color B differs, usually materially, from PP color A. Color B usually differs, usually materially, from changed color X. Region  886  contains AD ISCC structure along or below all of zone  892 . Examples of the AD ISCC structure, not separately indicated in  FIG. 78 , are described below and shown in later drawings. Region  886  may contain other structure likewise described below and shown in later drawings. 
     Subordinate FC region  888 , which extends to surface  102  at a subordinate FC SF zone  894 , fixedly appears along subordinate FC SF zone  894  as a subordinate SF color B′. Subordinate SF color B′, usually different from secondary color A′, is often the same as, but can differ significantly from, AD color B. Region  888  can consist of multiple subordinate FC subregions extending to zone  894  so that consecutive ones appear along it as different subordinate colors B′. Except as indicated below, region  888  is hereafter treated as appearing along zone  894  as only one color B′. SF zones  892  and  894  meet at an SF edge of interface  890 . 
     Color regions  106 ,  108 ,  886 , and  888  can laterally have various shapes besides the rectangles shown in  FIG. 78 . Examples of these shapes are presented below for  FIGS. 96-101 . FC regions  108  and  888  can meet each other. If so, they can merge so that colors A′ and B′ are the same color. 
     An ID portion, termed the AD IDVC portion, of VC region  886  responds to object  104  impacting VC SF zone  892  at an AD ID OC area  896  spanning where object  104  contacts (or contacted) zone  892  by temporarily appearing along a corresponding AD ID print area  898  of zone  892  as a generic altered SF color Y (a) in first general OI embodiments if the impact on AD ID OC area  896  meets AD basic TH impact criteria usually numerically the same as the PP basic TH impact criteria or (b) in second general OI embodiments if the AD IDVC portion is provided with an AD general CC control signal generated in response to the impact meeting the AD basic TH impact criteria sometimes dependent on other impact criteria also being met in those second embodiments. See  FIG. 78 b   . OC area  896  is capable of being of substantially arbitrary shape. AD ID print area  898  constitutes part of zone  892 , all of which is capable of temporarily appearing as generic altered SF color Y. Area  898  closely matches OC area  896  in size, shape, and location. Specifically, print area  898  at least partly encompasses OC area  896 , at least mostly, usually fully, outwardly conforms to it, and is largely concentric with it. The AD basic TH impact criteria can vary with where print area  898  occurs in zone  892 . 
     If VC region  886  includes structure besides the AD ISCC structure, an ID segment of the AD ISCC structure specifically responds to object  104  impacting OC area  896  by causing the AD IDVC portion to temporarily appear along print area  898  as altered SF color Y (a) in the first general OI embodiments if the impact on OC area  896  meets the AD basic TH impact criteria or (b) in the second general OI embodiments if the AD ID ISCC segment is provided with the AD general CC control signal. In any event, region  886  goes to its changed state with only Y light temporarily leaving the AD IDVC portion via print area  898 . Altered color Y differs materially from AD color B. Y light differs materially from B light. Altered color Y usually differs, usually materially, from PP color A. Color Y also usually differs from color B′ and may be the same as, or significantly differ from, changed color X. When object  104  impacts on or near PP-AD interface  884 , choosing colors X and Y to differ materially enables an observer to rapidly determine (if desired) whether object  104  only impacted SF zone  112 , only impacted SF zone  892 , or simultaneously impacted both of SF zones  112  and  892 . 
     Analogous to the PP basic TH impact criteria, the AD basic TH impact criteria can consist of multiple sets of fully different AD basic TH impact criteria respectively associated with multiple specific (or specified) altered colors materially different from AD color B. More than one, usually all, of the specific altered colors differ, usually materially, from one another. The impact of object  104  on SF zone  892  is potentially capable of meeting any of the AD basic TH impact criteria sets. If the impact on zone  892  meets the AD basic TH impact criteria, generic altered color Y is the specific altered color for the AD basic TH impact criteria set actually met by that impact likewise sometimes dependent on other criteria also being met. The AD basic TH impact criteria sets usually form a continuous chain in which consecutive criteria sets meet each other without overlapping. The AD basic TH impact criteria sets sometimes have the same mathematical description, presented above, as the PP basic TH impact criteria sets and can consist of fully different ranges of excess SF pressure across OC area  896  or excess internal pressure along a projection of area  896  onto an internal plane the same as described above for the PP basic TH impact criteria sets subject to recitations of AD, altered, color B, color Y, and area  896  respectively replacing the preceding recitations of principal, altered, color A, color X, and OC area  116 . 
       FIGS. 79 a  and 79 b    (collectively “ FIG. 79 ”) illustrate the layout of an OI structure  900  for being impacted by object  104 . OI structure  900 , which serves as or in an IP structure, consists of PP OI structure  100 , an FR OI structure  902 , and VC region  886  that meets OI structures  100  and  902  respectively along interface  884  and an AD-FR interface  904 . All the above observations about the shape of interface  884  apply to interface  904  subject to FR OI structure  902  replacing OI structure  882 . OI structure  902  consists of an FR VC region  906  and an ancillary FC region  908  that meet along an FR region-region interface  910 . See  FIG. 79 a   . All the above observations about the shape of interface  884  apply to interface  910  subject to color regions  906  and  908  replacing structures  100  and  882 . VC regions  886  and  906  meet along interface  904 . 
     FR VC region  906  extends to surface  102  at an FR VC SF zone  912  of surface  102  and normally appears along all of FR VC SF zone  912  as an FR SF color C. Region  906  is then its normal state with only C light normally leaving region  906  via zone  912 . FR SF color C differs, usually materially, from AD color B. Color C usually differs, usually materially, from altered color Y and changed color X. Region  906  can significantly differ structurally from, or be the same structurally as, PP VC region  106 . FR color C can thus significantly differ from, or be the same as, PP color A. PP color A, AD color B, and FR color C are sometimes termed normal-state colors. Region  906  contains FR ISCC structure along or below all of zone  912 . Examples of the FR ISCC structure, not separately indicated in  FIG. 79 , are described below and shown in later drawings. Region  906  may contain other structure likewise described below and shown in later drawings. 
     Ancillary FC region  908 , which extends to surface  102  at an ancillary FC SF zone  914 , fixedly appears along ancillary FC SF zone  914  as an ancillary SF color C′. Ancillary SF color C′, usually different from subordinate color B′, is often the same as, but can differ significantly from, FR color C. FC region  908  can significantly differ structurally from, or be the same structurally as, FC region  108 . Ancillary color C′ can thus significantly differ from, or be the same as, secondary color A′. Also, region  908  can consist of multiple ancillary FC subregions extending to zone  914  so that consecutive ones appear along zone  914  as different ancillary colors C′. Except as indicated below, region  908  is hereafter treated as appearing along zone  914  as only one color C′. Color SF zones  912  and  914  meet at an SF edge of interface  910 . 
     Color regions  108 ,  106 ,  886 ,  906 , and  908  can be laterally shaped differently than the rectangles shown in  FIG. 79 . See  FIGS. 96-101 . VC regions  106  and  906  can meet each other. If so, they can merge so that colors A and C are the same color. FC regions  108  and  908  can likewise meet each other. If so, regions  108  and  908  can similarly merge so that colors A′ and C′ are the same color. FC region  888  (not shown here) having FC SF zone  894  can adjoin VC region  886  where it does not adjoin VC region  106  or  906 . 
       FIG. 79 b    depicts an example in which object  104  impacts SF zone  892  of VC region  886  at OC area  896 . An ID portion, termed the FR IDVC portion, of VC region  906  responds to object  104  impacting SF zone  912  of region  886  at an FR ID OC area  916  spanning where object  104  contacts (or contacted) zone  912  by temporarily appearing along a corresponding FR ID print area  918  of zone  912  as a generic modified SF color Z (a) in first general OI embodiments if the impact on FR ID OC area  916  meets FR basic TH impact criteria usually numerically the same as the AD basic TH impact criteria and thus usually numerically the same as the PP basic TH impact criteria or (b) in second general OI embodiments if the FR IDVC portion is provided with an FR general CC control signal generated in response to the impact meeting the FR basic TH impact criteria sometimes dependent on other impact criteria also being met in those second embodiments. OC area  916  is capable of being of substantially arbitrary shape. FR ID print area  918  constitutes part of zone  912 , all of which is capable of temporarily appearing as generic modified SF color Z. Print area  918  closely matches OC area  916  in size, shape, and location. In particular, print area  918  at least partly encompasses OC area  916 , at least mostly, usually fully, outwardly conforms to it, and is largely concentric with it. The FR basic TH impact criteria can vary with where print area  918  occurs in zone  912 . 
     If VC region  906  includes structure besides the FR ISCC structure, an ID segment of the FR ISCC structure specifically responds to object  104  impacting OC area  916  by causing the FR IDVC portion to temporarily appear along print area  918  as modified SF color Z (a) in the first general OI embodiments if the impact on OC area  916  meets the FR basic TH impact criteria or (b) in the second general OI embodiments if the FR ID ISCC segment is provided with the FR general CC control signal. In any event, region  906  goes to its changed state with only Z light temporarily leaving the FR IDVC portion via print area  918 . OC area  916  is spaced apart from OC area  896  in  FIG. 79 b    and, along with print area  918 , is illustrated in dashed line in  FIG. 79 b    because spaced-apart occurrences of OC areas  896  and  916  are usually not simultaneously present. Modified color Z differs materially from FR color C. Z light thus differs materially from C light. Color Z usually differs, usually materially, from AD color B and PP color A. Color Z also usually differs from color C′ and may be the same as, or significantly differ from, color X or Y. When object  104  impacts on or near interface  904 , choosing colors Y and Z to differ materially enables an observer to rapidly determine (if desired) whether object  104  only impacted SF zone  892 , only impacted SF zone  912 , or simultaneously impacted both of SF zones  892  and  912 . Changed color X, altered color Y, and modified color Z are sometimes termed changed-state colors. 
     The FR basic TH impact criteria can consist of multiple sets of fully different FR basic TH impact criteria respectively associated with multiple specific (or specified) modified colors materially different from FR color B. More than one, usually all, of the specific modified colors differ, usually materially, from one another. The impact of object  104  on SF zone  912  is potentially capable of meeting any of the FR basic TH impact criteria sets. If the impact on zone  912  meets the FR basic TH impact criteria, generic modified color Z is the specific modified color for the FR basic TH impact criteria set actually met by that impact sometimes dependent on other criteria also being met. The FR basic TH impact criteria sets usually form a continuous chain in which consecutive criteria sets meet each other without overlapping. The FR basic TH impact criteria sets sometimes have the same mathematical description as the PP basic TH impact criteria sets and can consist of fully different ranges of excess SF pressure across OC area  916  or excess internal pressure along a projection of area  916  onto an internal plane the same as occurs with the PP basic TH impact criteria sets subject to recitations of FR, modified, color C, color Z, and OC area  916  respectively replacing the preceding recitation of principal, altered, color A, color X, and OC area  116 . 
     Recitations hereafter of (a) AD VC region  886  normally appearing as color B mean that it normally so appears along SF zone  892 , (b) the AD IDVC portion temporarily appearing as color Y mean that it temporarily so appears along print area  898 , (c) FR VC region  906  normally appearing as color C mean that it normally so appears along SF zone  912 , and (d) to the FR IDVC portion temporarily appearing as color Z mean that it temporarily so appears along print area  918 . Region  886  or  906  can be embodied and fabricated in any of the ways described above for embodying and fabricating VC region  106  subject to B or C light replacing A light. Region  886  or  906  also operates in any way above-described for operating region  106  subject to Y or Z light replacing X light and the AD or FR basic TH impact criteria replacing the PP basic TH impact criteria. The change from color B or C to color Y or Z along area  898  or  918  places region  886  or  906  in its changed state in which Y or Z light temporarily leaves the AD or FR IDVC portion via area  898  or  918 . 
     Object  104  can simultaneously impact both VC SF zone  892  and VC SF zone  112  or  912 . The AD IDVC portion can then temporarily appear as color Y if the AD basic TH impact criteria are met for the impact with OC area  896 , no print area being identified along zone  892  if the AD basic TH impact criteria are not so met. The PP or FR IDVC portion can similarly temporarily appear as color X or Z if the PP or FR basic TH impact criteria are met for the impact with OC area  116  or  916 , no print area being identified along zone  112  or  912  if the PP or FR basic TH impact criteria are not so met. The same can be done if object  104  simultaneously impacts all three zones  112 ,  892 , and  912 . However, this way of handling simultaneous impact of object  104  on zones  892  and  112  or/and  912  results in no print area being identified along zone  112 ,  892 , or  912  if the PP, AD, or FR basic TH impact criteria are not met even though the impact is of such a nature that the PP, AD, or FR basic TH impact criteria would be met if the impact had been fully in zone  112 ,  892 , or  912 . 
     Impact of object  104  simultaneously on both SF zone  892  and SF zone  112  or  912  or simultaneously on all of zones  112 ,  892 , and  912  is preferably handled by having the AD IDVC portion temporarily appear as color Y if the impact meets CP basic TH impact criteria for the total VC area where object  104  impacts zones  112 ,  892 , and  912 , i.e., for OC areas  896  and  116  or/and  916 . The PP IDVC portion ( 138 ) temporarily appears as color X if, besides impacting zone  892 , object  104  impacts zone  112 , and the FR IDVC portion temporarily appears as color Z if object  104  also impacts zone  912 . More specifically, the ID segments of the AD and PP or/and FR ISCC structures cause these temporary color changes. The CP basic TH impact criteria are usually numerically the same as the PP basic TH impact criteria and thus usually numerically the same as the AD or FR basic TH impact criteria. Regardless of how simultaneous impact on zones  892  and  112  or/and  912  is handled, CC durations Δt dr  for all IDVC portions going to the changed state are usually approximately the same. 
     The CP basic TH impact criteria can consist of multiple sets of fully different CP basic TH impact criteria respectively associated with multiple specific changed colors materially different from PP color A, multiple specific altered colors materially different from AD color B, and multiple modified colors materially different from FR color C. More than one, usually all, of the specific changed colors differ, usually materially, from one another. The same applies to the specific altered colors and to the specific modified colors. The impact of object  104  on SF zones  892  and  112  or/and  912  is potentially capable of meeting any of the CP basic TH impact criteria sets. If this impact meets the CP basic TH impact criteria, generic altered color Y is the specific altered color, generic changed color X is the specific changed color, or/and generic modified color Z is the specific modified color for the CP basic TH impact criteria set actually met by the impact. 
     The CP basic TH impact criteria sets usually form continuous chains in which consecutive PP criteria sets meet each other without overlapping. The same applies to consecutive AD criteria sets and to consecutive FR criteria sets. The CP basic TH impact criteria sets sometimes have a mathematical description consisting of a combination of the mathematical descriptions of the PP, AD, and FR basic TH impact criteria sets and can consist of fully different ranges of excess SF pressure across OC areas  116 ,  896 , and  916  or excess internal pressure along projections of areas  116 ,  896 , and  916  onto respective internal planes in the same way as occurs with the PP, AD, and FR basic TH impact criteria sets. 
       FIGS. 80 a , 80 b , 81 a , 81 b , 82 a , 82 b , 83 a , 83 b , 84 a , 84 b , 85 a   , and  85   b  present side cross sections of six embodiments of OI structure  900  where each pair of Figs. ja and jb for integer j varying from 80 to 85 depicts a different embodiment. The basic side cross sections, and thus how the embodiments appear in the normal state, are respectively shown in  FIGS. 80 a , 81 a , 82 a , 83 a , 84 a , and 85 a    corresponding to  FIG. 79 a   .  FIGS. 80 b , 81 b , 82 b , 83 b , 84 b , and 85 b    corresponding to  FIG. 79 b    present examples of changes that occur during the changed state when object  104  contacts surface  102  fully within AD VC SF zone  892 . 
       FIGS. 80 a  and 80 b    illustrate a general embodiment  920  of OI structure  900  in which VC regions  106 ,  886 , and  906  respectively consist only of PP ISCC structure  132 , the AD ISCC structure identified as item  922 , and the FR ISCC structure identified as item  924 . FC region  908 , AD ISCC structure  922 , and FR ISCC structure  924  meet substructure  134  along interface  136 . See  FIG. 80 a   . ISCC structures  922  and  924  also respectively extend up to SF zones  892  and  912 . Items  926  and  928  in  FIG. 80 b    respectively indicate the AD IDVC portion of region  886  and the AD ID segment of structure  922  present in AD IDVC portion  926 . AD ID ISCC segment  928  is identical to portion  926  here but is a part of portion  926  in later embodiments of OI structure  900  where region  886  contains structure besides ISCC structure  922 . 
     ISCC structures  922  and  924  usually operate the same as ISCC structure  132 . Referring to  FIG. 80 a   , light (if any) reflected by substructure  134  so as to leave it along AD VC region  886  during its normal state is termed BRsb light. Light, termed BDic light, normally leaving AD ISCC structure  922  via SF zone  892  after being reflected or/and emitted by structure  922 , and thus excluding any substructure-reflected BRsb light, consists of (a) light, termed BRic light, normally reflected by structure  922  so as to leave it via zone  892  after striking zone  892  and (b) light (if any), termed BEic light, normally emitted by structure  922  so as to leave it via zone  892 . Any BRsb light passes in substantial part through structure  922 . BRic light, any BEic light, and any BRsb light normally leaving structure  922 , and therefore region  886 , via zone  892  form B light. Region  886  normally appears as AD color B. 
     Light (if any) reflected by substructure  134  so as to leave it along FR VC region  906  during its normal state is termed CRsb light. Light, termed CDic light, normally leaving FR ISCC structure  924  via SF zone  912  after being reflected or/and emitted by structure  924 , and thus excluding any substructure-reflected CRsb light, consists of (a) light, termed CRic light, normally reflected by structure  924  so as to leave it via zone  912  after striking zone  912  and (b) light (if any), termed CEic light, normally emitted by structure  924  so as to leave it via zone  912 . Any CRsb light passes in substantial part through structure  924 . CRic light, any CEic light, and any CRsb light normally leaving structure  924 , and therefore region  906 , via zone  912  form C light. Region  906  normally appears as FR color C. 
     Referring to  FIG. 80 b   , light (if any) reflected by substructure  134  so as to leave it along AD IDVC portion  926  during the changed state for AD VC region  886  is termed YRsb light. Light, termed YDic light, temporarily leaving AD ID ISCC segment  928  via print area  898  during that changed state after being reflected or/and emitted by segment  928 , and thus excluding any substructure-reflected YRsb light, consists of (a) light, termed YRic light, temporarily reflected by segment  928  so as to leave it via area  898  after striking area  898  and (b) light (if any), termed YEic light, temporarily emitted by segment  928  so as to leave it via area  898 . YDic light differs materially from B and BDic light. Any YRsb light passes in substantial part through segment  928 . YRic light, any YEic light, and any YRsb light temporarily leaving segment  928 , and therefore portion  926 , via area  898  form Y light. Portion  926  temporarily appears as color Y. 
     Light (if any) reflected by substructure  134  so as to leave it along the FR IDVC portion during the changed state for FR VC region  906  is termed ZRsb light. Light, termed ZDic light, temporarily leaving an FR ID ISCC segment of FR ISCC structure  924  via print area  918  during that changed state after being reflected or/and emitted by the FR ISCC segment, and thus excluding any substructure-reflected ZRsb light, consists of (a) light, termed ZRic light, temporarily reflected by the FR ISCC segment so as to leave it via area  918  after striking area  918  and (b) light (if any), termed ZEic light, temporarily emitted by the FR ISCC segment so as to leave it via area  918 . ZDic light differs materially from Z and ZDic light. Any ZRsb light passes in substantial part through the FR ISCC segment. ZRic light, any ZEic light, and any ZRsb light temporarily leaving the FR ISCC segment, and therefore the FR IDVC portion, via area  918  form Z light. The FR IDVC portion temporarily appears as color Z. 
     BRsb and CRsb light reflected by substructure  134  respectively along VC regions  886  and  906  during the normal state each usually differ from ARsb light reflected by substructure  134  along VC region  106  during the normal state because the incident light traveling from SF zones  892  and  912  respectively through regions  886  and  906  to interface  136  usually differs from the incident light traveling from SF zone  112  through region  106  to interface  136 . Substructure-reflected BRsb and CRsb light usually differ from each other. YRsb or ZRsb light reflected by substructure  134  along AD IDVC portion  926  or the FR IDVC portion during the changed state can be the same as, or significantly different from, BRsb or CRsb light depending on how the light processing in portion  926  or the FR IDVC portion during the changed state differs from the light processing in region  886  or  906  during the normal state. YRsb or ZRsb light is absent when BRsb or CRsb light is absent. 
       FIGS. 81 a  and 81 b    illustrate an embodiment  930  of OI structure  920  in which VC regions  106 ,  886 , and  906  are again respectively formed solely with ISCC structures  132 ,  922 , and  924 . Region  886 , and thus structure  922 , consists of an AD IS component  932  and an AD CC component  934  which meet at an AD light-transmission interface  936 . See  FIG. 81 a   . AD components  932  and  934  are respectively arranged the same as PP components  182  and  184 . CC component  934  is formed with an AD electrode assembly  942 , an optional AD NA layer  944 , and an optional AD FA layer  946  respectively arranged the same as subcomponents  202 ,  204 , and  206 . Electrode assembly  942  consists of an AD core layer  952 , AD NE structure  954 , and AD FE structure  956  respectively arranged the same as subcomponents  222 ,  224 , and  226 . Light having at least a majority component of wavelength for color B normally leaves core layer  952  along NE structure  954  for enabling region  886  to normally appear as color B. 
     Referring to  FIG. 81 b   , each of components  932  and  934  has an AD ID segment present in IDVC portion  926 . The same applies to assembly  942 , NA layer  944  (when present), and FA layer  946  (when present) and to core layer  952 , NE structure  954 , and FE structure  956 . While these ID segments are not labeled in  FIG. 81 b    due to spacing limitations, each of them extends laterally fully across portion  926 . 
     ISCC structure  922  (or VC region  886 ) here operates the same as ISCC structure  132  (or VC region  106 ) in OI structure  200  subject to colors B and Y respectively replacing colors A and X and subject to the AD basic TH impact criteria replacing the PP basic TH impact criteria. The ID segment of IS component  932  responds to object  104  impacting OC area  896  so as to meet the AD basic TH impact criteria by providing an AD general impact effect as VC region  886  goes to the changed state. The ID segment of CC component  934  responds to the AD general impact effect, if provided, by causing IDVC portion  926  to temporarily appear along print area  918  as altered color Y. More specifically, region  886  responds to the AD general impact effect by providing the AD general CC control signal that is applied between a VA location in NE structure  954  and a VA location in FE structure  956 . At least one of the VA locations is in portion  926 , specifically in the ID segment of electrode structure  954  or  956 , and thus laterally depends on where object  104  contacts SF zone  892 . Core layer  952  responds to the AD general control signal by enabling light having at least a majority component of wavelength for color Y to temporarily leave the ID segment of layer  952  along the ID segment of NE structure  954  such that portion  926  temporarily appears as color Y. 
     ISCC structure  132  (or VC region  106 ) here is configured and operable the same as in OI structure  200 . The same applies to ISCC structure  924  (or VC region  906 ) subject to colors C and Z respectively replacing colors A and X and subject to the FR basic TH impact criteria replacing the PP basic TH impact criteria. Each ISCC structure  922  or  924  can be embodied and fabricated in any of the ways described above for embodying and fabricating ISCC structure  132 . 
       FIGS. 82 a  and 82 b    illustrate an extension  960  of OI structure  920 . OI structure  960  is configured the same as structure  920  except that VC regions  106 ,  886 , and  906  here respectively include SF structure  242 , an AD SF structure  962  extending from SF zone  892  to ISCC structure  922 , and an FR SF structure  964  extending from SF zone  912  to ISCC structure  924 . See  FIG. 82 a   . SF structures  962  and  964  respectively meet ISCC structures  922  and  924  along a flat AD structure-structure interface  966  and a flat FR structure-structure interface  968  coplanar with each other and with interface  244 . 
     Light travels through SF structures  962  and  964 . Each structure  962  or  964  functions the same, is internally configured the same, and has the same light transmissivity as SF structure  242 . VC region  106 ,  886 , or  906  here operates the same as region  106  in OI structure  240 . In particular, AD SF structure  962  typically protects ISCC structure  922  from damage and/or spreads pressure to improve the matching between print area  898  and OC area  896  during impact of object  104  on SF zone  892 . AD structure  962  may provide velocity restitution matching between zone  892  and FC SF zone  894  (not shown here), VC SF zone  112 , or/and VC SF zone  912 . With further reference to  FIG. 79 b   , FR SF structure  964  typically protects ISCC structure  924  from damage and/or spreads pressure to improve the matching between print area  918  and OC area  916  during impact on SF zone  912 . Structure  964  may provide velocity restitution matching between zone  912  and FC SF zone  914  or/and VC zone  892 . Also, structures  962  and  964  may respectively strongly influence colors B and C or/and colors Y and Z. Structures  242 ,  962 , and  964  usually merge seamlessly with one another to form a composite SF structure. 
     ISCC structure  922  or  924  here operates the same during the normal state as in OI structure  900  except that light leaving ISCC structure  922  or  924  via SF zone  892  or  912  in OI structure  900  leaves ISCC structure  922  or  924  via interface  966  or  968  here. The total light, termed BTic light, normally leaving structure  922  consists of BRic light reflected by it, any BEic light emitted by it, and any substructure-reflected BRsb light passing through it. The total light, termed CTic light, normally leaving structure  924  consists of CRic light reflected by it, any CEic light emitted by it, and any substructure-reflected CRsb light passing through it. 
     The BRic light, any BEic light, and any BRsb light pass in substantial part through SF structure  962 . Structure  962  may normally reflect light, termed BRss light, leaving it via SF zone  892  after striking zone  892 . BRis light, any BEic light, and any BRss and BRsb light normally leaving structure  962 , and thus VC region  886 , via zone  892  form B light. Similarly, the CRic light, any CEic light, and any CRsb light pass in substantial part through SF structure  964 . Structure  964  may normally reflect light, termed CRss light, leaving it via SF zone  912  after striking zone  912 . CRis light, any CEic light, and any CRss and CRsb light normally leaving structure  964 , and therefore VC region  906 , via zone  912  form C light. 
     SF structures  962  and  964  both usually absorb light. BTic or CTic light reaching SF zone  892  or  912  so as to leave VC region  886  or  906  can be of significantly lower radiosity than total BTic or CTic light directly leaving ISCC structure  922  or  924  along interface  966  or  968 . The observations made above about how wavelength dependency of light absorption by SF structure  242  affects ARic and AEic light apply to how wavelength dependency of light absorption by SF structure  962  or  964  affects BRic and BEic or CRic and CEic light subject to recitations of BRic or CRic light, BEic or CEic light, SF structure  962  or  964 , SF zone  892  or  912 , interface  966  or  968 , ISCC structure  922  or  924 , OI structure  920 , and OI structure  960  respectively replacing the preceding recitations of ARic light, AEic light, SF structure  242 , SF zone  112 , interface  244 , ISCC structure  132 , OI structure  130 , and OI structure  240 . 
     Referring to  FIG. 82 b   , item  970  indicates the AD ID area where impact of object  104  on AD SF zone  892  causes it to deform. Although AD ID SF DF area  970  is sometimes slightly smaller than OC area  896 , area  896  is also labeled as DF area  970  in  FIG. 82 b    and in later drawings to simplify the representation. Item  972  is the ID segment of SF structure  962  present in IDVC portion  926 . Item  974  is the ID segment of interface  966  present in portion  926  and is shown in  FIG. 82 b    and in analogous later side cross-sectional drawings with extra thick line to clearly identify its location along interface  966 . The excess SF pressure created by the impact is transmitted through structure  962  to interface  966  for producing excess internal pressure along an ID DP area  976  of interface  966 . Items  896 ,  898 ,  926 ,  928 ,  970 ,  972 ,  974 , and  976  respectively undergo the same actions as items  116 ,  118 ,  138 ,  142 ,  122 ,  252 ,  254 , and  256  in OI structure  240  subject to B and Y light respectively replacing A and X light so that portion  926  temporarily appears as color Y. 
     The changed state for AD VC region  886  begins as IDVC portion  926  changes to a condition in which YRic light reflected by ISCC segment  928  and any YEic light emitted by it temporarily leave it along ID IF segment  974 . The total light, termed YTic light, temporarily leaving ISCC segment  928  consists of YRic light, any YEic light, and any substructure-reflected YRsb light passing through it. The YRic light, any YEic light, and any YRsb light pass in substantial part through ID SS segment  972 . If SF structure  962  reflects BRss light during the normal state, segment  972  reflects BRss light during the changed state. YRic light, any YEic light, and any BRss and BRsb light temporarily leaving segment  972 , and thus portion  926 , via print area  898  form Y light. YDic light differs materially from B and BDic light. 
     The changed state for FR VC region  906  similarly begins as the FR IDVC portion changes to a condition in which ZRic light reflected by the FR ID ISCC segment and any ZEic light emitted by it temporarily leave it along an ID segment of interface  968 . The total light, termed ZTic light, temporarily leaving the FR ISCC segment consists of ZRic light, any ZEic light, and any substructure-reflected ZRsb light passing through it. The ZRic light, any ZEic light, and any ZRsb light pass in substantial part through an ID segment of FR SF structure  964 . If structure  964  reflects ZRss light during the normal state, the FR ID SS segment reflects ZRss light during the changed state. ZRic light, any ZEic light, and any CRss and ZRsb light temporarily leaving the FR SS segment, and thus the FR IDVC portion, via the FR print area ( 918 ) form Z light. ZDic light differs materially from C and CDic light. 
     Analogous to what occurs with XTic light, YTic light reaching print area  898  so as to leave IDVC portion  926  can be of significantly lower radiosity than total YTic light directly leaving ISCC segment  928  along IF segment  974 . With reference to  FIG. 79 b   , ZTic light reaching print area  918  so as to leave the FR IDVC portion can be of significantly lower radiosity than total ZTic light directly leaving the FR ID ISCC segment along the FR IF segment. The observations made above about how wavelength dependency of light absorption by SS segment  252  affects XRic and XEic light apply to how wavelength dependency of light absorption by SS segment  972  or the FR SS segment affects YRic and YEic or ZRic and ZEic light subject to recitations of YRic or ZRic light, YEic or ZEic light, print area  898  or  918 , ISCC segment  928  or the FR ISCC segment, IF segment  974  or the FR IF segment, SS segment  972  or the FR SS segment, SF structure  962  or  964 , OI structure  920 , OI structure  960 , and ISCC structure  922  or  924  respectively replacing the preceding recitations of XRic light, XEic light, print area  118 , ISCC segment  142 , IF segment  254 , SS segment  252 , SF structure  242 , OI structure  130 , OI structure  240 , and ISCC structure  132 . 
     SF structures  962  and  964  function as color filters for significantly absorbing light of selected wavelength in a preferred embodiment of OI structure  960  in which SF structure  962  strongly influences AD color B or/and altered color Y and in which SF structure  964  strongly influences FR color C or/and modified color Z. In this embodiment, total BTic light as it leaves ISCC structure  922  along interface  966  during the normal state for VC region  886  is of wavelength for a color termed AD internal color BTic. Total CTic light as it leaves ISCC structure  924  along interface  968  during the normal state for VC region  906  is of wavelength for a color termed FR internal color CTic. Total YTic light as it leaves ISCC segment  928  along IF segment  974  during the changed state for region  886  is of wavelength for a color termed altered internal color YTic. Total ZTic light as it leaves the FR ID ISCC segment along the FR IF segment during the changed state for region  906  is of wavelength for a color termed modified internal color ZTic. 
     A selected one of internal colors BTic and YTic for VC region  886  is an AD comparatively light color LA. The remaining one is an AD comparatively dark color DA darker than light color LA. Similarly, a selected one of internal colors CTic and ZTic for VC region  906  is an FR comparatively light color LF. The remaining one is an FR comparatively dark color DF darker than light color LF. Lightness L* of light color LA or LF is usually at least 70, preferably at least 80, more preferably at least 90. Lightness L* of dark color DA or DF is usually no more than 30, preferably no more than 20, more preferably no more than 10. 
     The following relationships arise between SF colors B and Y or C and Z due to light absorption by SF structure  962  or  964 . If AD internal color BTic for VC region  886  is light color LA, AD SF color B is darker than light color LA while changed SF color Y may be darker than dark color DA depending on the characteristics of the light absorption by structure  962  and on the lightness of color DA. Since color Y differs materially from color B, color Y is usually materially darker than color B. Similarly, if altered internal color YTic for region  886  is light color LA, altered SF color Y is darker than light color LA while AD SF color B may be darker than color DA. Color B is then usually materially darker than color Y. 
     If FR internal color CTic for VC region  906  is light color LF, FR SF color C is darker than light color LF due to the light absorption by SF structure  964  while modified SF color Z may be darker than dark color DF depending on the characteristics of the light absorption by structure  964  and on the lightness of color DF. Because color Z differs materially from color C, color Z is usually materially darker than color C. If modified internal color ZTic for region  906  is light color LF, modified SF color Z is darker than light color LF while FR SF color C may be darker than dark color DF. Color C is then usually materially darker than color Z. Structure  962  strongly influences AD color B or/and altered color Y while structure  964  strongly influences FR color C or/and modified color Z. 
     Importantly, ISCC structures  922  and  924  preferably have the same physical and chemical properties as ISCC structure  132  in this embodiment of OI structure  960 . ISCC structures  132 ,  922 , and  924  are preferably of the same internal construction, including dimensions perpendicular to substructure  134 , in this preferred OI embodiment so that the cost of developing at least two ISCC structures differing in physical properties, chemical properties, or/and internal construction is avoided. In fact, structures  132 ,  922 , and  924  here are preferably fabricated simultaneously as a single ISCC structure, thereby reducing the fabrication cost compared to the cost of fabricating at least two ISCC structures differing in physical properties, chemical properties, or/and internal construction. Internal colors BTic and CTic are thus identical to PP internal color ATic in this embodiment of OI structure  960 . Internal colors YTic and ZTic are identical to changed internal color XTic in this preferred OI embodiment. 
     The light absorption characteristics of SF structure  962  differ significantly from those of both of SF structures  242  and  964  in the preferred embodiment of OI structure  960 . The light absorption characteristics of structures  242 ,  962 , and  964  are chosen so that normal-state color B differs significantly from normal-state colors A and C. Color B is enabled to differ significantly from colors A and C by appropriately arranging for structure  962  to have significantly different light characteristics than structures  242  and  964  preferably formed, along with structure  962 , on a single ISCC structure which cooperates with structures  242 ,  962 , and  964  for enabling colors A, B, and C to respectively differ materially from changed-state colors X, Y, and Z. Because the development of multiple different ISCC structures is avoided, this OI embodiment is a highly efficient arrangement for achieving the invention&#39;s color-difference specifications. The colors embodying colors A, B, C, X, Y, and Z can be varied by changing the light absorption characteristics of structures  242 ,  962 , and  964  without modifying the ISCC structure. 
     Arranging for normal-state color B to differ significantly from normal-state colors A and C is facilitated by choosing internal color BTic to be light color LA. In that case, internal color ATic can be chosen to be light color LP or dark color DP while internal color CTic can be chosen to be light color LF or dark color DF. Choosing internal colors ATic and CTic to respectively be dark colors DA and DF provides color B with greater differences from colors A and C than does choosing colors ATic and CTic to respectively be light colors LP and LF but results in changed-state color Y differing more from changed-state colors X and Z. In any event, color B differs significantly from colors A and C when internal colors ATic and CTic are respectively chosen as light colors LP and LF by appropriately choosing the light absorption characteristics of SF structures  242 ,  962 , and  964 , especially taking advantage of the fact that colors A, B, and C are then respectively darker than light colors LP, LA, and LF. 
     Changed-state color Y may or may not differ significantly from changed-state colors X and Z depending on the light absorption characteristics of SF structures  242 ,  962 , and  964  and on which of colors LP, DP, LA, DA, LF, and DF are chosen for normal-state color A, B, and C and, by default, for colors X, Y, and Z. Arranging for colors X, Y, and Z to be close to one another, is facilitated for the preferred situation in which internal color BTic is light color LA by choosing internal colors ATic and CTic respectively to be light colors LP and LF so that internal colors XTic and ZTic respectively are dark colors DP and DF. Inasmuch as colors X, Y, and Z are then respectively darker than dark colors DP, DA, and DF, colors X, Y, and Z become closer to one another as dark colors DP, DA, and DF become progressively darker and become the same, namely black, when colors DP, DA, and DF become black. 
     In fabricating the preferred embodiment of OI structure  960 , the single ISCC structure implementing ISCC structures  132 ,  922 , and  924  is usually first provided on substructure  134 . SF structures  242 ,  962 , and  964  are then provided on the ISCC structure. Structures  242 ,  962 , and  964  can be prefabricated, e.g., as layers or strips, and then attached to the ISCC structure. Consecutive ones of the layers or strips are usually smooth and seamless where they meet along surface  102 . The layers or strips are also usually smooth and seamless where they meet FC regions along surface  102 . Alternatively, structures  242 ,  962 , and  964  can be deposited on the ISCC structure in fluid or semi-fluid form. The fluid can be a liquid or a gas. If the fluid is a liquid, the liquid or semi-liquid material of structures  242 ,  962 , and  964  is suitably dried. A semi-liquid form of the SS material can be a mixture, e.g., slurry, of solid particles and liquid such as water. 
       FIGS. 83 a  and 83 b    illustrate an embodiment  980  of OI structure  960 . OI structure  980  is also an extension of OI structure  930  to include SF structures  242 ,  962 , and  964  respectively in VC regions  106 ,  886 , and  906 . ISCC structure  132  here consists of components  182  and  184  configured and operable the same as in OI structure  260  and thus the same as in OI structure  180 . CC component  184  here preferably consists of subcomponents  204 ,  224 ,  222 ,  226 , and  206  (not shown) configured and operable the same as in OI structure  270  and therefore the same as in OI structure  200 . ISCC structure  922  here is formed with IS component  932  and CC component  934  consisting of subcomponents  944 ,  954 ,  952 ,  956 , and  946  configured and operable the same as in OI structure  930 . SF structure  962 , which again meets IS component  932  along interface  966 , is here configured the same as in OI structure  930 . ISCC structure  922  and SF structure  962  respectively operate the same as structures  132  and  242  in OI structure  270  subject to colors B and Y respectively replacing colors A and X and subject to the AD basic TH impact criteria replacing the PP basic TH impact criteria. 
     ISCC structure  924  consists of an FR IS component  982  and an FR CC component  984  that meet at an FR light-transmission interface  986 . FR components  982  and  984  are configured the same as PP components  182  and  184  in OI structure  260 , preferably as in OI structure  270 , and thus the same as components  182  and  184  in OI structure  180 , preferably as in OI structure  200 . ISCC structure  924  and SF structure  964  operate the same as structures  132  and  242  in OI structure  260 , preferably as in OI structure  270 , subject to colors C and Z respectively replacing colors A and X and subject to the FR basic TH impact criteria replacing the PP basic TH impact criteria. Each ISCC structure  922  or  924  can again be embodied and fabricated in any of the ways described above for embodying and fabricating ISCC structure  132 . SF structures  242 ,  962 , and  964  typically provide the above-described protection and matching functions. 
       FIGS. 84 a  and 84 b    illustrate an extension  990  of OI structure  960  for which the duration of each temporary color change along each print area  118 ,  898 , or  918  is extended in a pre-established deformation-controlled manner. OI structure  990  is configured the same as structure  960  except that VC regions  106 ,  886 , and  906  here respectively include DE structure  282  extending from substructure  134  to ISCC structure  132 , an AD DE structure  992  extending from substructure  134  to ISCC structure  922 , and an FR DE structure  994  extending from substructure  134  to ISCC structure  924 . See  FIG. 84 a   . DE structures  992  and  994  respectively meet ISCC structures  922  and  924  along a flat AD structure-structure interface  996  and a flat FR structure-structure interface  998  coplanar with each other and with interface  284 . SF structures  242 ,  962 , and  964  here typically provide the above-described protection and matching functions. 
     Each DE structure  992  or  994  is configured and operable the same as DE structure  282 . Referring to  FIG. 84 b    and to  FIGS. 18 b  and 79 b   , VC region  106 ,  886 , or  906  here operates in a deformation-based way utilizing DE structure  282 ,  992 , or  994  as described above for structure  282  in OI structure  320  to extend automatic value Δt drau  of duration Δt dr  of the changed state from color A, B, or C along print area  118 ,  898 , or  918  to color X, Y, or Z from base duration Δt drbs  to the sum of duration Δt drbs  and extension duration Δt drext  in response to object  104  impacting OC area  116 ,  896 , or  916 . 
     In particular, DE structure  992  responds to the deformation along ID DP area  976  of interface  966  resulting from the impact-caused deformation along SF DF area  970  by deforming along an AD ID internal DF area  1000  of interface  996 . Item  1002  is the ID segment of structure  992  present in IDVC portion  926 . Item  1004  is the ID segment of interface  996  present in portion  926 . Items  896 ,  898 ,  926 ,  928 ,  970 ,  972 ,  974 ,  976 ,  1000 ,  1002 , and  1004  respectively undergo the same actions as items  116 ,  118 ,  138 ,  142 ,  122 ,  252 ,  254 ,  256 ,  288 ,  292 , and  294  in OI structure  320  subject to B and Y light respectively replacing A and X light such that portion  926  temporarily appears as color Y. 
     SF structures  242 ,  962 , and  964  may be deleted in a variation of OI structure  990 . VC region  106 ,  886 , or  906  then operates in a deformation-based way utilizing DE structure  282 ,  992 , or  994  as described above for structure  282  in OI structure  280  to extend changed-state automatic duration Δt drau  from color A, B, or C along print area  118 ,  898 , or  918  to color X, Y, or Z from base duration Δt drbs  to Δt drbs +Δt drext  in response to object  104  impacting OC area  116 ,  896 , or  916 . 
       FIGS. 85 a  and 85 b    illustrate an extension  1010  of OI structure  980  for which the duration of each temporary color change along print area  118 ,  898 , or  918  is extended in a pre-established deformation-controlled manner. OI structure  1010  is configured the same as structure  980  except that VC regions  106 ,  886 , and  906  here respectively include DE structure  302  lying between components  182  and  184 , an AD DE structure  1012  lying between components  932  and  934 , and an FR DE structure  1014  lying between components  982  and  984 . See  FIG. 85 a   . AD DE structure  1012  meets components  932  and  934  respectively along flat near and far light-transmission interfaces  1016  and  1018  coplanar with interfaces  304  and  306 . FR DE structure  1014  meets components  982  and  984  respectively along flat near and far light-transmission interfaces  1026  and  1028  coplanar with interfaces  304  and  306 . SF structures  242 ,  962 , and  964  here again typically provide the above-described protection and matching functions. 
     Each DE structure  1012  or  1014  is configured and operable the same as DE structure  302 . CC component  184  here consists of subcomponents  204 ,  224 ,  222 ,  226 , and  206  configured the same as in OI structure  330  and thus the same as in OI structure  200 . Components  182  and  184  and structures  242  and  302  here operate the same as in OI structure  330 . CC component  934  here consists of subcomponents  944 ,  954 ,  952 ,  956 , and  946  configured the same as in OI structure  980 . Components  932  and  934  and structures  962  and  1012  respectively operate the same as components  182  and  184  and structures  242  and  302  in OI structure  330  subject to colors B and Y respectively replacing colors A and X and subject to the AD basic TH impact criteria replacing the PP basic TH impact criteria. 
     CC component  984  here is usually configured the same as CC component  184  in OI structure  330  and thus the same as component  184  in OI structure  200 . Components  982  and  984  and structures  964  and  1014  respectively operate the same as components  182  and  184  and structures  242  and  302  in OI structure  330  subject to colors C and Z respectively replacing colors A and X and subject to the FR basic TH impact criteria replacing the PP basic TH impact criteria. Referring to  FIG. 85 b    and to  FIGS. 19 b  and 79 b   , VC region  106 ,  886 , or  906  here operates in a deformation-based way utilizing DE structure  302 ,  1012 , or  1014  as described above for DE structure  302  in OI structure  330  to extend changed-state automatic duration Δt drau  from color A, B, or C along print area  118 ,  898 , or  918  to color X, Y, or Z from Δt drbs  to Δt drbs +Δt drext  in response to object  104  impacting OC area  116 ,  896 , or  916 . 
     Specifically, DE structure  1012  responds to the deformation along DP area  976  of interface  966  resulting from the impact-caused deformation along SF DF area  970  by deforming along an AD ID internal DF area  1030  of interface  1016 . Items  1032 ,  1034 ,  1036 , and  1038  are the ID segments of components  932  and  934 , structure  1012 , and interface  1016  respectively present in IDVC portion  926 . Items  896 ,  898 ,  926 ,  928 ,  970 ,  972 ,  1030 ,  1032 ,  1034 ,  1036 , and  1038  respectively undergo the same actions as items  116 ,  118 ,  138 ,  142 ,  122 ,  252 ,  308 ,  192 ,  194 ,  312 , and  314  in OI structure  330  subject to B and Y light respectively replacing A and X light such that portion  926  temporarily appears as color Y. 
     SF structures  242 ,  962 , and  964  may be deleted in a variation of OI structure  1010 . VC region  106 ,  886 , or  906  then operates in a deformation-based way utilizing DE structure  302 ,  1012 , or  1014  as described above for structure  302  in OI structure  300  to extend changed-state automatic duration Δt drau  from color A, B, or C along print area  118 ,  898 , or  918  to color X, Y, or Z from base duration Δt drbs  to Δt drbs +Δt drext  in response to object  104  impacting OC area  116 ,  896 , or  916 . 
       FIGS. 86 a  and 86 b    (collectively “ FIG. 86 ”) illustrate the layout of an OI structure  1080  for being impacted by object  104 . OI structure  1080 , which serves as or in an IP structure, consists of OI structure  400  and an AD OI structure  1082  which respectively embody OI structures  100  and  882  of larger OI structure  880 . VC region  886  of AD OI structure  1082  is allocated into a multiplicity of AD independently operable VC cells  1084 , usually identical, arranged laterally in a layer as a two-dimensional array. Each AD VC cell  1084  extends to a corresponding part  1086  of SF zone  892 . The dotted lines in  FIG. 86  indicate interfaces between SF parts  406  or  1086  of adjacent cells  404  or  1084 . The general layout of structure  1080  is shown in  FIG. 86 a   .  FIG. 86 b    depicts an example of color change that occurs along zone  892  upon being impacted by object  104  indicated in dashed line at a location subsequent to impact. 
     Cells  1084  are typically of the same shape and size as cells  404 , as occurs in the example of  FIG. 86 , but can be of different shape or/and size than cells  404 . Subject to colors B and Y respectively replacing colors A and X and subject to the PP cellular TH being replaced with AD cellular TH impact criteria usually numerically the same as the PP cellular TH impact criteria, cells  1084  can be configured, fabricated, programmed, and operated in any way described above for configuring, fabricating, programming, and operating cells  404 . This includes variously embodying cells  1084  with parts of IS component  932 , CC component  934 , SF structure  962 , and DE structure  992  or  1012  in any way that cells  404  are variously embodied with parts of components  182  and  184 , SF structure  242 , and DE structure  282  or  302 . 
       FIGS. 87 a  and 87 b    (collectively “ FIG. 87 ”) illustrate the layout of an OI structure  1100  for being impacted by object  104 . OI structure  1100 , which serves as or in an IP structure, consists of OI structure  400 , cellular VC region  886 , and an FR OI structure  1102  which respectively embody OI structure  100 , region  886 , and OI structure  902  of larger OI structure  900 . Hence, structure  1100  embodies structure  900 . VC region  906  of FR OI structure  1102  is allocated into a multiplicity of FR independently operable VC cells  1104 , usually identical, arranged laterally in a layer as a two-dimensional array. Each FR VC cell  1104  extends to a corresponding part  1106  of SF zone  912 . The dotted lines in  FIG. 87  indicate interfaces between SF parts  406 ,  1086 , or  1106  of adjacent cells  404 ,  1084 , or  1104 . The general layout of structure  1100  is shown in  FIG. 87 a   .  FIG. 87 b    depicts an example of color change that occurs along SF zone  892  upon being impacted by object  104  indicated in dashed line at a location subsequent to impact. 
     Cells  1104  are typically of the same shape and size as cells  404  and  1084 , as occurs in the example of  FIG. 87 , but can be of different shape or/and size than cells  404  and  1084 . SF parts  406 ,  1086 , and  1106  are shaped as regular hexagons in this example but can be shaped like other polygons, preferably quadrilaterals, more preferably rectangles, typically squares, or triangles, e.g., equilateral triangles. Interfaces  110 ,  884 ,  904 , and  910 , although crooked in  FIG. 87  due to the hexagonal cell shape, generally become straighter (or flatter) as cell SF parts  406 ,  1086 , and  1106  become smaller. Subject to colors C and Z respectively replacing colors A and X and subject to the PP cellular TH impact criteria being replaced with FR cellular TH impact criteria usually numerically the same as the PP cellular TH impact criteria, cells  1104  can be configured, fabricated, programmed, and operated in any way described above for configuring, fabricating, programming, and operating cells  404 . This includes variously embodying cells  1104  with parts of IS component  982 , CC component  984 , SF structure  964 , and DE structure  994  or  1014  in any way that cells  404  are variously embodied with parts of components  182  and  184 , SF structure  242 , and DE structure  282  or  302 . 
     Also, no changes in operation are needed if object  104  simultaneously impacts SF zones  892  and  112  or/and  912 . Each cell  404 ,  1084 , or  1104  meeting the PP, AD, or FR cellular TH impact criteria simply temporarily becomes a PP, AD, or FR CM cell. Recitations hereafter of (a) cells  1084  normally appearing as color B mean that they normally so appear along their parts  1086  of zone  892 , (b) an AD CM cell  1084  temporarily appearing as color Y means that it temporarily so appears along its part  1086  of print area  898 , (c) cells  1104  normally appearing as color C mean that they normally so appear along their parts  1106  of zone  912 , and (d) to an FR CM cell  1104  temporarily appearing as color Z means that it temporarily so appears along its part  1106  of print area  918 . 
     In manufacturing OI structure  1100 , cells  404 ,  1084 , and  1104  can be provided with programmable RA parts of any type described above and can be fabricated so as to be identical upon completion of manufacture. Cells  404 ,  1084 , and  1104  are then selectively programmed according to the programming technique appropriate to the type of RA parts incorporated into cells  404 ,  1084 , and  1104  so as to define the locations of interfaces  884  and  904  and any other interface between VC region  886  and another VC region such as VC region  106  or  906 . When structure  1100  is embodied using the cellular version of any of the mid-emission embodiments, cells  404 ,  1084 , and  1104  can alternatively or additionally be configured to have core subparts operable to emit radiosity-adjustable primary-color light as described above and can again be fabricated to be identical upon manufacture completion. Cells  404 ,  1084 , and  1104  in the mid-emission embodiments are then selectively programmed as described above to define the locations of interfaces  884  and  904  and any other interface between region  886  and another VC region. The boundaries of SF zone  892  along SF zones  112  and  912  and any other VC SF zones in surface  102  are thereby determined by the post-manufacture cell programming. 
     The cell programming can be partly or fully performed using the cell CC controller described below for  FIGS. 89, 92, and 93  with the programming voltages provided partly or fully along the COM paths for transmitting signals to OI structure  1100  depending on how cells  404 ,  1084 , and  1104  are made programmable and programmed. Separate cell-controller equipment (not shown) including separate COM paths (not shown) for partly or fully supplying the programming voltages may be used in the cell programming. 
     The forgoing programming explanation applies to OI structure  1080  subject to interface  904  not being present in structure  1080 . The boundary of SF zone  892  along SF zone  112  in surface  102  is thus determined by the post-manufacture cell programming. 
       FIG. 88  illustrates an IP structure  1110  consisting of (a) OI structure  900  formed with OI structure  100 , VC region  886 , and OI structure  902  and (b) a general CC controller  1114  responsive to instruction  608  for controlling duration Δt dr  of the changed state in response to suitable impact of object  104  on one or more of SF zones  112 ,  892 , and  912 . Networks  1116 ,  1118 , and  1120  of COM paths respectively extend from VC regions  106 ,  886 , and  906  to general CC controller  1114 . Networks  1122 ,  1124 , and  1126  of COM paths extend from controller  1114  respectively back to regions  106 ,  886 , and  906 . COM networks  1116 ,  1120 ,  1122 , and  1126  are shown in dashed line in  FIG. 88  because only COM networks  1118  and  1124  are used in the example of  FIG. 88  in which object  104  impacts zone  892 . 
     Controller  1114  may operate as a duration controller similar to controller  602  or as an intelligent controller similar to controller  702 . As a duration controller, controller  1114  responds to instruction  608  for adjusting CC duration Δt dr  after object  104  suitably impacts SF zone  112 ,  892 , or  912 . Also see  FIGS. 5 b , 54 b   , and  79   b . For impact on zone  112 , networks  1116  and  1122  respectively embody network  604  carrying the PP general LI impact signal if the PP basic TH impact criteria are met and network  606  carrying the PP general CC duration signal if instruction  608  is provided. The PP IDVC portion ( 138 ) temporarily appears as color X in accordance with instruction  608 . 
     For impact on SF zone  892  or  912 , the AD ID ISCC segment ( 928 ) or the FR ID ISCC segment provides an AD or FR general LI impact signal in response to the impact if it meets the AD or FR basic TH impact criteria. The AD or FR general LI impact signal, transmitted via network  1118  or  1120  to controller  1114 , identifies the actual or expected location of print area  898  or  918  along zone  892  or  912 . If instruction  608  is provided, controller  1114  responds to it and to the AD or FR general LI impact signal by providing an AD or FR general CC duration signal transmitted via network  1124  or  1126  to the AD or FR ISCC segment. The AD or FR ISCC segment responds by causing the AD IDVC portion ( 926 ) or the FR IDVC portion to temporarily appear as color Y or Z in accordance with instruction  608 . 
     Impact of object  104  simultaneously on both SF zone  892  and SF zone  112  or  912  or simultaneously on all of zones  112 ,  892 , and  912  is preferably handled by having the AD ID ISCC segment ( 928 ) provide the AD general LI impact signal if the impact meets the above-described CP basic TH impact criteria for the total VC area, i.e., OC areas  896  and  116  or/and  916 , where object  104  contacts zones  112  and  892  or/and  912 . The PP ID ISCC segment ( 142 ) then provides the PP general LI impact signal if object  104  impacts zone  112 , and the FR ID ISCC segment provides the FR general LI impact signal if object  104  impacts zone  912 . 
     As an intelligent controller, controller  1114  provides a supplemental impact assessment capability for determining whether an impact of object  104  on SF zone  112 ,  892 , or  912  meeting the PP, AD, or FR basic TH impact criteria has certain supplemental impact characteristics and, if so, for causing the IDVC portion in VC region  106 ,  886 , or  906  to temporarily appear as color X, Y, or Z. Also see  FIGS. 5 b , 64 b , and 79 b   . Also, controller  1114  here responds to instruction  608  for adjusting CC duration Δt dr  in the preceding way. For impact on zone  112 , networks  1116  and  1122  respectively embody network  704  carrying the PP general CI impact signal provided by the PP ID ISCC segment ( 142 ) if the PP basic TH impact criteria are met and network  706  carrying the PP general CC initiation signal, here provided by controller  1114 , for causing the PP IDVC portion ( 138 ) to temporarily appear as color X if the PP general supplemental impact information provided by the PP general CI impact signal meet the PP supplemental impact criteria. Network  1122  also embodies network  606  carrying the PP general CC duration signal if instruction  608  is provided. 
     For impact on SF zone  892  or  912 , the AD ID ISCC segment ( 928 ) or the FR ID ISCC segment provides an AD or FR general CI impact signal in response to object  104  impacting zone  892  or  912  if the AD or FR basic TH impact criteria are met. The AD or FR general CI impact signal, transmitted via network  1118  or  1120  to controller  1114 , identifies certain AD or FR characteristics of that impact. The AD or FR impact characteristics consist of the location expected for print area  898  or  918  in zone  892  or  912  and AD or FR general supplemental impact information usually formed with the same parameters, e.g., PA size and/or shape, as the PP general supplemental impact information. 
     Controller  1114  responds by determining whether the AD or FR general supplemental impact information meet AD or FR supplemental impact criteria usually numerically the same as the PP supplemental impact criteria and, if so, provides an AD or FR general CC initiation signal, transmitted via network  1124  or  1126  to the AD ID ISCC segment ( 928 ) or the FR ID ISCC segment, for causing the AD IDVC portion ( 926 ) or the FR IDVC portion to temporarily appear as color Y or Z. An impact on SF zone  892  or  912  must meet AD or FR expanded impact criteria consisting of the AD or FR basic TH impact criteria and the AD or FR supplemental impact criteria to cause a temporary color change. IP structure  1110  thus provides color change for suitable impacts of object  104  for which color changes is desired and substantially avoids providing color change for impacts of bodies for which color change is not desired. If controller  1114  receives instruction  608  and if the AD or FR supplemental impact criteria are met, controller  1114  responds by providing the AD or FR general CC duration signal, transmitted via network  1124  or  1126  to the AD or FR ISCC segment, for adjusting CC duration Δt dr  subsequent to impact. 
     Similar to the PP supplemental impact criteria, the AD or FR supplemental impact criteria can consist of multiple sets of fully different AD or FR supplemental impact criteria respectively associated with different specific altered or modified colors materially different from AD color B or FR color C. More than one, usually all, of the specific altered or modified colors again differ, usually materially, from one another. The AD or FR supplemental impact information is potentially capable of meeting any of the AD or FR supplemental impact criteria sets. If the AD or FR supplemental impact information meets the AD or FR supplemental impact criteria, generic altered color Y or generic modified color Z is the specific altered or modified color for the AD or FR supplemental impact criteria set actually met by the AD or FR supplemental impact information. Controller  1114  usually provides the AD or FR general CC initiation signal for causing the AD IDVC portion ( 926 ) or the FR IDVC portion to temporarily appear as specific altered color Y or specific modified color Z for the AD or FR supplemental impact criteria set met by the AD or FR supplemental impact information the same as controller  702  provides the PP general CC initiation signal for causing the PP IDVC portion ( 138 ) to temporarily appear as the specific changed color X for the PP supplemental impact criteria set met by the PP supplemental impact information. 
     Impact of object  104  simultaneously on SF zones  892  and  112  or/and  912  is preferably handled by having the AD ID ISCC segment ( 928 ) provide the AD general CI impact signal if the impact meets the CP basic TH impact criteria for the total VC area where object  104  contacts zones  112  and  892  or/and  912 . The PP ID ISCC segment ( 142 ) then provides the PP general CI impact signal if, besides impacting zone  892 , object  104  impacts zone  112 , and the FR ID ISCC segment provides the FR general CI impact signal if object  104  also impacts zone  912 . Controller  1114  responds to the two or three general CI impact signals by combining the AD and PP or/and FR general supplemental impact information to form CP general supplemental impact information and determining whether it meets CP supplemental impact criteria usually numerically the same as the AD supplemental impact criteria and therefore usually numerically the same as the PP and FR supplemental impact criteria. If so, controller  1114  provides the AD general CC initiation signal for causing the AD IDVC portion ( 926 ) to temporarily appear as color Y. Controller  1114  provides the PP general CC initiation signal for causing the PP IDVC portion ( 138 ) to temporarily appear as color X if object  104  also impacted SF zone  112  or/and the FR general CC initiation signal for causing the FR IDVC portion to temporarily appear as color Z if object  104  also impacted zone  912 . An impact on zones  892  and  112  or/and  912  must thus meet CP expanded impact criteria consisting of the CP basic TH impact criteria and the CP supplemental impact criteria, which apply to the total VC area where object  104  contacts zones  112  and  892  or/and  912 , to cause a temporary color change. 
     The CP supplemental impact criteria can consist of multiple sets of fully different CP supplemental impact criteria respectively associated with multiple specific altered colors materially different from AD color B and multiple specific changed colors materially different from PP color A or/and multiple modified colors materially different from FR color C. More than one, usually all, of the specific changed, altered, or modified colors differ, usually materially. The impact of object  104  on SF zones  892  and  112  or/and  912  is potentially capable of meeting any of the CP supplemental impact criteria sets. If the impact meets the CP supplemental impact criteria, generic modified color Y is the specific altered color and generic changed color X is the specific changed color or/and generic modified color Z is the specific modified color for the CP supplemental impact criteria set actually met by the impact. 
       FIG. 89  illustrates an IP structure  1130  consisting of (a) OI structure  1100  formed with OI structure  400 , cellular VC region  886 , and OI structure  1102  and (b) a cell CC controller  1134  responsive to instruction  608  for controlling duration Δt dr  of the changed state in response to suitable impact of object  104  on one or more of SF zones  112 ,  892 , and  912 . SF parts  406 ,  1086 , and  1106  of cells  404 ,  1084 , and  1104  are shown here as being rectangles, specifically squares. Networks  1136 ,  1138 , and  1140  of COM paths respectively extend from VC regions  106 ,  886 , and  906  to cell CC controller  1134 . Networks  1142 ,  1144 , and  1146  of COM paths extend from controller  1134  respectively back to regions  106 ,  886 , and  906 . Each COM network  1136 ,  1138 ,  1140 ,  1142 ,  1144 , or  1146  usually includes a set of row COM paths, each connected to a different row of cells  404 ,  1084 , or  1104 , and a set of column COM paths, each connected to a different column of cells  404 ,  1084 , or  1104 . Networks  1136 ,  1140 ,  1142 , and  1146  and parts of networks  1138  and  1144  are shown in dashed line in  FIG. 89  because only the remaining parts of networks  1138  and  1144  are used in the example of  FIG. 89  in which object  104  impacts zone  892 . 
     Controller  1134  may operate as a duration controller similar to controller  652  or as an intelligent controller similar to controller  752 . As a duration controller, controller  1134  responds to instruction  608  for adjusting CC duration Δt dr  after object  104  suitably impacts SF zone  112 ,  892 , or  912 . Also see  FIGS. 38 b , 59 b , 79 b , and 87 b   . For impact on zone  112 , networks  1136  and  1142  respectively embody network  654  carrying the PP cellular LI impact signals from CM cells  404  and network  656  carrying the PP cellular CC duration signals to CM cells  404  if instruction  608  is provided. After each CM cell  404  starts to temporarily appear as color X, each CM cell  404  continues to appear as color X in accordance with instruction  608 . 
     For impact on SF zone  892  or  912 , each cell  1084  or  1104  meeting the AD or FR cellular TH impact criteria in response to the impact temporarily becomes a CM cell. The ISCC part of each CM cell  1084  or  1104  provides an AD or FR cellular LI impact signal, transmitted via network  1138  or  1140  to controller  1134 , identifying that cell&#39;s location along zone  892  or  912 . If controller  1134  receives instruction  608 , controller  1134  responds to it and to the cellular LI impact signal of each CM cell  1084  or  1104  by providing an AD or FR cellular CC duration signal, transmitted via network  1144  or  1146  to that cell&#39;s ISCC part, for adjusting that cell&#39;s CC duration Δt dr  subsequent to impact. After each CM cell  1084  or  1104  starts to temporarily appear as color Y or Z, the ISCC part of each CM cell  1084  or  1104  responds to its cellular CC duration signal by causing it to continue appearing as color Y or Z in accordance with instruction  608 . 
     As an intelligent controller, controller  1134  provides a supplemental impact assessment capability for determining whether an impact of object  104  on SF zone  112 ,  892 , or  912  meeting the PP, AD, or FR cellular TH impact criteria has certain supplemental impact characteristics and, if so, for causing CM cells  404 ,  1084 , or  1104  to temporarily appear as color X, Y, or Z. Also see  FIGS. 38 b , 69 b , 79 b , and 87 b   . Additionally, controller  1134  here responds to instruction  608  for adjusting CC duration Δt dr  in the preceding way. For impact on zone  112 , networks  1136  and  1142  respectively embody network  754  carrying the PP cellular CI impact signal for any cell  404  meeting the PP cellular TH impact criteria so as to be a TH CM cell and network  756  carrying the PP cellular CC initiation signal, provided here by controller  1134 , for causing each TH CM cell  404  to temporarily become a full CM cell and temporarily appear as color X if the PP general supplemental impact information provided by the PP cellular CI impact signals of TH CM cells  404  meet the PP supplemental impact criteria. Network  1142  embodies network  656  carrying the PP cellular CC duration signals for all full CM cells  404  if instruction  608  is provided. 
     For impact on SF zone  892  or  912 , the ISCC part of each cell  1084  or  1104  meeting the AD or FR cellular TH impact criteria responds to object  104  impacting OC area  896  or  916  by providing an AD or FR cellular CI impact signal, transmitted via network  1138  or  1140  to controller  1134 , identifying certain cellular characteristics of the impact as experienced at that cell  1084  or  1104 . Each such cell  1084  or  1104  temporarily becomes a TH CM cell. The cellular impact characteristics for each TH CM cell  1084  or  1104  consist of the location of its SF part  1086  or  1106  in zone  892  or  912  and AD or FR cellular supplemental impact information. 
     Controller  1134  responds to the AD or FR cellular CI impact signals by combining the AD or FR cellular supplemental impact information of TH CM cells  1084  or  1104  to form the AD or FR general supplemental impact information and determines whether it meets the AD or FR supplemental impact criteria. If so, each TH CM cell  1084  or  1104  temporarily becomes a full CM cell. For each full CM cell  1084  or  1104 , controller  1134  provides an AD or FR cellular CC initiation signal transmitted via network  1144  or  1146  to that cell&#39;s ISCC part. Each full CM cell  1084  or  1104  then temporarily appears as color Y or Z. The AD or FR expanded impact criteria that must be met to cause a temporary color change consist of the AD or FR cellular TH impact criteria and the AD or FR supplemental impact criteria. Color change occurs for suitable impacts of object  104  for which color changes is desired and substantially avoids occurring for impacts of bodies for which color change is not desired. If controller  1134  receives instruction  608  and if the AD or FR supplemental impact criteria are met, controller  1134  responds by providing the AD or FR cellular CC duration signal, transmitted via network  1144  or  1146 , to the ISCC part of each full CM cell  1084  or  1104  for adjusting its CC duration Δt dr  subsequent to impact. Controller  1134  usually creates the PP, AD, or/and FR cellular CC initiation signals by producing a general CC initiation signal and suitably splitting it. 
     Simultaneous impact of object  104  on SF zones  892  and  112  or/and  912  is handled in the preceding way except that controller  1134  responds to the AD and PP or/and FR cellular CI impact signals by combining the cellular supplemental impact information of TH CM cells  1084  and  404  or/and  1104  to form CP general supplemental impact information and determines whether it meets the above-mentioned CP supplemental impact criteria. If so, each of TH CM cells  1084  and  404  or/and  1104  temporarily becomes a full CM cell. Controller  1134  provides the AD CC initiation signal for each full CM cell  1084  and the PP cellular CC initiation signal for each full CM cell  404  or/and the FR cellular CC initiation signal for each full CM cell  1104 . Each full CM cell  1084  temporarily appears as color Y and each full CM cell  404  temporarily appears as color X or/and each full CM cell  1104  temporarily appears as color Z. The CP expanded impact criteria which must be met to cause a temporary color change consist of the CP supplemental impact criteria combined with the AD and PP or/and FR cellular TH impact criteria. 
       FIG. 90  illustrates an IP structure  1150  consisting of OI structure  900  and an IG system  1152  for variously generating images of print areas  118 ,  898 , and  918  and selected adjoining SF area. Also see  FIGS. 5 b  and 79 b   . Persons can utilize the images to examine where area  118 ,  898 , or  918  occurs in SF zone  112 ,  892 , or  912 , e.g., to determine how closely area  118 ,  898 , or  918  comes to a selected part of the boundary of zone  112 ,  892 , or  912 . 
     IG system  1152  consists of IG structure  804  for generating images and a general IG controller  1154  for controlling structure  804  to suitably generate PP, AD, FR, and CP PAV images. Image-collecting apparatus  808  in structure  804  is deployed for collecting an image of any part of VC SF zone  112 ,  892 , or  912  and usually an adjoining part of surface  102  outside zone  112 ,  892 , or  912 . Networks  1156 ,  1158 , and  1160  of COM paths respectively extend from VC regions  106 ,  886 , and  906  to general IG controller  1154 . COM networks  1156  and  1160  are shown in dashed line in  FIG. 90  because only COM network  1158  is used in this example in which object  104  impacts zone  892 . 
     Each PP, AD, or FR PAV image consists of an image of print area  118 ,  898 , or  918  and adjacent surface extending to at least a selected location of surface  102 . The selected SF location is usually a partial boundary of SF zone  112 ,  892 , or  912 , e.g., the edge of one of interfaces  110  and  884  along zone  112 , the edge of one of interfaces  884  and  904  along zone  892 , or the edge of one of interfaces  904  and  910  along zone  912 . Each CP PAV image, generated for impact simultaneously on zones  892  and  112  or/and  912 , consists of an image of areas  898  and  118  or/and  918  along with adjacent surface of surface  102 . Subject to area  898  or  918  replacing area  118 , each AD or FR PAV image has the above-described characteristics of a PP PAV image. The same applies to each CP PAV image subject to areas  898  and  118  or/and  918  replacing area  118 . 
     The ID ISCC segment of VC region  106 ,  886 , or  906  again provides a PP, AD, or FR general LI impact signal in response to object  104  impacting OC area  116 ,  896 , or  916  if the PP, AD, or FR basic TH impact criteria are met. IG controller  1154  and IG structure  804  operate the same as IG controller  806  and structure  804  in responding to the PP general LI impact signal transmitted via network  1156 , largely network  814 , to controller  1154 . Hence, controller  1154  can usually be set to operate in either the automatic or instruction mode of controller  806  for providing the PP PA identification signal transmitted via path  816  to structure  804  for causing it to generate a PP PAV image if a PP IG condition is met. Responsive to the AD or FR general LI impact signal transmitted via network  1158  or  1160 , controller  1154  operating in either the automatic or instruction mode similarly provides an AD or FR PA identification signal identifying the location of print area  898  or  918  in SF zone  892  or  912  provided that an AD or FR IG condition is met. Structure  804  responds to the AD or FR PA identification signal transmitted via path  816  by generating an AD or FR PAV image the same as structure  804  generates a PP PAV image. The PP, AD, or FR IG condition consists of print area  118 ,  898 , or  918  meeting the PP, AD, or FR distance condition that a point in area  118 ,  898 , or  918  be less than or equal to a selected distance away from a selected location on surface  102  or controller  1154  receiving instruction  822 . 
     Impact simultaneously on SF zones  892  and  112  or/and  912  is handled in the preceding way except that the AD ID ISCC segment ( 928 ) provides the AD general LI impact signal in response to object  104  impacting OC area  896  if the impact meets the CP basic TH impact criteria for the total VC area where object  104  contacts zones  892  and  112  or/and  912 . The PP ID ISCC segment ( 142 ) provides the PP general LI impact signal if, besides impacting zone  892 , object  104  impacts zone  112 , and the FR ID ISCC segment provides the FR general LI impact signal if object  104  also impacts zone  912 . Responsive to the AD and PP or/and FR general LI impact signals, controller  1154  again operating in either the automatic or instruction mode provides a CP PA identification signal identifying the location of print areas  898  and  118  or/and  918  in zones  892  and  112  or/and  912  provided that a CP IG condition is met. The CP IG condition consists of areas  898  and  118  or/and  918  meeting the distance condition that a point in areas  898  and  118  or/and  918  be less than or equal to a selected distance away from a selected location on surface  102  or controller  1154  receiving instruction  822 . For the automatic mode, the distance condition is often satisfied when area  898  adjoins area  118  or/and area  918  as indicated by controller  1154  receiving the AD and PP or/and FR general LI impact signals. IG structure  804  responds to the CP PA identification signal transmitted via path  816  by generating a CP PAV image the same as structure  804  generates a PP PAV image. 
     Controller  1154  may maintain an electronic map of SF zones  112 ,  892 , and  912 , including the locations of the edges of interfaces  110 ,  884 ,  904 , and  910  along surface  102  and each other part of the boundaries of zones  112 ,  892 , and  912 . Responsive to the PP, AD, or FR general LI impact signal, controller  1154  determines the expected location of print area  118 ,  898 , or  918  on the map and generates the data for a PP, AD, or FR PAV image if the PP, AD, or FR IG condition is met. The PP, AD, or FR PAV-image data includes the shape of the perimeter of area  118 ,  898 , or  918 , the shape of the selected location on surface  102 , and distance data defining the lateral spatial relationship between the perimeter of area  118 ,  898 , or  918  and the selected SF location. 
     If object  104  simultaneously impacts SF zones  892  and  112  or/and  912  so as to meet the CP basic TH impact criteria, controller  1154  responds to the AD and PP or/and FR general LI impact signals by determining the expected locations of print areas  898  and  118  or/and  918  on the electronic map and generates the data for a CP PAV image if the CP IG condition is met. The CP PAV-image data includes the shape of the composite perimeter of areas  898  and  118  or/and  918 , the shape of the selected location on surface  102 , and distance data defining the lateral spatial relationship between the composite perimeter of areas  898  and  118  or/and  918  and the selected SF location. Controller  1154  provides the PP, AD, FR, or CP PAV-image data directly, e.g., via path  820 , to screen  810  which responds by generating the PP, AD, FR, or CP PAV image. 
       FIG. 91  illustrates an IP structure  1170  consisting of OI structure  900 , CC controller  1114 , and IG system  1152  formed with IG structure  804  and IG controller  1154 . Also see  FIGS. 5 b , 79 b   , and  88 . Networks  1156 ,  1158 , and  1160  extending from VC regions  106 ,  886 , and  906  to controller  1154  may respectively partly overlap networks  1116 ,  1118 , and  1120  respectively extending from regions  106 ,  886 , and  906  to CC controller  1114 . Networks  1122 ,  1124 , and  1126  again extend from CC controller  1114  respectively back to regions  106 ,  886 , and  906 . OI structure  900  and controller  1114  here operate the same as in IP structure  1110 . OI structure  900 , IG structure  804 , and IG controller  1154  here operate the same as in IP structure  1150  except as described below. 
     CC controller  1114  can again be a duration controller, similar to controller  602 , for adjusting CC duration Δt dr  subsequent to impact. Alternatively, controller  1114  can be intelligent controller, similar to controller  702 , for providing the supplemental impact assessment capability to determine whether an impact meeting the PP, AD, or FR basic TH impact criteria has certain supplemental impact characteristics and, if so, for causing the IDVC portion in VC region  106 ,  886 , or  906  to temporarily appear as color X, Y, or Z. 
     IG controller  1154  can operate in various ways when controller  1114  is an intelligent controller. If a PAV image is desired regardless of whether the PP, AD, or FR supplemental impact criteria are, or are not, met, controller  1154  supplies the PP, AD, or FR PA identification signal in response to the location expected for print area  118 ,  898 , or  918  provided in the PP, AD, or FR general CI impact signal transmitted via network  1156 ,  1158 , or  1160 . A PP, AD, or FR PAV image is generated whenever the PP, AD, or FR basic TH impact criteria are met. Controller  1154  preferably provides the PP, AD, or FR PA identification signal in response to the PP, AD, or FR general CC initiation signal supplied from controller  1114  via a COM path  1172 . In that case, a PAV image is generated only when the PP, AD, or FR supplemental impact criteria are met. Impact simultaneously on SF zones  892  and  112  or/and  912  for both ways of operating controller  1154  is handled the same as just described except that the processing of the PA-location identifying information in the AD and PP or/and FR general CI impact signals is modified as described above in regard to IP structure  1150  for processing the AD and PP or/and FR general LI impact signals for impact simultaneously on zones  892  and  112  or/and  912 . 
       FIG. 92  illustrates an IP structure  1180  consisting of OI structure  1100  and an IG system  1182  for generating images of print areas  118 ,  898 , and  918  and selected adjoining SF area. Also see  FIGS. 38 b , 79 b , 87 b   , and  89 . SF parts  406 ,  1086 , and  1106  of cells  404 ,  1084 , and  1104  again appear as rectangles, specifically squares. Persons can again utilize the images to examine where area  118 ,  898 , or  918  occurs in SF zone  112 ,  892 , or  912 , e.g., to determine how closely area  118 ,  898 , or  918  comes to a selected part of the boundary of zone  112 ,  892 , or  912 . 
     IG system  1182  consists of IG structure  804  for generating images and a cell IG controller  1184  for controlling structure  804  to suitably generate PP, AD, FR, and CP PAV images having the above-described characteristics. Image-collecting apparatus  808  in structure  804  is again used for collecting an image of any part of SF zone  112 ,  892 , or  912  and usually an adjoining part of surface  102  outside zones  112 ,  892 , and  912 . Networks  1186 ,  1188 , and  1190  of COM paths respectively extend from VC regions  106 ,  886 , and  906  to cell IG controller  1184 . Each COM network  1186 ,  1188 , or  1190  usually includes a set of row COM paths, each connected to a different row of cells  404 ,  1084 , or  1104 , and a set of column COM paths, each connected to a different column of cells  404 ,  1084 , or  1104 . Networks  1186  and  1190  and part of network  1188  are shown in dashed line in  FIG. 92  because only the remainder of network  1188  is used in this example in which object  104  impacts zone  892 . 
     The ISCC part of each CM cell  404 ,  1084 , or  1104  again provides a PP, AD, or FR cellular LI impact signal in response to object  104  impacting OC area  116 ,  896 , or  916 . IG controller  1184  and IG structure  804  operate the same as IG controller  846  and structure  804  in responding to the PP cellular LI impact signals transmitted from CM cells  404  via network  1186 , largely network  848 , to controller  1184 . Controller  1184  can usually be set to operate in either the automatic or instruction mode of controller  846 , and thus of controller  806 , for providing the PP PA identification signal transmitted via path  816  to structure  804  for causing it to generate a PP PAV image. Responsive to the AD or FR general LI impact signal transmitted via network  1188  or  1190 , controller  1184  operating in either the automatic or instruction mode similarly provides an AD or FR PA identification signal identifying the location of print area  898  or  918  in SF zone  892  or  912  provided that an AD or FR IG condition is met. Structure  804  again responds to the AD or FR PA identification signal transmitted via path  816  by generating an AD or FR PAV image the same as structure  804  generates a PP PAV image. The PP, AD, or FR IG condition consists of print area  118 ,  898 , or  918  meeting the above-described PP, AD, or FR distance condition or controller  1184  receiving instruction  822 . 
     If object  104  simultaneously impacts SF zones  892  and  112  or/and  912 , the ISCC part of each cell  404 ,  1084 , or  1104  meeting the PP, AD, or FR cellular TH impact criteria provides a PP, AD, or FR cellular LI impact signal in response to the impact and temporarily becomes a CM cell. Responsive to the AD and PP or/and FR cellular LI impact signals, controller  1184  provides a CP PA identification signal identifying the location of print areas  898  and  118  or/and  918  in zones  892  and  112  or/and  912  provided that the above-described CP IG condition is met. IG structure  804  again responds to the CP PA identification signal transmitted via path  816  by generating a CP PAV image the same as structure  804  generates a PP PAV image. 
     An electronic map of SF zones  112 ,  892 , and  912 , including the locations of the SF edges of interfaces  110 ,  884 ,  904 , and  910  and each other part of the boundaries of zones  112 ,  892 , and  912 , may be maintained in controller  1184 . If so, controller  1184  can generate the data for a PP, AD, FR, or CP PAV image the same as controller  1154  uses such a map to generate the data for a PP, AD, FR, or CP PAV image. The PP, AD, FR, or CP PAV-image data is then supplied from controller  1184  directly, e.g., via path  820 , to screen  810  which displays the PP, AD, FR, or CP PAV image. The cell arrangement of VC regions  106 ,  886 , and  906  in OI structure  1100  facilitates generation of the map because SF part  406 ,  1086 , or  1106  of each cell  404 ,  1084 , or  1104  is at a different specified location on the map. 
       FIG. 93  illustrates an IP structure  1200  consisting of OI structure  1100 , CC controller  1134 , and IG system  1182  formed with IG structure  804  and IG controller  1184 . Also see  FIGS. 38 b , 79 b , and 87 b   . Cell SF parts  406 ,  1086 , and  1106  again appear as rectangles, specifically squares. Networks  1186 ,  1188 , and  1190  extending from VC regions  106 ,  886 , and  906  to IG controller  1184  may respectively partly overlap networks  1136 ,  1138 , and  1140  respectively extending from regions  106 ,  886 , and  906  to CC controller  1134 . Networks  1142 ,  1144 , and  1146  again extend from controller  1134  respectively back to regions  106 ,  886 , and  906 . Structure  1100  and controller  1134  here operate the same as in IP structure  1130 . Structure  1100 , IG structure  804 , and IG controller  1184  here operate the same as in IP structure  1180 . 
     CC controller  1134  can again be a duration controller, similar to controller  652 , for adjusting CC duration Δt dr  subsequent to impact. Controller  1134  can alternatively be an intelligent controller, similar to controller  752 , for providing the supplemental impact assessment capability to determine whether an impact meeting the PP, AD, or FR cellular TH impact criteria has certain supplemental impact characteristics and, if so, for causing for causing CM cells  404 ,  1084 , or  1104  to temporarily appear as color X, Y, or Z. 
     IG controller  1184  can operate in various ways when controller  1134  is an intelligent controller. If a PAV image is desired regardless of whether the PP, AD, or FR supplemental impact criteria are, or are not, met, IG controller  1184  supplies the PP, AD, or FR PA identification signal in response to the expected location for print area  118 ,  898 , or  918  provided in the PP, AD, or FR cellular CI impact signals transmitted via network  1186 ,  1188 , or  1190 . A PP, AD, or FR PAV image is generated whenever the PP, AD, or FR cellular TH impact criteria are met. IG Controller  1184  usually provides the PP, AD, or FR PA identification signal in response to the PP, AD, or FR cellular CC initiation signal supplied from controller  1134  via a COM path  1202 . A PAV image is generated only when the PP, AD, or FR supplemental impact criteria are met. Impact simultaneously on SF zones  892  and  112  or/and  912  for both ways of operating controller  1184  is handled the same as just described except that the processing of the PA-location identifying information in the AD and PP or/and FR cellular CI impact signals is modified as described above in regard to IP structure  1180  for processing the AD and PP or/and FR cellular LI impact signals for impact simultaneously on zones  892  and  112  or/and  912 . 
     IG controller  1154  or  1184  may provide a screen activation/deactivation signal, transmitted via path  820 , to screen  810  for activating or deactivating it. Responsive to instruction  824 , controller  1154  or  1184  may provide a magnify/shrink signal the same as controller  806  or  846 . IG structure  804  here responds to the magnify/shrink signal the same as it responds to magnify/shrink signal provided by controller  806  or  846 . 
     Controller  1154  or  1184  preferably includes an image analyzer for analyzing each PAV image to determine whether it is a PP, AD, or FR PAV image or a CP PAV image and for providing an indication of the analysis. The analysis indication may be presented on screen  810 , e.g., as a part of the PAV image at a location spaced apart from the image print area of each print area  118 ,  898 , or  918  appearing in the PAV image. 
     The PP, AD, or FR supplemental impact criteria sometimes require that print area  118 ,  898 , or  918  be entirely inside SF zone  112 ,  892 , or  912 . This is typically expressed by the physical requirement that area  118  be spaced apart from the SF edges of interfaces  110  and  884  and each other part of the boundary of zone  112 , that area  898  be spaced apart from the SF edges of interfaces  884  and  904  and each other part of the boundary of zone  892 , or that area  918  be spaced apart from the SF edges of interfaces  904  and  910  and each other part of the boundary of zone  912 . For this purpose, CC controller  1114  or  1134 , often termed controller  1114 / 1134 , may maintain an electronic map of zones  112 ,  892 , and  912 , including the locations of the SF edges of interfaces  110 ,  884 ,  904 , and  910  and each other part of the boundaries of zones  112 ,  892 , and  912 . The PP, AD, or FR general supplemental impact information includes the location of OC area  116 ,  896 , or  916  on the map. Controller  1114 / 1134  determines the expected location of area  118 ,  898 , or  918  from the OC-area location and examines the map to determine whether area  118 ,  898 , or  918  is entirely inside zone  112 ,  892 , or  912 . 
     Image-collecting apparatus  808  in IP structures  1150 ,  1170 ,  1180 , and  1200  optionally functions as an OT control apparatus which optically tracks the movement of object  104  over surface  102  and which can be used in largely the ways described above for IP structures  800 ,  830 ,  840 , and  850  to cause color change for impacts of object  104  for which color change is desired and to substantially avoid causing color change for impacts of bodies for which color change is not desired. Path  826 A is replaced with a trio of COM paths (not shown) respectively extending from OT control apparatus  808  to VC regions  106 ,  886 , and  906 , specifically their PP, AD, and FR ISCC structures ( 132 ,  922 , and  924 ), in OI structure  900  or  1100 . The three COM paths replacing path  826 A in structure  1100  split into three groups of individual COM paths (not shown) respectively extending to all cells  404 ,  1084 , and  1104 , specifically their ISCC parts. 
     In a first expanded OT technique, OT control apparatus  808  interacts with VC region  106 ,  886 , or  906  for impact solely on SF zone  112 ,  892 , or  912  basically the same as apparatus  808  interacts with region  106  for impact on zone  112  in the first basic OT technique. Regions  106 ,  886 , and  906  are capable of being enabled to be capable of changing color at locations dependent on the object tracking and are normally disabled from being capable of changing color so as to normally respectively appear as PP color A, AD color B, and FR color C. The PP, AD, and FR ISCC structures ( 132 ,  922 , and  924 ) provide the enablable/disablable CC capability. 
     OT control apparatus  808  estimates where object  104  is expected to impact surface  102  according to the tracked movement of object  104  and provides a PP, AD, or FR general CC enable signal shortly prior to the impact if the tracking indicates that object  104  is expected to contact surface  102  at least partly in SF zone  112 ,  892 , or  912 . If object  104  is expected to contact zone  112 , the PP general CC enable signal, transmitted by a replacement for path  826 A to VC region  106  specifically the PP ISCC structure, at least partly identifies ID estimated OC area  116   #  (shown in  FIGS. 74 and 75  but not in  FIGS. 90-93 ). If object  104  is expected to contact zone  892  or  912 , the AD or FR general CC enable signal, also transmitted by a replacement for path  826 A to VC region  886  or  906  specifically the AD or FR ISCC structure, at least partly identifies ID estimated OC area (not shown in  FIGS. 90-93 ) spanning where object  104  is expected to contact zone  892  or  912 . Analogous to estimated area  116   # , the estimated OC area for contact with zone  892  or  912  is usually of roughly the same physical area as actual OC area  896  or  916  even though the estimated and actual OC areas (turn out to) differ in location along zone  892  or  912 . 
     An ID laterally oversize portion of VC region  106 ,  886 , or  906  is enabled to be capable of changing color in response to the PP, AD, or FR CC enable signal. The oversize portion of region  106  extends to oversize area  828  (shown in  FIGS. 74 and 75  but not in  FIGS. 90-93 ) of SF zone  112 . The oversize portion of region  886  or  906  extends to an ID oversize area (not shown in  FIGS. 90-93 ) of SF zone  892  or  912 . When region  106 ,  886 , or  906  includes structure besides the PP, AD, or FR ISCC structure, the PP, AD, or FR ISCC structure causes the oversize portion of region  106 ,  886 , or  906  to be enabled to be capable of changing color. Analogous to oversize area  828 , the oversize area of zone  892  or  912  encompasses and extends beyond the estimated OC area of zone  892  or  912  as well as usually being roughly concentric with its estimated OC area. Analogous to what occurs with oversize area  828 , OT control apparatus  808  and region  886  or  906 , specifically the AD or FR ISCC structure, operate so that the oversize area of zone  892  or  912  virtually always fully encompasses actual OC area  896  or  916 . 
     The PP IDVC portion ( 138 ), which is included in the oversize portion of VC region  106 , responds to object  104  impacting oversize area  828  at actual OC area  116  by temporarily appearing as changed color X if the impact meets the PP basic TH impact criteria. The AD IDVC portion ( 926 ) or FR IDVC portion, which is included in the oversize portion of VC region  886  or  906 , responds to object  104  impacting the oversize area of SF zone  892  or  912  at actual OC area  896  or  916  by temporarily appearing as altered color Y or modified color Z if the impact meets the AD or FR basic TH impact criteria. When region  106 ,  886 , or  906  includes structure besides the PP, AD, or FR ISCC structure, the PP ID ISCC segment ( 142 ), AD ID ISCC segment ( 928 ), or FR ID ISCC segment causes the PP, AD, or FR IDVC portion to temporarily appear as color X, Y, or Z. The AD and FR IDVC portions usually have approximately the same anticipation time period Δt ant  and enable-end time period Δt end  as the PP IDVC portion. 
     Simultaneous impact on SF zones  892  and  112  or/and  912  in IP structures  1150  and  1170  is preferably handled in the preferred way described above for  FIG. 79 . That is, the AD IDVC portion temporarily appears as color Y if the impact meets the CP basic TH impact criteria for the total OC area  896  and  116  or/and  916  where object  104  impacts zones  892  and  112  or/and  912 . The PP IDVC portion temporarily appears as color X if, besides impacting zone  892 , object  104  impacts zone  112 , and the FR IDVC portion temporarily appears as color Z if object  104  also impacts zone  912 . When VC region  106 ,  886 , or  906  includes structure besides the PP, AD, or FR ISCC structure, the AD ISCC segment causes the AD IDVC portion to temporarily appear as color Y. The PP or FR ID ISCC segment causes the PP or FR IDVC portion to temporarily appear as color X or Z if object  104  impacts zone  112  or  912 . 
     Cells  404 ,  1084 , and  1104  in IP structures  1180  and  1200  are enablable/disablable cells normally disabled from being capable of changing color. The oversize portion of VC region  106 ,  886 , or  906  is constituted with an ID group of cells  404 ,  1084 , or  1104  termed the PP, AD, or FR oversize cell group. Analogous to oversize area  828 , the oversize area of SF zone  892  or  912  consists of SF parts  1086  or  1106  of cells  1084  or  1104  in the AD or FR oversize cell group. Responsive to the PP, AD, or FR CC enable signal transmitted along a replacement for path  826 A, each cell  404 ,  1084 , or  1104  in the PP, AD, or FR oversize cell group is enabled to be capable of changing color. When region  106 ,  886 , or  906  includes structure besides the PP, AD, or FR ISCC structure, the ISCC part of each cell  404 ,  1084 , or  1104  in the PP, AD, or FR oversize cell group causes that cell  404 ,  1084 , or  1104  to be enabled to be capable of changing color. Each so-enabled cell  404 ,  1084 , or  1104  temporarily appears as color X, Y, or Z if the impact of object  404  on SF zone  112 ,  892 , or  912  causes that cell  404 ,  1084 , or  1104  to meet the PP, AD, or FR cellular TH impact criteria and temporarily become a CM cell. When region  106 ,  886 , or  906  contains structure besides the PP, AD, or FR ISCC structure, the ISCC part of each CM cell  404 ,  1084 , or  1104  causes it to temporarily appear as color X, Y, or Z. 
     In a second expanded OT technique, OT control apparatus  808  interacts with VC region  106 ,  886 , or  906  for impact solely on SF zone  112 ,  892 , or  912  basically the same as apparatus  808  interacts with region  106  for impact on zone  112  in the second basic OT technique. Apparatus  808  provides a PP, AD, or FR general impact tracking signal during at least part of tracking contact time period Δt cont  extending substantially from when object  104  impacts zone  112 ,  892 , or  912  to when object  104  leaves zone  112 ,  892 , or  912  according to the tracking. The PP, AD, or FR general impact tracking signal, which indicates that object  104  impacted zone  112 ,  892 , or  912 , is transmitted via a replacement for path  826 A to the PP IDVC portion ( 138 ), AD IDVC portion ( 926 ), or FR IDVC portion, specifically the PP ID ISCC segment ( 142 ), AD ID ISCC segment ( 928 ), or FR ID ISCC segment. The PP, AD, or FR IDVC portion responds to largely joint occurrence of the PP, AD, or FR tracking signal and the impact by temporarily appearing as color X, Y, or Z if the impact meets the PP, AD, or FR basic TH impact criteria. When region  106  contains structure besides the PP, AD, or FR ISCC structure ( 132 ,  922 , or  924 ), the PP, AD, or FR ISCC segment causes the PP, AD, or FR IVDC portion to temporarily appear as color X, Y, or Z. 
     Simultaneous impact on SF zones  892  and  112  or/and  912  in IP structures  1150  and  1170  is preferably handled by having the AD IDVC portion respond to largely joint occurrence of the AD general impact tracking signal and the impact by temporarily appearing as color Y if the impact meets the CP basic TH impact criteria for the total OC area  896  and  116  or/and  916  where object  104  impacts zones  892  and  112  or/and  912 . The PP IDVC portion temporarily appears as color X if, besides impacting zone  892 , object  104  impacts zone  112  while the FR IDVC portion temporarily appears as color Z if object  104  also impacts zone  912 . When VC region  106 ,  886 , or  906  contains structure besides the PP, AD, or FR ISCC structure, the AD ID ISCC segment causes the AD IDVC portion to temporarily appear as color Y. The PP or FR ID ISCC segment causes the PP or FR IDVC portion to temporarily appear as color X or Z for impact on zone  112  or  912 . 
     For IP structures  1180  and  1200 , the PP, FR, or AD IDVC portion consists of a PP, AD, or FR ID group of cells  404 ,  1084 , or  1104 . Each cell  404 ,  1084 , or  1104  in the PP, AD, or FR ID cell group responds to largely joint occurrence of the PP, AD, or FR general impact tracking signal, transmitted along a replacement for path  826 A, and object  104  impacting SF zone  112 ,  892 , or  912  by temporarily appearing as color X, Y, or Z if the impact causes that cell  404 ,  1084 , or  1104  to meet the PP, AD, or FR cellular TH impact criteria. When VC region  106 ,  886 , or  906  includes structure besides the PP, AD, or FR ISCC structure, the ISCC part of each cell  404 ,  1084 , or  1104  in the PP, AD, or FR ID cell group causes that cell  404 ,  1084 , or  1104  to temporarily appear as color X, Y, or Z. 
     In a third expanded OT technique, OT control apparatus  808  interacts with VC region  106 ,  886 , or  906  for impact solely on SF zone  112 ,  892 , or  912  basically the same as apparatus  808  interacts with region  106  for impact on zone  112  in the third basic OT technique. In particular, path  826 B is replaced with a trio of COM paths (not shown) respectively extending from regions  106 ,  886 , and  906 , specifically the PP, AD, and FR ISCC structures ( 132 ,  922 , and  924 ), in OI structure  900  or  1100  to apparatus  808 . The three COM paths replacing path  826 B in structure  1100  respectively consist of three groups of individual COM paths (not shown in  FIGS. 92 and 93 ) respectively extending from all cells  404 ,  1084 , and  1104 , specifically their ISCC parts, to apparatus  808 . 
     The PP IDVC portion ( 138 ), AD IDVC portion ( 926 ), or FR IDVC portion responds to object  104  impacting SF zone  112 ,  892 , or  912  at OC area  116 ,  896 , or  916  by providing a PP, AD, or FR general LI impact signal if the impact meets the PP, AD, or FR basic TH impact criteria. The PP, AD, or FR general LI impact signal, transmitted via a replacement for path  826 B to OT control apparatus  808 , identifies an expected location of print area  118 ,  898 , or  918  in zone  112 ,  892 , or  912 . When VC region  106 ,  886 , or  906  includes structure besides the PP, AD, or FR ISCC structure ( 132 ,  922 , or  924 ), the PP ID ISCC segment ( 142 ), AD ID ISCC segment ( 928 ), or FR ID ISCC segment provides the PP, AD, or FR LI impact signal. Apparatus  808  estimates where object  104  contacted surface  102  in zone  112 ,  892 , or  912  according to the tracking and provides a PP, AD, or FR general estimation impact signal indicative of the estimated PP, AD, or FR OC area spanning where object  104  is so estimated to have contacted surface  102  provided that the estimate of that contact is at least partly in zone  112 ,  892 , or  912 . Apparatus  808  then compares the PP, AD, or FR general LI impact signal to the PP, AD, or FR general estimation impact signal. If the comparison indicates that area  118 ,  898 , and  918  and the PP, AD, or FR estimated OC area at least partly overlap, apparatus  808  provides a PP, AD, or FR general CC initiation signal to the PP, AD, or FR IDVC portion, specifically the PP, AD, or FR ISCC segment, via a replacement for path  826 A. The PP, AD, or FR IDVC portion responds to the PP, AD, or FR CC initiation signal by temporarily appearing as color X, Y, or Z. When region  106 ,  886 , or  906  contains structure besides the PP, AD, or FR ISCC structure, the PP, AD, or FR segment causes the PP, AD, or FR IDVC portion to temporarily appear as color X, Y, or Z. 
     Simultaneous impact on SF zones  892  and  112  or/and  912  in IP structures  1150  and  1170  is preferably handled by having the AD IDVC portion, specifically the AD ID ISCC segment ( 928 ), respond to object  104  impacting zones  892  and  112  or/and  912  at OC areas  896  and  116  or/and  916  by providing an AD general LI impact signal if the impact meets the CP basic TH impact criteria for the total area  896  and  116  or/and  916  where object  104  impacts zones  892  and  112  or/and  912 . The PP IDVC portion, specifically the PP ID ISCC segment ( 142 ), provides a PP general LI impact signal if, besides impacting zone  892 , object  104  impacts zone  112 , and the FR IDVC portion, specifically the FR ID ISCC segment, provides an FR general LI impact signal if object  104  also impacts zone  912 . OT control apparatus  808  then interacts with the PP, AD, and FR IDVC portions the same as it interacts with each PP, AD, or FR IDVC portion for object  104  solely impacting zone  112 ,  892 , or  912 . 
     For IP structures  1180  and  1200 , each of multiple cells  404 ,  1084 , or  1104  for which the impact of object  104  on that cell&#39;s SF part  406 ,  1086 , or  1106  meets the PP, AD, or FR cellular TH impact criteria becomes part of a first ID group of cells  404 ,  1084 , or  1104  termed the PP, AD, or FR ID expected PA cell group. Cells  404 ,  1084 , or  1104  in the PP, AD, or FR ID expected cell group are PP, AD, or FR TH CM cells. Each cell  404 ,  1084 , or  1104 , specifically its ISCC part when VC region  106 ,  886 , or  906  contains structure besides the PP, AD, or FR ISCC structure, in the PP, AD, or FR expected cell group provides a PP, AD, or FR cellular LI impact signal identifying that cell&#39;s location in SF zone  112 ,  892 , or  912 . The PP, AD, or FR cellular LI impact signal of each cell  404 ,  1084 , or  1104  in the PP, AD, or FR expected PA cell group is provided along a corresponding one of a replacement for path  826 B to OT control apparatus  808 . SF parts  406 ,  1086 , or  1106  of cells  404 ,  1084 , or  1104  in the PP, AD, or FR expected PA cell group form the area expected for print area  118 ,  898 , or  918 . The PP, AD, or FR cellular LI impact signals of all cells  404 ,  1084 , or  1104  in the PP, AD, or FR expected PA cell group together form the PP, AD, or FR general LI impact signal. 
     OT control apparatus  808  estimates where object  104  contacted surface  102  according to the tracked movement of object  104  and provides the PP, AD, or FR general estimation impact signal to determine the estimated PP, AD, or FR OC area here consisting of SF parts  406 ,  1086 , or  1106  of a second ID group of cells  404 ,  1084 , or  1104  termed the PP, AD, or FR estimated-area cell group. For determining whether the estimated PP, AD, or FR OC area at least partly overlaps print area  118 ,  898 , or  918 , apparatus  808  determines whether any cell  404 ,  1084 , or  1104  is in both the PP, AD, or FR estimated-area cell group and the PP, AD, or FR expected PA cell group. If so, apparatus  808  provides the PP, AD, or FR general CC initiation signal. Each cell  404 ,  1084 , or  1104  in the PP, AD, or FR expected PA cell group responds to the PP, AD, or FR CC initiation signal, transmitted along a replacement for a path  826 A, by temporarily appearing as color X, Y, or Z. When VC region  106 ,  886 , or  906  includes structure besides the PP, AD, or FR ISCC structure, the ISCC part of each cell  404 ,  1084 , or  1104  in the PP, AD, or FR expected PA cell group causes that cell  404 ,  1084 , or  1104  to temporarily appear as color X, Y, or Z. 
     CC controller  1114  or  1134  alternatively performs all or part of the data processing performed by image-collecting apparatus  808  for IP structure  1170  or  1200  in the three expanded OT techniques essentially the same as CC controller  832  or  852  alternatively performs all or part the data processing performed by apparatus  808  for IP structure  830  or  850  in the three basic OT techniques. Controller  1114 / 1134  or the combination of controller  1114 / 1134  and apparatus  808  then functions as an OT control apparatus. Importantly, the three expanded OT techniques enable IP structures  1150 ,  1170 ,  1180 , and  1200  to distinguish between impacts of object  104  for which color change is desired and impacts of bodies for which color change is not desired essentially the same as in the three basic OT techniques. 
     Curve Smoothening 
     The boundaries of SF zones  112 ,  892 , and  912  may be somewhat rough due to SF irregularities and other deviations from ideality. SF boundary portions ideally straight may be significantly crooked. The perimeters of print areas  118 ,  898 , and  918  may likewise be somewhat rough due to irregularities in the shape of object  104  and irregularities along zones  112 ,  892 , and  912 . The SF-boundary/PA-perimeter roughness can create difficulty in determining whether area  118 ,  898 , or  918  meets a boundary of zone  112 ,  892 , or  912 , especially if area  118 ,  898 , or  918  is close to, e.g., less than 1 or 2 cm from, that boundary. 
     The SF-boundary/PA-perimeter roughness situation is illustrated in  FIGS. 94 a -94 d    which present four examples of the boundaries of SF zones  112 ,  892 , and  912  and the perimeters of print areas  118 ,  898 , and  918  for single impacts. In  FIG. 94 a   , area  898  having a perimeter  1210  is near the illustrated portion  1212  of the boundary, formed by an edge of interface  884 , between zones  112  and  892 . PA perimeter  1210 , ideally smoothly curved, and boundary portion  1212 , ideally straight, are irregular. Area  898  is seemingly far enough away from portion  1212  that area  898  does not meet portion  1212 . In  FIG. 94 b   , area  898  is likewise near the illustrated portion  1214  of the boundary, formed by an edge of interface  884 , between zones  112  and  892 . Boundary portion  1214 , ideally two straight lines meeting at a corner, is irregular. Area  898  is so close to portion  1214  that area  118  having a perimeter  1216 , also irregular, may be present in zone  112  as an extension of area  898 . 
     Turning to  FIG. 94 c   , print area  918  having a perimeter  1218  is near the illustrated portion  1220  of the boundary, formed by an edge of interface  904 , between SF zones  892  and  912 . PA perimeter  1218  and boundary portion  1220 , ideally smoothly curved, are irregular. It is unclear whether area  918  meets portion  1220  so that area  918  has extension  898  in zone  892 . In  FIG. 94 d   , print area  118  having a perimeter  1222  is near the illustrated portion  1224  of the boundary, formed by an edge of interface  110 , between SF zones  112  and  114 . PA perimeter  1222  and boundary portion  1224 , respectively ideally straight and smoothly curved lines meeting at a corner, are irregular. It is unclear whether area  118  meets portion  1224 . 
     Considerable clarity as to whether print area  118 ,  898 , or  918  meets a boundary of SF zone  112 ,  892 , or  912 , especially when PA perimeter  1210 ,  1218 , or  1222  is irregular or/and the boundary is irregular near area  118 ,  898 , or  918 , is achieved by providing an IP structure employing three-VC-region OI structure  900  or  1100 , including any of its embodiments, with an approximation capability in which the perimeters of areas  118 ,  898 , and  918  and adjacent portions of the boundaries of zones  112 ,  892 , and  912  are approximated as smooth curves. Examples of the smooth-curve approximations are illustrated in  FIGS. 95 a -95 d    respectively corresponding to  FIGS. 94 a -94 d   . Each item identified in  FIG. 95 a -95 c    or  95   d  with a reference symbol consisting of a number followed by an asterisk is an approximation to an item identified by a reference symbol formed with the same number in corresponding  FIG. 94 a -94 c    or  94   d.    
     The approximation capability, usually incorporated into IG controller  1154  or  1184  and performed with averaging software, entails first determining portion  1212 ,  1214 ,  1220 , or  1224  of the boundary where print area  118 ,  898 , or  918  is nearest the boundary. At least that boundary portion  1212 ,  1214 ,  1220 , or  1224  is approximated as a smooth boundary vicinity curve  1212 *,  1214 *,  1220 *, or  1224 * potentially having one or more sharp corners (as occurs in  FIG. 95 b    or  95   d ). PA perimeter  1210 ,  1218 , or  1222 , or a portion nearest the boundary, is similarly approximated as a smooth perimeter vicinity curve  1210 *,  1218 *, or  1222 *. Each pair of boundary and perimeter vicinity curves are compared to determine if they meet or overlap. An indication of the comparison is provided as output information. 
     The comparison indication preferably includes having the apparatus, e.g., controller  1154  or  1184 , performing the comparison provide screen  810  with the data for a curve-approximation image containing the two vicinity curves. Screen  810  then presents the curve-approximation image typically as a direct replacement for the PAV image. That is, the curve-approximation image typically appears in the same location on screen  810  as the PAV image which disappears when the curve-approximation image appears. Alternatively, screen  810  simultaneously presents both the curve-approximation image and the PAV image at screen locations close to each other so that observers can visually compare the images. 
     The comparison indication, including the curve-approximation image, for both the image-replacement situation and the simultaneous-image situation can be made available whenever a PAV image is automatically generated or whenever a PAV image is generated in response to instruction  822 . Inasmuch as a PAV image is automatically generated when the unsmoothened version of print area  118 ,  898 , or  918  meets the distance condition that a point in area  118 ,  898 , or  918  be less than or equal to a selected distance away from a selected location on surface  102  provided that the PP, AD. or FR basic TH impact criteria are met, area  118 ,  898 , or  918  in the curve-approximation image may not meet this distance condition due to the image smoothening. The same applies to areas  898  and  118  or/and  918  if object  104  simultaneously impacts SF zones  892  and  112  or  912  sufficient to meet the CP basic TH impact criteria. 
     Each of  FIGS. 95 a -95 d    is exemplary of the curve-approximation image.  FIG. 95 a    confirms that print area  898  does not meet boundary portion  1212  in the illustrated example.  FIGS. 95 b  and 95 d    indicate that print areas  898  and  118  reasonably respectively meet boundary portions  1214  and  1224  in those examples.  FIG. 95 c    indicates that print area  918  does not meet boundary portion  1220  in that example. 
     Controller  1154  or  1184  provides the approximation capability in response to the PP, AD, or/and FR general or cellular LI impact signals. The approximation capability can be provided for single-VC-region OI structure  100  or  400 , including any of its embodiments, subject to limiting the scope to VC SF zone  112  and adjoining surface such as that of FC SF zone  114 . The capability is then usually incorporated into controller  806  or  846  responding to the PP general or cellular LI impact signal. The approximation capability can be provided for double-VC-region OI structure  880  or  1080  subject to limiting the scope to VC SF zones  112  and  892  and adjoining surface such as that of FC SF zones  114  and  894 . If so, the capability is incorporated into an IG controller similar to controller  1154  or  1184  but only responding to the PP or/and AD general or cellular LI impact signals for providing control directed to structure  880  or  1080 . 
     Color Change Dependent on Location in Variable-Color Region of Single Normal Color 
     IP structure  700 ,  750 ,  830 , or  850  can provide a capability for the IDVC portion ( 138 ) of VC region  106  to appear as a selected one of multiple changed colors dependent on the location of print area  118  in SF zone  112 . The IDVC portion, specifically the ID ISCC segment ( 142 ), in a rudimentary general embodiment of structure  700  having this location-dependent CC capability responds to object  104  impacting OC area  116  by providing a principal general LI impact signal, instead of a CI impact signal, if the impact meets the principal basic TH impact criteria. The general LI impact signal again identifies an expected location of area  118  in zone  112 . Area  118  meets (or satisfies) one of p mutually exclusive location criteria LJ 1 , LJ 2 , . . . LJ p  for the location of area  118  in zone  112 , p being an integer greater than 1. Location criteria LJ 1 -LJ m  encompass all of zone  112  and respectively correspond to p specific changed colors XJ 1 , XJ 2 , . . . XJ p  which embody changed color X and which all materially differ from principal color A. More than one, usually all, of specific changed colors XJ 1 -XJ p  differ. 
     Intelligent controller  702  responds to the general LI impact signal by determining which location criterion LJ i  is satisfied by print area  118  and then providing a principal general CC initiation signal at a condition corresponding to that location criterion LJ i  where i here is an integer varying from 1 to p. The IDVC portion ( 138 ) responds to the initiation signal by temporarily appearing along area  118  as specific changed color XJ i  for that location criterion LJ i . When VC region  106  contains structure besides the ISCC structure ( 132 ), the ID ISCC segment ( 142 ) specifically causes the IDVC portion to temporarily appear as color XJ i . Since SF zone  112  normally appears as color A, the location-dependent CC capability enables area  118  to appear as one of two or more changed colors XJ 1 -XJ p  depending on where object  104  impacts zone  112 . 
     The IDVC portion ( 138 ), specifically the ID ISCC segment ( 142 ), in an advanced general embodiment of IP structure  700  having the location-dependent CC capability responds to object  104  impacting OC area  116  by providing a principal general CI impact signal if the impact meets the principal basic TH impact criteria. The general CI impact signal identifies principal general impact characteristics consisting of the location expected for print area  118  in SF zone  112  and principal general supplemental impact information, described above, for the impact. Responsive to the impact signal, controller  702  determines whether the general supplemental impact information meets the principal supplemental impact criteria and, if so, determines which location criterion LJ i  is met by area  118  and provides a principal general CC initiation signal at a condition corresponding to that location criterion LJ i . The IDVC portion responds to the initiation signal, if provided, by temporarily appearing as specific changed color XJ i  for that location criterion LJ i . When VC region  106  includes structure besides the ISCC structure ( 132 ), the ISCC segment specifically causes the IDVC portion to temporarily appear as color XJ i . The combination of the location-dependent CC capability and the supplemental assessment capability achieved with the supplemental impact criteria enables controller  702  to distinguish between impacts of object  104  for which color change is desired and impacts of other bodies for which color change is not desired and thereby to cause color change only at area  118  as one of two or more changed colors XJ 1 -XJ p  depending on where object  104  impacted zone  112 . 
     The location-dependent CC capability is the same in IP structure  830  with CC controller  832  implemented as an intelligent controller functioning the same as controller  702  in both rudimentary and advanced general embodiments respectively corresponding to the rudimentary and advanced general embodiments of IP structure  700 . The location-dependent CC capability is also the same in cell-containing IP structures  750  and  850  subject to addition of the cell-related operational details and, for structure  850 , implementing CC controller  852  as an intelligent controller functioning the same as controller  752  in both rudimentary and advanced cell-containing embodiments corresponding to the rudimentary and advanced general embodiments of structure  700 . 
     Each cell  404  in the rudimentary cell-containing embodiment specifically provides a principal cellular LI impact signal if the impact causes that cell  404  to meet principal cellular TH impact criteria and temporarily become a TH CM cell. The cellular LI impact signal identifies where SF part  406  of that TH CM cell  404  is located in SF zone  112 . Controller  752  or the intelligent implementation of controller  852  responds to the cellular impact signal of each TH CM cell  404  by providing it with a principal cellular CC initiation signal that causes it to temporarily become a full CM cell and temporarily appear along its part  406  of zone  112  as changed color XJ i  for location criterion LJ i  met by print area  118 . In the advanced cell-containing embodiment, each cell  404  provides a principal cellular CI impact signal if the impact causes that cell  404  to meet the principal cellular TH impact criteria and temporarily become a TH CM cell. The cellular impact signal identifies the above-described principal cellular supplemental impact information for the object impacting OC area  116  as experienced at that TH CM cell  404 . Responsive to the cellular impact signal of each TH CM cell  404 , controller  752  or the intelligent implementation of controller  852  combines the cellular supplemental impact information of that TH CM cell  404  and any other TH CM cell  404  to form the principal general supplemental impact information, determines whether the general supplemental impact information meets the supplemental impact criteria, and, if so, provides a principal cellular CC initiation signal for causing that TH CM cell  404  causes to temporarily become a full CM cell and temporarily appear along its part  406  of zone  112  as color XJ i  for criterion LJ i  met by area  118 . 
     VC region  106  preferably includes components  182  and  184  typically implemented as in OI structure  200 . ID segment  192  of IS component  182  provides the LI or CI impact signal in response to the impact if it meets the basic TH impact criteria. ID segment  194  of CC component  184  responds to the initiation signal (if provided) by causing the IDVC portion ( 138 ) to temporarily appear as specific changed color XJ i  for location criterion LJ i . met by print area  118 . 
     SF zone  112  has a perimeter. In one implementation of the location-dependent CC capability where integer p is 2, the location criteria consist of (i) first criterion LJ 1  that print area  118  adjoin the perimeter and (ii) second criterion LJ 2  that area  118  be entirely inside zone  112 . Changed color X is (i) first changed color XJ 1  if area  118  adjoins the perimeter and (ii) second changed color XJ 2  different from color XJ 1  if area  118  is entirely inside zone  112 . In another implementation of the location-dependent CC capability where p is again 2, the perimeter consists of multiple perimeter segments. The location criteria include (i) first criterion LJ 1  that area  118  adjoin a specified one of the perimeter segments and (ii) second criterion LJ 2  that area  118  be spaced apart from the specified perimeter segment. Color X is (i) changed color XJ 1  if area  118  adjoins the specified perimeter segment and (ii) changed color XJ 2  again different from color XJ 1  if area  118  is spaced apart from the specified perimeter segment. These two implementations sometimes achieve the same result. 
     IP structures  1110 ,  1130 ,  1170 , and  1200  can each provide a capability for the AD IDVC portion ( 926 ) or FR IDVC portion of VC region  886  or  906  to appear as a selected one of multiple altered or modified colors dependent on the location of print area  898  or  918  in SF zone  892  or  912  besides enabling the PP IDVC portion ( 138 ) of VC region  106  to appear as a selected one of multiple changed colors dependent on the location of print area  118  in SF zone  112 . The location-dependent CC capability in general rudimentary and advanced embodiments for the AD or FR IDVC portion is performed the same as the general rudimentary and advanced embodiments for the PP IDVC portion subject to q specific altered colors YK 1 , YK 2 , . . . YK q  which embody altered color Y and materially differ from color B or r specific changed colors ZL 1 , ZL 2 , . . . ZL r  which embody modified color Z and materially differ from color C where q or r is an integer greater than 1 replacing changed colors XJ 1 -XJ p , q or r replacing p, q mutually exclusive location criteria LK 1 , LK 2 , . . . LK q  or r mutually exclusive location criteria LL 1 , LL 2 , . . . LL r  replacing location criteria LJ 1 -LJ p , and color YK i  or ZL i  replacing color XJ i  where integer i varies from 1 to q or r for color YK i  or ZL i . 
     Recitations of VC region  886  or  906 , SF zone  892  or  912 , color B or C, the AD or FR IDVC portion, the AD or FR ISCC structure, the AD or FR ID ISCC segment, OC area  896  or  916 , print area  898  or  918 , an AD or FR general LI impact signal, the AD or FR basic TH impact criteria, an AD or FR general CC initiation signal, an AD or FR general CI impact signal, the AD or FR supplemental impact information, the AD or FR supplemental impact criteria, the AD or FR IS component including its AD or FR ID segment, and the AD or FR CC component including its AD or FR ID segment also respectively replace the preceding recitations of VC region  106 , SF zone  112 , color A, the PP IDVC portion, the PP ISCC structure, the PP ID ISCC segment, OC area  116 , print area  118 , the PP general LI impact signal, the PP basic TH criteria, the PP general CC initiation signal, the PP general CI impact signal, the PP supplemental impact information, the PP supplemental impact criteria, the PP IS component including its PP ID segment, and the PP CC component including its PP ID segment in the preceding description. In rudimentary and advanced cell-containing embodiments, recitations of cells  1084  or  1104 , an AD or FR cellular impact signal, AD or FR cellular supplemental impact information, and an AD or FR cellular initiation signal additionally respectively replace the preceding recitations of cells  404 , the PP cellular impact signal, the PP cellular supplemental impact information, and the PP cellular initiation signal. The preceding implementations of the location-dependent CC capabilities for which p is 2 extend to implementations in which q or r is 2 for each region  886  or  906  in each of IP structures  1110 ,  1130 ,  1170 , and  1200 . 
     In an example of the second implementation of the location-dependent CC capability for which p is 2 in IP structure  1110 ,  1130 ,  1170 , or  1200 , the specified segment of the perimeter of SF zone  112  is the edge of interface  884  where SF zones  112  and  892  meet along surface  102 . By arranging for changed color X to be (i) first changed color XJ 1  if print area  118  adjoins this interface edge and (ii) second changed color XJ 2  if area  118  is spaced apart from this interface edge, it can readily be determined whether object  104  impacted zone  112  at a location adjoining zone  892  or at a location spaced apart from zone  892  by simply looking at changed color X of area  118 . In particular, color X is (i) color XJ 1  if area  118  adjoins zone  892  and (ii) color XJ 2  if area  118  is spaced apart from zone  892 . 
     The preceding example can be reversed by setting q at 2 and arranging for altered color Y to be (i) first altered color YK 1  if print area  898  adjoins the preceding interface edge and (ii) second altered color YK 2  different from color YK 1  if area  898  is spaced apart from that interface edge. It can then readily be determined whether object  104  impacted SF zone  892  at a location adjoining SF zone  112  or at a location spaced apart from zone  112  by simply looking at altered color Y of area  898 . That is, color Y is (i) color YK 1  if area  898  adjoins zone  112  and (ii) color YK 2  if area  898  is spaced apart from zone  112 . The second implementation of the location-dependent CC capability for which p or r is 2 can similarly be applied to the edge of interface  890  where SF zones  892  and  912  meet so that color Y is (i) color YK 1  if area  898  adjoins zone  912  and (ii) color YK 2  if area  898  is spaced apart from zone  912  or modified color Z is (i) first modified color ZL 1  if print area  918  adjoins zone  892  and (ii) second modified color ZL 2  different from color ZL 1  if area  918  is spaced apart from zone  892 . These examples for p, q, or r being 2 are very helpful in making various determinations in sports as described below for  FIGS. 96-101 . 
     Controller  702  or  752  typically uses an electronic map of SF zone  112 , including the location of the SF edge of interface  110  and each other part of the boundary of zone  112 , to determine which location criterion LJ i  is satisfied by print area  118 . The same applies to controller  832  or  852  when it operates as an intelligent controller functioning the same as controller  702  or  752 . Controller  1114 / 1134  likewise typically uses an electronic map of SF zones  112 ,  892 , and  912 , including the locations of the SF edges of interfaces  110 ,  884 ,  904 , and  910  and each other part of the boundaries of zones  112 ,  892 , and  912  to determine which location criterion LJ i , LK i , or LL i  is satisfied by print area  118 ,  898 , or  918 . 
     The signals provided from and to OI structure  900  or  1100  via networks  1116 ,  1118 ,  1120 ,  1122 ,  1124 ,  1126 ,  1156 ,  1158 , and  1160  or  1136 ,  1138 ,  1140 ,  1142 ,  1144 ,  1146 ,  1186 ,  1188 , and  1190  in IP structures  1150  and  1170  or  1180  and  1200  may leave and enter OI structure  900  or  1100  via wires along its sides or/and along substructure  134 . Any of those wires leaving structure  900  or  1100  along its sides extend into adjoining material of one or more of FC regions  108 ,  888 , and  908 , into any other regions adjoining the sides of structure  900  or  1100 , or/and into open space. Part of the signal processing performed on the signals provided from structure  900  or  1100  via networks  1116 ,  1118 ,  1120 ,  1156 ,  1158 , and  1160  or  1136 ,  1138 ,  1140 ,  1186 ,  1188 , and  1190  to produce the signals provided to structure  900  or  1100  via networks  1122 ,  1124 , and  1126  or  1142 ,  1144 , and  1146  may be physically performed in structure  900  or  1100 , e.g., in FA layer  206  when VC region  106  is embodied as in any of OI structures  200 ,  270 , and  300  or  460 ,  480 , and  500  and in FA layer  946  when VC region  886  of structure  900  is embodied as in any of OI structures  930 ,  980 , and  1010 . Controllers  1114  and  1154  or  1134  and  1184  may thus partially merge into structure  900  or  1100 . 
     Sound Generation 
     Each IP structure  600 ,  650 ,  700 ,  750 ,  830 , or  850  optionally has sound-generating apparatus, usually provided by CC controller  602 ,  652 ,  702 ,  752 ,  832 , or  852 , for generating a specified audible sound indicating that object  104  has impacted SF zone  112  to produce print area  118 . The specified sound which is separate from any audible sound originating at OC area  116  due physically to object  104  impacting area  116 , i.e., due to sound waves generated by the impact, sound is usually indicative of the meaning for the appearance, including potentially changed color X, of print area  118 . Responsive to the PP general LI impact signal, the PP cellular LI impact signals, the PP general CI impact signal if the PP supplemental impact criteria are met, and the PP cellular CI impact signals if the PP supplemental impact criteria are met, structures  600 ,  650 ,  700 , and  750  respectively generate the specified sound substantially immediately after object  104  has left zone  112 . Structure  830  or  850  does the same in response to the PP general LI impact signal or the PP cellular LI impact signals for controller  832  or  852  implementing duration controller  602  or  652  and in response to the PP general CI impact signal or the PP cellular CI impact signals if the PP supplemental impact criteria are met for controller  832  or  852  implementing intelligent controller  702  or  752 . Controllers  602 ,  652 ,  702 ,  752 ,  832 , and  852  each provide a capability for a person to directly or remotely adjust (increase or decrease) the volume (nominal amplitude) of the sound. 
     Each of IP structures  600 ,  650 ,  700 ,  750 ,  830 , and  850  selectively generates the specified sound, or substantially no audible sound, if the PP basic TH or supplemental impact criteria consist of multiple sets of different PP basic TH or supplemental impact criteria respectively associated with different specific changed colors materially different from PP color A as described above. In that case, the sets of PP basic TH or supplemental impact criteria are respectively associated with multiple sound candidates. Each sound candidate consists of either substantially no audible sound or a selected audible sound different from at least one other selected audible sound. All the sound candidates usually differ. 
     If only one set of the PP basic TH or supplemental impact criteria can be met for an impact, each of IP structures  600  and  650  or  700  and  750  generates the specified sound as the sound candidate for the PP TH or supplemental impact criteria set met by the impact, IP structure  830  does the same for CC controller  832  implementing duration controller  652  or intelligent controller  752 , and IP structure  850  does the same for CC controller  852  implementing controller  652  or  752 . If more than one set of the PP basic TH or supplemental impact criteria can potentially be met for an impact, the sets of PP TH or supplemental impact criteria have respective PP basic TH or supplemental sound priorities. Each of structures  600  and  650  or  700  and  750  then generates the specified sound as the sound candidate for the PP TH or supplemental criteria of the highest PP TH or supplemental sound priority met by the impact. With the sets of PP TH or supplemental impact criteria having respective PP TH or supplemental sound priorities if more than one set of the PP TH or supplemental criteria can potentially be met for an impact, structure  830  does the same for controller  832  implementing controller  602  or  702 , and structure  850  does the same for controller  852  implementing controller  652  or  752 . 
     IP structure  600 ,  650 ,  700 ,  750 ,  830 , or  850  may not generate the specified sound when certain circumstances arise despite the above-described requirements for generating the sound having been met. This situation typically occurs when structure  600 ,  650 ,  700 ,  750 ,  830 , or  850  is part of a larger IP structure having multiple VC regions akin to VC region  106  and when object  104  simultaneously impacts two or more selected ones of those VC regions. The larger IP structure then generates either substantially no audible sound or a selected audible sound different from each audible sound generatable by structure  600 ,  650 ,  700 ,  750 ,  830 , or  850 . 
     Each IP structure  800 ,  830 ,  840 , or  850  optionally has sound-generating apparatus for generating such a specified audible sound if the above-described object-tracking indicates that object  104  is almost certainly going to impact SF zone  112 . For structure  800  or  840 , the sound-generating apparatus is incorporated into IG controller  806  or  846 , incorporated into image-collecting apparatus  808 , or provided by a separate apparatus (not shown). The same applies to structure  830  or  850  except that the sound-generating apparatus can also be incorporated into CC controller  832  or  852 . 
     Each of IP structures  1110  and  1170  or  1130  and  1200  has optional sound-generating apparatus, typically provided by CC controller  1114  or  1134 , for generating a specified audible sound indicating that object  104  has impacted one or more of SF zones  112 ,  892 , and  912  to produce one or more of print areas  118 ,  898 , and  918 . The specified sound is separate from any audible sound originating at one or more of OC areas  116 ,  896 , and  916  due physically to object  104  impacting one or more of areas  116 ,  896 , and  916 . Generation of the specified sound may depend on which of zones  112 ,  892 , and  912  is/are impacted by object  104 , e.g., the sound (a) is generated if object  104  solely impacts a specified one, or either of a specified two, of zones  112 ,  892 , and  912  to produce the corresponding one of areas  118 ,  898 , and  918 , (b) is not generated if object  104  solely impacts either of the remaining two, or the remaining one, of zones  112 ,  892 , and  912  to produce the corresponding one of areas  118 ,  898 , and  918 , and (c) selectively is, or is not, generated if object  104  simultaneously impacts at least one of the specified one or two of zones  112 ,  892 , and  912  to produce the corresponding one or two of areas  118 ,  898 , and  918  and at least one of the remaining two or one of zones  112 ,  912 , and  912  to produce the corresponding two or one of areas  118 ,  898 , and  918 . In an example, the sound is generated if object  104  solely impacts zone  112  to produce area  118  but is not generated if object  104  solely impacts zone  892  or  912  to produce area  898  or  918  or simultaneously impacts any two or three of zones  112 ,  892 , and  912  to produce the corresponding two or three of zones  118 ,  898 , and  918  and vice versa. Zones  112  and  912  are inverted, accompanied by inverting areas  118  and  918 , to produce a complementary example. 
     When generated for an impact solely on SF zone  112 ,  892 , or  912  to produce print area  118 ,  898 , or  918 , the specified sound is usually indicative of the meaning for the appearance, including potentially color X, Y, or Z, of area  118 ,  898 , or  918  and thus may differ depending on which of zones  112 ,  892 , and  912  is impacted by object  104 . For an impact simultaneously on zones  892  and  112  or/and  912  to produce areas  898  and  118  or/and  918  and cause the sound to be generated, the sound is similarly usually indicative of the meaning for the appearance, including potentially colors Y and X or/and Z, of areas  898  and  118  or/and  918  and may differ depending on which two or more of zones  112 ,  892 , and  912  are impacted by object  104 . Insofar as zones  112  and  892  or/and  912  are so impacted and the sound is generated, the sound may be the same as, or differ significantly from, the sound generated due to an impact solely on zone  112 ,  892 , or  912 . 
     Responsive to the AD and PP or/and FR general or cellular LI impact signals if the AD and PP or/and FR basic TH impact criteria are met for CC controller  1114  or  1134  implementing a controller analogous to duration controller  602  or  652  and responsive to the AD and PP or/and FR general or cellular CI impact signals if the AD and PP or/and FR supplemental impact criteria are met, or the CP supplemental impact criteria are met in the event that object  104  simultaneously impacts SF zones  892  and  112  or/and  912 , for controller  1114  or  1134  implementing a controller analogous to intelligent controller  702  or  752 , each of IP structures  1110  and  1170  or  1130  and  1200  ordinarily generates the specified sound substantially immediately after object  104  has left surface  102 . Structures  1110 ,  1130 ,  1170 , and  1200  each provide a capability for a person to directly or remotely adjust the sound&#39;s volume. If the sound differs depending on which of zones  112 ,  892 , and  912  is/are impacted by object  104 , the volume of each different sound preferably can be separately so adjusted. 
     If the PP, AD, or FR basic TH impact criteria consist of multiple sets of different PP, AD, or FR basic TH impact criteria respectively associated with different specific changed, altered, or modified colors materially different from PP color A, AD color B, or FR color C, the specified sound can be selectively generated, or not generated, for impact solely on SF zone  112 ,  892 , or  912  to produce print area  118 ,  898 , or  918  depending on which set of PP, AD, or FR basic TH impact criteria is met. The same applies to the PP, AD, or FR cellular TH impact criteria. Should the CP basic TH impact criteria consist of multiple sets of different CP basic TH impact criteria respectively associated with different specific altered colors materially different from AD color B and different specific changed colors materially different from PP color A or/and different specific modified colors materially different from FR color C, the sound can be selectively generated, or not generated, for impact simultaneously on zones  892  and  112  or/and  912  to produce areas  898  and  118  or/and  918  depending on which set of CP basic TH impact criteria is met. 
     Each IP structure  1150 ,  1170 ,  1180 , or  1200  optionally has sound-generating apparatus for generating such a specified sound if the above-described object-tracking indicates that object  104  is almost certainly going to impact one or more of SF zones  112 ,  892 , and  912 . For structure  1150  or  1180 , the sound-generating apparatus is incorporated into IG controller  1154  or  1184 , incorporated into image-collecting apparatus  808 , or provided by a separate apparatus (not shown). The same applies to structure  1170  or  1200  except that the sound-generating apparatus can also be incorporated into CC controller  1114  or  1134 . 
     Accommodation of Color Vision Deficiency 
     The invention&#39;s CC capability can readily accommodate the large majority of persons with color vision deficiency, commonly termed color blindness, in which the ability to perceive color differences is reduced. Color vision deficiency arises much more in men, reportedly present in 8% of men, than in women, reportedly present in 0.5% of women. Color vision deficiency usually occurs due to one or more of the three types of optical cones either operating improperly or being absent (including nonfunctioning). There are three basic types of color vision deficiency, namely monochromacy, dichromacy, and anomalous trichromacy. 
     Monochromacy, quite rare, arises when two of the three types of cone pigments, commonly termed blue, green, and red, are missing. Monochromacy also arises when all three cone pigments are missing so that only the rods provide a vision function. Vision is essentially reduced to black, white, and shades of gray. 
     Dichromacy, divided into protanopia, deuteranopia, and tritanopia, arises when one of the three types of cone pigments is missing. Protanopia, reportedly present in 1% of men, is caused by the absence of red cones. Persons with protanopia have great difficulty in distinguishing between red and green. The usual brightness of red, orange, and yellow is much reduced. Violet, lavender, and purple are indistinguishable from various shades of blue because their reddish components are strongly dimmed. Deuteranopia, reportedly present in 1% of men, is caused by the absence of green cones. Persons with deuteranopia have great difficulty in distinguishing between red and green but without the dimming of protanopia. Tritanopia, very rare, is caused by the absence of blue cones. Blue colors appear greenish while yellow and orange colors appear pinkish. 
     Anomalous trichromacy, divided into protanomaly, deuteranomaly, and tritanomaly, arises when one of the three cone pigments is altered in spectral sensitivity. Protanomaly, reportedly present in 1% of men, is caused by shifting of the spectral sensitivity of the red cones toward green. Red, orange, and yeilow appear somewhat shifted toward green and are somewhat dimmed. Deuteranomaly, reportedly present in 5% of men and thus the prevalent type of color vision deficiency, is caused by shifting of the spectral sensitivity of the green cones toward red. A deuteranomalous person has some difficulty in distinguishing between red, orange, yellow, and green but without the dimming of protanomaly. Tritanomaly, very rare, is caused by shifting of the spectral sensitivity of the blue cones toward green. Blues appear greenish while yellows and oranges appear pinkish. 
     Persons with color vision deficiency generally seem capable of clearly distinguishing sufficiently dark colors from sufficiently light colors even though they cannot distinguish the hues of certain colors from those of certain other colors. The invention take advantage of this to provide implementations of OI structure  100  and its embodiments, extensions, and variations, including OI structures  130 ,  180 ,  200 ,  240 ,  260 ,  270 ,  280 ,  300 ,  320 ,  330 ,  340 ,  350 ,  400 ,  410 ,  420 ,  430 ,  440 ,  450 ,  460 ,  470 ,  480 ,  490 ,  500 ,  880 ,  882 ,  900 ,  902 ,  920 ,  930 ,  960 ,  980 ,  990 ,  1010 ,  1080 ,  1082 ,  1100 , and  1102  and their embodiments, extensions, and variations, in which the colors in at least one, regularly at least two, and often all three of the following three pairs of colors, to the extent present (in these implementations), differ materially as generally viewed by persons having dichromacy, anomalous trichromacy, or monochromacy: PP color A and changed color X, AD color B and altered color Y, and FR color C and modified color Z. Similarly, the colors in at least one, regularly at least two, and often three or more of the following six additional pairs of colors, to the extent present, usually differ materially as generally viewed by persons having dichromacy, anomalous trichromacy, or monochromacy: colors A and B, colors B and C, colors X and Y, colors Y and Z, colors A and Z, and colors C and X. 
     In particular, the colors in at least one, regularly at least two, and often all three of color pairs A and X, B and Y, and C and Z, to the extent present, differ materially in lightness L* in CIE L*a*b* color space. The difference in lightness L* between the colors in at least one, regularly at least two, and often all of color pairs A and X, B and Y, and C and Z, is usually at least 60, preferably at least 70, more preferably at least 80, sometimes at least 90. Similarly, the colors in at least one, regularly at least two, and often three or more of the six additional color pairs A and B, B and C, X and Y, Y and Z, A and Z, and C and X, to the extent present, usually differ materially in lightness L*. The difference in lightness L* between the colors in at least one, regularly at least two, and often three or more of color pairs A and B, B and C, X and Y, Y and Z, A and Z, and C and X is likewise usually at least 60, preferably at least 70, more preferably at least 80, sometimes at least 90. 
     One of each color pair A and X, B and Y, or C and Z is a light color while the other of that color pair is a dark color compared to the light color. In order to achieve the preceding L* difference between colors A and B when VC regions  106  and  886  are both present, a selected one of colors A and B is a light color while the remaining one of colors A and B is a dark color compared to the light color. If colors A and B respectively are light and dark colors, colors X and Y respectively are dark and light colors, and vice versa. In order to achieve the preceding L* differences among colors A, B, and C when VC regions  106 ,  886 , and  906  are all present, color A, B, and C alternate between being light colors and dark colors respectively compared to the light colors. That is, if color A is a light color, color B is a dark color while color C is a light color and vice versa. If colors A, B, and C respectively are light, dark, and light colors, colors X, Y, and Z respectively are dark, light, and dark colors and vice versa. 
     The preceding selections of colors with VC regions  106  and  886  or VC regions  106 ,  886 , and  906  present are expected to fully accommodate almost any person having a standard type of dichromacy, anomalous trichromacy, or monochromacy. Nonetheless, it may sometimes be sufficient to only partly accommodate color vision deficiency, especially since monochromacy and some types of dichromacy and anomalous trichromacy are rare. In an exemplary implementation having regions  106  and  886 , the L* difference between the colors in each color pair A and B or A and X is at least 60 but the L* difference between colors B and Y is less than 60. In an exemplary implementation having regions  106 ,  886 , and  906 , the L* difference between the colors in each color pair A and B, A and X, or B and C is at least 60 but the L* difference between colors B and Y is less than 60. In another exemplary implementation having regions  106 ,  886 , and  906 , the L* difference between the colors in each color pair A and B, B and C, or B and Y is at least 60 but the L* difference between colors A and X is less than 60. The L* difference between colors C and Z in each of the last two implementations may be less than, or at least, 60. 
     Another way of partly accommodating color vision deficiency when the colors in at least one, regularly at least two, and often all of color pairs A and X, B and Y, and C and Z, to the extent present, differ materially as perceived by the standard human eye/brain is to basically restrict a selected one of each pair of colors A and X, B and Y, and C and Z from being any color from green to red in the visible spectrum or any color having a non-insignificant component of any color from green to red in the visible spectrum. Since the lower limit of the green wavelength range is approximately 490 nm and since the red wavelength range is at greater wavelength than the green wavelength range, this basic restriction devolves to restricting the selected one of each pair of colors A and X, B and Y, and C and Z from being any color having a wavelength of approximately 490 nm or more or any color having a non-insignificant component at a wavelength of approximately 490 nm or more. The basic restriction essentially limits the selected one of each of these three pairs of colors to being violet, blue, or shades of violet or blue. 
     The remaining one of each pair of colors A and X, B and Y, and C and Z is not so restricted. By so choosing colors A, B, C, X, Y, and Z to the extent present, persons with the general red-green color vision deficiencies of protanomaly, deuteranomaly, protanopia, and deuteranopia are generally expected to be readily able to rapidly distinguish between colors A and X, between colors B and Y, and between colors C and Z even though those persons may not recognize certain of colors A, B, C, X, Y, and Z as perceived by the standard human eye/brain. Since persons with protanomaly, deuteranomaly, protanopia, and deuteranopia constitute the vast majority of people with color vision deficiency, the selection of colors A, B, C, X, Y, and Z in this basic restriction is expected to accommodate the vast majority of color vision deficient persons. 
     In an exemplary implementation of the preceding way of partly accommodating color vision deficiency when VC regions  106  and  886  are present and when colors A and B differ materially as perceived by the standard human eye/brain, the basic restriction of not being any color from green to red in the visible spectrum or any color having a non-insignificant component of any color from green to red in the visible spectrum is placed either on colors A and Y or on colors X and B. If VC region  906  is also present with colors B and C differing materially as perceived by the standard human eye/brain, the basic restriction of not being any color from green to red in the visible spectrum or any color having a non-insignificant component of any color from green to red in the visible spectrum is placed either on colors A, Y, and C or on colors X, B, and Z. 
     The preceding way of partly accommodating color vision deficiency is extended to persons with tritanomaly and tritanopia by additionally restricting the remaining one of each pair of colors A and X, B and Y, and C and Z from being any color from violet to yellow in the visible spectrum or any color having a non-insignificant component of any color from violet to yellow in the visible spectrum. Since the upper limit of the yellow wavelength range is approximately 590 nm and since the violet wavelength range is at lower wavelength than the yellow wavelength range, this additional restriction devolves to restricting the selected one of each pair of colors A and X, B and Y, and C and Z from being any color having a wavelength of approximately 590 nm or less or any color having a non-insignificant component at a wavelength of approximately 590 nm or less. The additional restriction effectively limits the remaining one of each of these three pairs of colors to being orange, red, or shades of orange or red. By so choosing the remaining one of each pair of colors A and X, B and Y, and C and Z, persons with the general blue-yellow color vision deficiencies of tritanomaly and tritanopia, are generally expected to be readily able to rapidly distinguish between colors A and X, between colors B and Y, and between colors C and Z even though those persons may not recognize certain of colors A, B, C, X, Y, and Z as perceived by the standard human eye/brain. 
     In an exemplary implementation of the preceding way of additionally partly accommodating color vision deficiency when VC regions  106  and  886  are present and when colors A and B differ materially as perceived by the standard human eye/brain, the basic restriction of not being any color from green to red in the visible spectrum or any color having a non-insignificant component of any color from green to red in the visible spectrum is again placed either on colors A and Y or on colors X and B. The additional restriction of not being any color from violet to yellow in the visible spectrum or any color having a non-insignificant component of any color from violet to yellow in the visible spectrum is placed on colors X and B if the basic restriction is placed on colors A and Y and vice versa. If VC region  906  is also present with colors B and C differing materially as perceived by the standard human eye/brain, the basic restriction of not being any color from green to red in the visible spectrum or any color having a non-insignificant component of any color from green to red in the visible spectrum is again placed either on colors A, Y, and C or on colors X, B, and Z. The additional restriction of not being any color from violet to yellow in the visible spectrum or any color having a non-insignificant component of any color from violet to yellow in the visible spectrum is placed on colors X, B, and Z if the basic restriction is placed on colors A, Y, and C and vice versa. 
     Tennis Implementations 
     Many sports, such as tennis, employ sports-playing structures having finite-width lines which define penalty/reward decisions or/and result in temporary play stoppage depending on whether an object impacts the sports-playing structure at, or on one side of, any of the lines. The object can be a sports instrument, e.g., a ball, or a person such as a player including the person&#39;s footwear and other clothing. The present CC capability can be provided (or installed) at each line and directly along both edges of each line. However, the CC capability is often used to a lesser extent for various reasons, including keeping the cost down. If so, location priorities are employed in determining where to provide the CC capability. 
     With the foregoing in mind, all lines in this section dealing with tennis and in the next section dealing with other sports are of finite width except as otherwise indicated. Providing CC capability “at” a line means that CC capability is provided across essentially the entire width of the line. CC capability may be present at part or all of the line&#39;s length. Providing CC capability “directly along” an edge of a line means that CC capability is provided in area adjoining that edge of the line. The line-adjoining area may encompass part or all of the line&#39;s length. One edge of each line defining a penalty/reward/play-stoppage decision is termed its critical edge because that edge is the demarcating location for the penalty/reward/play-stoppage decision. That is, the penalty or reward or/and temporary play stoppage applies to one or more types of contact occurring at area directly along one side of the critical edge and not to such contact occurring at area directly along the other side of the critical edge. 
     “IB” and “OB” again respectively mean inbounds and out-of-bounds. For a sport having an IB area at least partly separated from an OB area by a closed boundary line that forms part of the IB or OB area, the “inside” edge of the boundary line is the edge meeting or lying in the IB area. The “outside” edge is the edge lying in or meeting the OB area. The critical edge of the boundary line is (a) its inside edge if the line lies in the OB area so as to meet the IB area and (b) its outside edge if the line lies in the IB area so as to meet the OB area. 
     Recitations of IDVC portion  138 , OC area  116 , and print area  118  of a VC structure portion or part hereafter respectively mean portion  138  and areas  116  and  118  of a unit of VC region  106  in the structure portion or part. Recitations of IDVC portion  926 , OC area  896 , and print area  898  of a VC structure portion or part similarly hereafter respectively mean portion  926  and areas  896  and  898  of a unit of VC region  886  in the structure portion or part. Recitations of an FR IDVC portion, OC area  916 , and print area  918  of a VC structure portion or part hereafter respectively mean the FR IDVC portion and areas  916  and  918  of a unit of VC region  906  in the structure portion or part. 
     The present CC capability is preferably at least provided as a unit of VC region  106  (or  906 ) having SF zone  112  (or  912 ) situated in area, usually elongated, extending directly along the critical edge of a line defining a penalty/reward/play-stoppage decision. Providing the CC capability at this highest priority location directly along the line&#39;s critical edge enables an observer, e.g., a player or an official, to readily visually determine whether there is any space between the critical edge and the space beyond the critical edge so that the penalty/reward/play-stoppage decision can quickly be made. With the CC capability provided at the highest priority location, the CC capability may also be provided as a unit of VC region  886  having SF zone  892  situated at that line as the next (or second) highest CC location priority. Providing the CC capability at the next highest priority location further assists the observer in confirming whether any space is present between the critical edge and the space beyond the critical edge. Since the designations “ 886 ” and “ 106 ” (or “ 906 ”) are arbitrary, region  886  and region  106  (or  906 ), along with zone  892  and zone  112  (or  912 ), can be reversed. 
     Rules of tennis generally require that the lines of a tennis court be the same color. The court lines are usually white or nearly white. Tennis rules generally require that remainder of the IB playing area be a color contrasting to that of the lines. For a tennis court used for singles and doubles, the servicecourts, backcourts, and doubles alleys are usually uniformly of a single color clearly contrasting to that of the lines. The OB playing area is uniformly, at least along the (outer) boundary of the IB area and commonly for at least several meters away from that boundary, a color contrasting with the line color. 
     Despite tennis rules, World Team Tennis utilizes tennis courts in which the servicecourts, backcourts, and alleys are of multiple different colors. With the court lines being the usual white, World Team Tennis commonly uses the following combination of four materially different non-white colors. Both backcourts are a first non-white color. One pair of diagonally opposite servicecourts are a second non-white color. The other pair of diagonally opposite servicecourts are a third non-white color. The alleys are a fourth non-white color. 
     Using the reference symbols for the tennis court in  FIG. 1 , the following definitions apply to the tennis IP structures described below for  FIGS. 96 and 97 . Each pair of adjoining servicecourts  38  separated by the imaginary or real line below net  32  constitute net-separated servicecourts. Baseline  28  and serviceline  34  on the same side of the imaginary/real net line below net  32  constitute associated lines. The part of each doubles alley  48  extending between a baseline  28  and the net line constitutes a half alley. The two half alleys of each alley  48  constitute net-separated half alleys. Each tennis court has a longitudinal axis running lengthwise through the center of centerline  36  and a transverse axis formed by the net line. Each half court has a straight imaginary extended serviceline running lengthwise through the center of serviceline  34  in that half court and past both alleys  48 . Singles sidelines  30  and baselines  28 , insofar as they extend between sidelines  30 , form a closed boundary line  28 / 30  for singles IB area  22 . Doubles sidelines  46  and baselines  28  form a closed boundary line  28 / 46  for doubles IB area  42 . 
     The adjectives “left”, “right”, “far”, and “near” are used to distinguish identically shaped SF areas in the tennis courts of  FIGS. 96 and 97  relative to a location at the center of baseline  28  closest to the bottom of each figure. The inside and outside edges of an elongated straight VC area portion, part, or segment adjoining a court line respectively are the edge adjoining the line and the edge opposite the line-adjoining edge. “BC”, “SC”, “HA”, and “QC” hereafter respectively mean backcourt, servicecourt, half-alley, and quartercourt. “LA”, “BLA”, “CLA”, “SLA”, and “SVLA” hereafter respectively mean line-adjoining, baseline-adjoining, centerline-adjoining, sideline-adjoining, and serviceline-adjoining. A straight segment of a straight item means one of a plurality of straight segments arranged lengthwise in the item. Each recitation of a “ball” or “balls” in this section means a tennis ball or tennis balls. 
     A point in tennis usually begins with tennis service consisting of an effort by one player, the server, positioned at a location behind a baseline  28  and to one side of the center mark on that line  28  to serve a ball over net  32  and into diagonally opposite servicecourt  38 . A ball hit by the server is sometimes termed a served ball until the ball impacts surface  102  and is hit by another player, the receiver, located on the opposite side of net  32  from the server. If a served ball is “in”, return play begins with an effort by the receiver to return the served ball back over net  32 . If the receiver fails to return the served ball over net  32 , return play ends abruptly. If the receiver returns the served ball over net  32  so that the served ball lands “in”, return play continues as the players hit the ball back and forth over net  32  until the ball finally impacts surface  102  “out” to end the point and return play. A ball hit during any tennis stoke subsequent to tennis service, including a return of the served ball, is sometimes termed a returned ball. 
     Finite-width court lines  28 ,  30 ,  34 ,  36 , and  46  are of uniform color across them during the normal state. Each servicecourt  38 , backcourt  40 , or doubles half alley is of uniform color across that servicecourt  38 , backcourt, or half alley during the normal state. Doubles OB playing area  44  is of uniform color along the perimeter of doubles IB playing area  42  during the normal state. In addition to contrastingly differing from the normal-state line color, the normal-state color of each of IB court areas  38  and  40 , each half alley, and OB area  44  along the boundary of IB area  42  can potentially differ from the normal-state color of each other of court areas  38  and  40 , each half alley, and area  44  along the boundary of area  42 . 
       FIG. 96  illustrates a tennis IP structure  1230  containing OI structure  880  or  900  or, preferably, cell-containing OI structure  1080  or  1100  incorporated into a tennis court suitable for singles and doubles to form a tennis-playing structure having CC capability that assists in determining whether object  104  embodied with a ball is “in” or “out” when it impacts surface  102  in the immediate vicinity of a selected tennis line. The tennis-playing structure includes net  32 . For doubles, surface  102  consists of OB area  44  and IB area  42  formed with four servicecourts, two backcourts, two doubles alleys, and nine court lines consisting of near and far baselines  28 N and  28 F (collectively “baselines  28 ”), left and right singles sideline  30 L and  30 R (collectively “singles sidelines  30 ”), near and far servicelines  34 N and  34 F (collectively “servicelines  34 ”), centerline  36 , and left and right doubles sidelines  46 L and  46 R (collectively “doubles sidelines  46 ”). Lines  28 ,  30 ,  34 ,  36 , and  46  here are arranged the same as in  FIG. 1 . 
     The servicecourts consist of near left, near right, far left, and far right servicecourts  38 NL, NR,  38 FL, and  38 FR (collectively “servicecourts  38 ”) arranged the same relative to net  32  as servicecourts  38  in  FIG. 1 . Servicecourts  38 NL and  38 NR are in the near half court. Servicecourts  38 FL and  38 FR are in the far half court. Centerline  36  separates net-separated servicecourts  38 NR and  38 FR from net-separated servicecourts  38 NL and  38 FL. The backcourts consist of near and far backcourts  40 N and  40 F (collectively “backcourts  40 ”). Backcourt  40 N or  40 F is separated from servicecourts  38 NL and  38 NR or  38 FL and  38 FR by serviceline  34 N or  34 F. 
     The doubles alleys consist of left and right doubles alleys  48 L and  48 R (collectively “alleys  48 ”). Doubles alley  48 L is separated from servicecourts  38 NL and  38 FL or  38 NR and  38 FR by singles sideline  30 L or  30 R and toward the left or right from OB area  44  by doubles sideline  46 L or  46 R. Baseline  28 N or  28 F separates alleys  48  and backcourt  40 N or  40 F from OB area  44  toward the near or far end of the tennis court. The net line divides (a) left alley  48 L into near left and far left half alleys  48 NL and  48 FL respectively in the near and far half courts and (b) right alley  48 R into near right and far right half alleys  48 NR and  48 FR respectively in the near and far half courts. The court thus has four doubles half alleys  48 NL,  48 NR,  48 FL, and  48 FR (collectively “half alleys  48 H”). 
     IP structure  1230  is a full-line CC structure that provides CC capability at, and directly along both edges of, the entire length of each court line  28 ,  30 ,  34 ,  36 , or  46 . In particular, lines  28 ,  30 ,  34 ,  36 , and  46  form a composite VC singles/doubles line area  1232 T consisting of near and far VC singles/doubles line area  1232 N and  1232 F respectively in the near and far half courts. Each VC singles/doubles line area  1232 N or  1232 F consists of twelve elongated straight continuous VC line area parts  1232 ENL,  1232 ENC,  1232 ENR,  1232 SNL,  1232 SNR,  1232 ANL,  1232 BNL,  1232 ANR,  1232 BNR,  1232 CN,  1232 DNL, and  1232 DNR or  1232 EFL,  1232 EFC,  1232 EFR,  1232 SFL,  1232 SFR,  1232 AFL,  1232 BFL,  1232 AFR,  1232 BFR,  1232 CF,  1232 DFL, and  1232 DFR (collectively “ 1232 ”). VC line area parts  1232  in each half court variously end at the net line and the intersections of lines  28 ,  30 ,  34 ,  36 , and  46  in that half court. 
     VC line parts  1232 ENL,  1232 ENC, and  1232 ENR respectively lying fully along the near ends of half alley  48 NL, backcourt  40 N, and half alley  48 NR form near baseline  28 N. VC line parts  1232 EFL,  1232 EFC, and  1232 EFR respectively lying fully along the far ends of half alley  48 FL, backcourt  40 F, and half alley  48 FR form far baseline  28 F. VC line parts  1232 BNL,  1232 ANL,  1232 AFL, and  1232 BFL respectively lying fully along backcourt  40 N, servicecourts  38 NL and  38 FL, and backcourt  40 F and jointly lying fully along alley  48 L form left singles sideline  30 L. VC line parts  1232 BNR,  1232 ANR,  1232 AFR, and  1232 BFR respectively lying fully along backcourt  40 N, servicecourts  38 NR and  38 FR, and backcourt  40 F and jointly lying fully along alley  48 R form right singles sideline  30 R. VC line parts  1232 ANL and  1232 BNL,  1232 ANR and  1232 BNR,  1232 AFL and  1232 BFL, or  1232 AFR and  1232 BFR form a straight VC QC singles sideline area part  1232 QNL,  1232 QNR,  1232 QFL, or  1232 QFR. 
     VC line parts  1232 SNL and  1232 SNR or  1232 SFL and  1232 SFR respectively lying fully along servicecourts  38 NL and  38 NR or  38 FL and  38 FR and jointly lying fully along backcourt  40 N or  40 F form serviceline  34 N or  34 F. VC line parts  1232 CN and  1232 CF (collectively “ 1232 C”) form centerline  36 . VC line parts  1232 DNL and  1232 DFL or  1232 DNR and  1232 DFR lying fully along alley  48 L or  48 R form doubles sideline  46 L or  46 R. 
     Each VC line area part  1232  embodies one or more units of SF zone  892  (of one or more units of VC region  886 ) in a plurality of larger units of a specified one of OI structures  900  and  1100 . Each such larger unit contains a pentad of consecutively adjoining color regions  108 ,  106 ,  886 ,  906 , and  908 . In the multiple-unit situation, a line part  1232  is allocated into (or consists of) multiple straight VC area segments, each embodying a unit of zone  892  in a different one of the pentad units. AD color B for zone  892  in each pentad unit is the color of VC line area  1232 T during the normal state and, as dealt with below, is usually the same in every pentad unit. As also dealt with below, altered color Y of print area  898  of zone  892  in each pentad unit is usually the same color, materially different from color B, in every pentad unit during the changed state. 
     Each near servicecourt  38 NL or  38 NR is partly occupied with a ␣-shaped individual near VC IB CLA SC area portion  1240 NL or  1240 NR consisting of three elongated straight near VC LA SC area parts  1240 ANL,  1240 SNL, and  1240 CNL or  1240 ANR,  1240 SNR, and  1240 CNR respectively lying fully along part  1232 ANL or  1232 ANR of (closest) singles sideline  30 L or  30 R, part  1232 SNL or  1232 SNR of near (closest) serviceline  34 N, and near part  1232 CN of centerline  36 . Each far servicecourt  38 FL or  38 FR is partly occupied with a ␣-shaped individual far VC IB CLA SC area portion  1240 FL or  1240 FR consisting of three elongated straight far VC LA SC area parts  1240 AFL,  1240 SFL, and  1240 CFL or  1240 AFR,  1240 SFR, and  1240 CFR respectively lying fully along part  1232 AFL or  1232 AFR of (closest) singles sideline  30 L or  30 R, part  1232 SFL or  1232 SFR of far (closest) serviceline  34 F, and far part  1232 CF of centerline  36 . VC SC portions  1240 NL,  1240 NR,  1240 FL, and  1240 FR (collectively “ 1240 ”) are usually mirror images about the court&#39;s longitudinal and transverse axes. SC portions  1240 NL and  1240 FL or  1240 NR and  1240 FR form a rectangular annular composite VC IB CLA SC area portion  1240 L or  1240 R in which singles SLA SC parts  1240 ANL and  1240 AFL or  1240 ANR and  1240 AFR are continuous and in line with each other and in which CLA SC parts  1240 CNL and  1240 CFL or  1240 CNR and  1240 CFR are continuous and in line with each other. 
     Each backcourt  40 N or  40 F is partly occupied with a rectangular annular VC IB SVLA BC area portion  1242 N or  1242 F consisting of four elongated straight VC LA BC area parts  1242 EN,  1242 SN,  1242 BNL, and  1242 BNR or  1242 EF,  1242 SF,  1242 BFL, and  1242 BFR respectively lying fully along central part  1232 ENC or  1232 EFC of (closest) baseline  28 N or  28 F, associated (closest) serviceline  34 N or  34 F and thus serviceline parts  1232 SNL and  1232 SNR or  1232 SFL and  1232 SFR, part  1232 BNL or  1232 BFL of singles sideline  30 L, and part  1232 BNR or  1232 BFR of singles sideline  30 R. VC BC portions  1242 N and  1242 F (collectively “ 1242 ”) are usually symmetrical about the court&#39;s longitudinal axis and mirror images about the court&#39;s transverse axis. 
     Each SVLA BC part  1242 SN or  1242 SF consists of three elongated straight VC SVLA BC area parts (or subparts)  1242 SNL,  1242 SNC, and  1242 SNR or  1242 SFL,  1242 SFC, and  1242 SFR respectively termed left end, central, and right end area parts. Each central SVLA BC part  1242 SNC or  1242 SFC lies fully along the segments of serviceline parts  1232 SNL and  1232 SNR or  1232 SFL and  1232 SFR situated between imaginary extensions of the outside edges of CLA SC parts  1240 CNL and  1240 CNR or  1240 CFL and  1240 CFR into backcourt  40 N or  40 F. Each end SVLA BC part  1242 SNL,  1242 SNR,  1242 SFL, or  1242 SFR lies fully along the remainder of serviceline part  1232 SNL,  1232 SNR,  1232 SFL, or  1232 SFR. 
     Each half alley  48 NL,  48 NR,  48 FL, or  48 FR is partly occupied with a ␣-shaped individual near VC IB singles SLA HA area portion  1244 NL,  1244 NR,  1244 FL, or  1244 FR consisting of four elongated straight individual near VC LA HA area parts  1244 DNL,  1244 ENL,  1244 BNL, and  1244 ANL,  1244 DNR,  1244 ENR,  1244 BNR, and  1244 ANR,  1244 DFL,  1244 EFL,  1244 BFL, and  1244 AFL, or  1244 DFR,  1244 EFR,  1244 BFR, and  1244 AFR. VC HA portions  1244 NL,  1244 NR,  1244 FL, and  1244 FR (collectively “ 1244 ”) are usually mirror images about the court&#39;s longitudinal and transverse axes. Near HA parts  1244 DNL and  1244 ENL or  1244 DNR and  1244 ENR respectively lie fully along part  1232 DNL or  1232 DNR of (closest) doubles sideline  46 L or  46 R and end part  1232 ENL or  1232 ENR of near (closest) baseline  28 N. Far HA parts  1244 DFL and  1244 EFL or  1244 DFR and  1244 EFR respectively lie fully along part  1232 DFL or  1232 DFR of (closest) doubles sideline  46 L or  46 R and end part  1232 EFL or  1232 EFR of far (closest) baseline  28 F. 
     Each left singles SLA HA part  1244 ANL or  1244 AFL lies fully along left singles sideline part  1232 ANL or  1232 AFL and the segment of left singles sideline part  1232 BNL or  1232 BFL situated between part  1232 ANL or  1232 AFL and an imaginary leftward extension of the outside edge of SVLA BC part  1242 SN or  1242 SF. Each right singles SLA HA part  1244 ANR or  1244 AFR lies fully along right singles sideline part  1232 ANR or  1232 AFR and the segment of right singles sideline part  1232 BNR or  1232 BFR situated between part  1232 ANR or  1232 AFR and an imaginary rightward extension of the outside edge of BC part  1242 SN or  1242 SF. Each other singles SLA HA part  1244 BNL,  1244 BNR,  1244 BFL, or  1244 BFR extends fully along the remainder of singles sideline part  1232 BNL,  1232 BNR,  1232 BFL, or  1232 BFR. Singles SLA HA parts  1244 ANL and  1244 BNL,  1244 ANR and  1244 BNR,  1244 AFL and  1244 BFL, or  1244 AFR and  1244 BFR are continuous and in line with each other to form a straight VC singles SLA QC HA area part  1244 QNL,  1244 QNR,  1244 QFL, or  1244 QFR lying fully along singles sideline part  1232 QNL,  1232 QNR,  1232 QFL, or  1232 QFR. SLA HA portions  1244 NL and  1244 FL or  1244 NR and  1244 FR form a rectangular annular composite VC IB SLA alley area portion  1244 L or  1244 R in which doubles SLA HA parts  1244 DNL and  1244 DFL or  1244 DNR and  1244 DFR are continuous and in line with each other and in which singles SLA HA parts  1244 ANL and  1244 AFL or  1244 ANR and  1244 AFR are continuous and in line with each other. 
     Doubles OB area  44  is partly occupied with two ␣-shaped individual VC doubles OB BLA area portions  1246 N and  1246 F (collectively “ 1246 ”) together lying fully along baselines  28  and sidelines  30  on opposite respective near and far sides of the net line so as to fully surround doubles IB area  42 . VC OB portions  1246  are usually symmetrical about the court&#39;s longitudinal axis and mirror images about the court&#39;s transverse axis. Each doubles OB portion  1246 N or  1246 F consists of five elongated straight VC doubles OB LA area parts  1246 DNL,  1246 ENL,  1246 ENC,  1246 ENR, and  1246 DNR or  1246 DFL,  1246 EFL,  1246 EFC,  1246 EFR, and  1246 DFR. 
     Doubles OB parts  1246 ENL,  1246 ENC, and  1246 ENR or  1246 EFL,  1246 EFC, and  1246 EFR, respectively termed left end, central, and right end BLA area parts, are continuous and in line with one other to form a straight composite VC doubles OB BLA area part  1246 EN or  1246 EF. Central OB BLA part  1246 ENC or  1246 EFC lies fully along central baseline part  1232 ENC or  1232 EFC and the segments of end baseline parts  1232 ENL and  1232 ENR or  1232 EFL and  1232 EFR situated between part  1232 ENC or  1232 EFC and imaginary extensions of the outside edges of singles SLA HA parts  1244 BNL and  1244 BNR or  1244 BFL and  1244 BFR. Each end OB BLA part  1246 ENL,  1246 ENR,  1246 EFL, or  1246 EFR lies fully along the remainder of end baseline part  1232 ENL,  1232 ENR,  1232 EFL, or  1232 EFR. 
     Doubles OB part  1246 DNL,  1246 DNR,  1246 DFL, or  1246 DFR, termed a doubles SLA area part, lies fully along doubles sideline part  1232 DNL,  1232 DNR,  1232 DFL, or  1232 DFR. OB portions  1246  form a rectangular annular composite VC doubles OB area portion  1246 T in which doubles SLA parts  1246 DNL and  1246 DFL or  1246 DNR and  1246 DFR are continuous and in line with each other. 
     Each straight area part of each of VC court area portions  1240 ,  1242 ,  1244 , and  1246  embodies one or more units of SF zone  112  or  912  (of one or more units of VC region  106  or  906 ) in the pentad units of color regions  108 ,  106 ,  886 ,  906 , and  908 . It is immaterial whether each such embodiment is performed with one or more units of zone  112  or with one or more units of zone  912  because reference symbols “ 112 ” and “ 912 ” are arbitrary designators and do not affect the substance of the embodiments. For simplicity, each pentad of regions  108 ,  106 ,  886 ,  906 , and  908  is hereafter treated as a pentad of consecutively adjoining regions  108 ,  106 ,  886 ,  106 , and  108 . Each pair of adjoining regions  106  and  108  are described as associated regions. As needed to distinguish the two units of VC region  106  in each pentad, one of them is denominated the “principal” (or “PP”) VC region while the other is denominated the “further” (or “FR”) VC region otherwise identified with reference symbol  906 . As needed to distinguish the two units of FC region  108  in each pentad, region  108  adjoining “principal” region  106  is denominated the “secondary” FC region while FC region  108  adjoining “further” region  106  is denominated the “ancillary” FC region otherwise identified with reference symbol  908 . 
     Similarly, color SF zones  114 ,  112 ,  892 ,  912 , and  914  in each region pentad are hereafter treated as consecutively adjoining zones  114 ,  112 ,  892 ,  112 , and  114 . Each pair of adjoining zones  112  and  114  are described as associated color SF zones. As needed to distinguish the two units of VC zone  112  in each pentad, zone  112  of “principal” VC region  106  is denominated the “principal” VC SF zone while zone  112  of “further” region  106  is denominated the “further” VC SF zone otherwise identified with reference symbol  912 . As needed to distinguish the two units of FC zone  114 , zone  114  of “secondary” FC region  108  is denominated the “secondary” FC SF zone while zone  114  of “ancillary” region  108  is denominated the “ancillary” FC SF zone otherwise identified with reference symbol  914 . Using this transformation, each straight part of each of VC court portions  1240 ,  1242 ,  1244 , and  1246  embodies an even number of two or more units of zone  112  (of one or more units of region  106 ) in the pentad units of color regions  108 ,  106 ,  886 ,  106 , and  108 . For four or more units of zone  112 , a straight part of any portion  1240 ,  1242 ,  1244 , or  1246  is allocated into multiple straight segments, each embodying two units of zone  112  in a different one of the pentad units. 
     Each VC court portion  1240 ,  1242 ,  1244 , or  1246  is usually of uniform color, termed normal-state LA color, across that portion  1240 ,  1242 ,  1244 , or  1246  during the normal state. PP color A for SF zone  112  of each pentad unit having zone  112  formed with a straight part, including a straight segment of such a straight part, of each portion  1240 ,  1242 ,  1244 , or  1246  is then usually its normal-state LA color. There may be multiple normal-state LA colors. 
     Changed color X for print area  118  of SF zone  112  of each pentad unit having zone  112  formed with a straight part, including a straight segment of such a straight part, of each VC court portion  1240 ,  1242 ,  1244 , or  1246  is a changed-state LA color for that portion  1240 ,  1242 ,  1244 , or  1246 . There may be multiple changed-state LA colors. 
     VC region  886  is sometimes embodied differently in some pentad units than in other pentad units usually provided that parts  1232 , or/and straight segments of parts  1232 , forming each pair of lines  28 ,  30 ,  34 , or  46  are embodied the same. In other words, each line part  1232  may selectively embody each of its one or more units of SF zone  892  in its one or more pentad units differently using a different unit of region  886  than zone  892  in each other pentad unit usually provided that the overall embodiment of the units of region  886  is symmetrical about the court&#39;s longitudinal and transverse axes. Since AD color B for zone  892  is the same for every pentad unit, this situation usually arises when non-color court characteristics, such as the AD basic TH impact criteria, vary across VC line area  1232 T. 
     The two units of VC region  106  in a pentad unit are sometimes embodied differently in some pentad units than in other pentad units. The different embodiments of the units of region  106  usually arise when court characteristics, such as normal-state LA color, changed-state LA color, and the PP TH impact characteristics, vary across VC court portions  1240 ,  1242 ,  1244 , and  1246 . The embodiments of the units of region  106  are usually symmetrical about the court&#39;s longitudinal and transverse axes for variations in the PP TH impact characteristics across portions  1240 ,  1242 ,  1244 , and  1246 . 
     The part of each servicecourt  38 NL,  38 NR,  38 FL, or  38 FR beyond its VC SC portion  1240 NL,  1240 NR,  1240 FL, or  1240 FR is a rectangular remainder individual FC IB SC area part  1250 NL,  1250 NR,  1250 FL, or  1250 FR extending directly along LA SC parts  1240 ANL,  1240 SNL, and  1240 CNL,  1240 ANR,  1240 SNR, and  1240 CNR,  1240 AFL,  1240 SFL, and  1240 CFL, or  1240 AFR,  1240 SFR, and  1240 CFR. FC SC parts  1250 NL and  1250 FL or  1250 NR or  1250 FR in each pair of net-separated servicecourts  38 NL and  38 FL or  38 NR and  38 FR form a rectangular composite FC IB SC area portion  1250 L or  1250 R fully directly surrounded by composite SC portion  1240 L or  1240 R. The part of each backcourt  40 N or  40 F beyond its annular VC BC portion  1242 N or  1242 F is a rectangular remainder individual FC IB BC area part  1252 N or  1252 F fully directly surrounded by BC portion  1242 N or  1242 F. 
     The part of each half alley  48 NL,  48 NR.  48 FL, or  48 FR beyond its VC HA portion  1244 NL,  1244 NR,  1244 FL, or  1244 FR is a rectangular remainder individual FC doubles HA area part  1254 NL,  1254 NR,  1254 FL, or  1254 FR extending directly along LA HA  1244 DNL,  1244 ENL, and  1244 QNL,  1244 DNR,  1244 ENR, and  1244 QNR,  1244 DFL,  1244 EFL, and  1244 QFL, or  1244 DFR,  1244 EFR, and  1244 QFR. FC HA parts  1254 NL and  1254 FL or  1254 NR and  1254 FR in each pair of net-separated half alleys  48 NL and  48 FL or  48 NR and  48 FR form a rectangular composite FC IB alley area portion  1254 L or  1254 R fully directly surrounded by composite HA portion  1244 L or  1244 R. The part of OB area  44  beyond VC OB portions  1246  is a rectangular annular remainder FC doubles OB area part  1256  which fully directly surrounds portions  1246 . Each FC part  1250 NL,  1250 NR,  1250 FL,  1250 FR,  1252 N,  1252 F,  1254 NL,  1254 NR,  1254 FL,  1254 FR, or  1256  is spaced apart from VC line area  1232 T. 
     Each of FC SC parts  1250 NL,  1250 NR,  1250 FL, and  1250 FR (collectively “ 1250 ”), FC BC parts  1252 N and  1252 F (collectively “ 1252 ”), FC HA parts  1254 NL,  1254 NR,  1254 FL, and  1254 FR (collectively “ 1254 ”), and FC doubles OB part  1256  embodies a unit of SF zone  114  (of FC region  108 ) in at least three pentad units. For example, each BC part  1252 N or  1252 F usually embodies four units of zone  114  in four pentad units respectively containing four units of SF zone  112  of BC parts  1242 EN,  1242 SN,  1242 BNL, and  1242 BNR or  1242 EF,  1242 SF,  1242 BFL, and  1242 BFR and preferably embodies six units of zone  114  in six pentad units respectively containing six units of zone  112  of BC parts  1242 EN,  1242 SNL,  1242 SNC,  1242 SNR,  1242 BNL, and  1242 BNR or  1242 EF,  1242 SFL,  1242 SFC,  1242 SFR,  1242 BFL, and  1242 BFR. 
     Each FC court part  1250 ,  1252 , or  1254  is usually of uniform fixed color across that part  1250 ,  1252 , or  1254 . Secondary color A′ for SF zone  114  of each pentad unit having zone  114  formed with a part  1250 ,  1252 , or  1254  is usually largely its fixed color. FC doubles OB part  1256  is usually of uniform fixed color at least along its entire (or full) interface with each VC OB portion  1246 . Color A′ for zone  114  of each pentad unit having zone  114  formed with OB part  1256  is usually largely its fixed color at least along its entire interface with each OB portion  1246 . There may be multiple such fixed colors. 
     VC line area  1232 T encompassing all lines  28 ,  30 ,  34 ,  36 , and  46  is usually uniformly a single color, termed the normal-state line color and preferably white or close to white, during the normal state consistent with tennis rules. Since part of line area  1232 T embodies SF zone  892  in each pentad unit, AD color B for zone  892  in each pentad unit is usually the same color, preferably white or close to white, in all the pentad units. Altered color Y for print area  898  in each pentad unit is usually uniformly a single color, materially different from color B, in all the pentad units. Color Y, termed the changed-state line color, can nonetheless variously differ from pentad unit to pentad unit. 
     PP normal-state LA color A for each VC SF zone  112  in each pentad unit is usually the same as secondary color A′ for associated FC SF zone  114  in that pentad unit. Color A for VC court portion  1240 ,  1242 , or  1244  in each court area  38 ,  40 , or  48 H is usually largely the fixed color of its FC part  1250 ,  1252 , or  1254  so that each court area  38 ,  40 , or  48 H is usually uniformly a single color during the normal state. Color A for VC OB portion  1246  is usually largely the fixed color of FC OB part  1256  at least along its entire interface with each OB portion  1246  so that doubles OB area  44  is usually uniformly a single color extending from the perimeter of IB area  42  through portions  1246  into OB part  1256  during the normal state. 
     Per the court color specifications presented near the beginning of this section, PP normal-state LA color A for each SF zone  112  in each pentad unit contrasts to, and thus differs significantly from, AD normal-state line color B for VC line area  1232 T whose parts  1232  or/and straight segments of parts  1232  embody SF zones  892  in the pentad units. Color A for zone  112  in each pentad unit selectively differs from, i.e., significantly differs from or is the same as on a selective basis, color A for zone  112  in one or more other pentad units. In particular, color A for zone  112  in one or more pentad units having zone  112  formed with a straight part, or a straight segment of a straight part, of any of VC court portions  1240 ,  1242 ,  1244 , and  1246  can differ from color A for zone  112  in one or more other pentad units having zone  112  formed with a straight part, or a straight segment of a straight part, of any of portions  1240 ,  1242 ,  1244 , and  1246 . The pentad units in IP structure  1230  can thus have multiple PP colors A. These colors can be designated as first PP color A, second PP color A, and so on up to the total number of colors A. If there are multiple changed colors X respectively corresponding to two or more of multiple colors A, the multiple colors X can be designated as first changed color X, second changed color X, and so on. 
     Other color designations can be employed. Since the VC portions of court areas  38 NL,  38 NR,  38 FL,  38 FR,  40 N,  40 F,  48 NL,  48 NR,  49 FL,  48 FR, and  44  in IP structure  1230  can potentially be of different colors during the normal state, thirty-four color court-descriptive designations of the type shown in Table 3 can be used where the parenthetical “≃” means largely the same as. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 3 
               
               
                   
               
               
                   
                   
                   
                 Changed 
               
               
                   
                 Fixed 
                 Principal 
                 (Changed- 
               
               
                   
                 Secondary 
                 (Normal- 
                 state) Color 
               
               
                   
                 Color A′ 
                 state) Color 
                 X of Print 
               
               
                   
                 of FC 
                 A of VC 
                 Area of VC 
               
               
                 Court Area 
                 Area Part 
                 Area Portion 
                 Area Portion 
               
               
                   
               
             
            
               
                 Near left servicecourt 38NL 
                 FSNL 
                 ASNL (≃FSNL) 
                 XSNL 
               
               
                 Near right servicecourt 
                 FSNR 
                 ASNR (≃FSNR) 
                 XSNR 
               
               
                 38NR 
               
               
                 Far left servicecourt 38FL 
                 FSFL 
                 ASFL (≃FSFL) 
                 XSFL 
               
               
                 Far right servicecourt 38FR 
                 FSFR 
                 ASFR (≃FSFR) 
                 XSFR 
               
               
                 Near backcourt 40N 
                 FBN 
                 ABN (≃FBN) 
                 XBN 
               
               
                 Far backcourt 40F 
                 FBF 
                 ABF (≃FBF) 
                 XBF 
               
               
                 Near left half alley 48NL 
                 FHNL 
                 AHNL (≃FHNL) 
                 XHNL 
               
               
                 Near right half alley 48NR 
                 FHNR 
                 AHNR (≃FHNR) 
                 XHNR 
               
               
                 Far left half alley 48FL 
                 FHFL 
                 AHFL (≃FHFL) 
                 XHFL 
               
               
                 Far right half alley 48FR 
                 FHFR 
                 AHFR (≃FHFR) 
                 XHFR 
               
               
                 OB area 44 along the part 
                 FOB 
                 AOB (≃FOB) 
                 XOBN 
               
               
                 of the perimeter of IB area 
               
               
                 42 in the near half court 
               
               
                 OB area 44 along the part 
                 FOB 
                 AOB (≃FOB) 
                 XOBF 
               
               
                 of the perimeter of IB area 
               
               
                 42 in the far half court 
               
               
                   
               
            
           
         
       
     
     PP normal-state color A for the VC LA portion of each area  38 NL,  38 NR,  38 FL,  38 FR,  40 N,  40 F,  48 NL,  48 NR,  48 FL, or  48 FR is usually largely fixed secondary color A′ of that area&#39;s FC portion as indicated parenthetically in Table 3. The same applies to OB area  44  along largely the full perimeter of IB area  42  because VC doubles OB portions  1246  both adjoin FC doubles OB part  1256 . However, OB portions  1246  can have different changed colors X as indicated by colors XOBN and XOBF in Table 3. AD color B for VC line area  1232 T is designated as normal-state line color BL. Altered color Y for print area  898  in each unit of AD VC region  886  in line area  1232 T is designated as changed-state line color YL. 
     A ball impacting an appropriate tennis line is “in”. The area critical to determining whether a ball is “in” or “out” is an area along the “outside” edge of each tennis line. The outside edge of each line  28 ,  30 ,  34 , or  46  is the edge furthest from the center of the court. Either edge of centerline  36  constitutes its outside edge depending on where tennis service originates. 
     In view of the preceding, SVLA BC parts  1242 SN and  1242 SF (collectively “ 1242 S”) are usually wider than SVLA SC parts  1240 SNL,  1240 SNR,  1240 SFL, and  1240 SFR (collectively “ 1240 S”), e.g., by amounts of at least the widths of servicelines  34 . Singles SLA HA parts  1244 QNL,  1244 QNR,  1244 QFL, and  1244 QFR (collectively “ 1244 Q”) are usually wider than singles SLA SC parts  1240 ANL,  1240 ANR,  1240 AFL, and  1240 AFR (collectively “ 1240 A”) and singles SLA BC parts  1242 BNL,  1242 BNR,  1242 BFL, and  1242 BFR (collectively “ 1242 B”), e.g., by amounts of at least the widths of singles sidelines  30 . OB BLA parts  1246 EN and  1246 EF (collectively “ 1246 E”) are usually wider than BLA BC parts  1242 EN and  1242 EF (collectively “ 1242 E”) and BLA HA parts  1244 ENL,  1244 ENR,  1244 EFL, and  1244 EFR (collectively “ 1244 E”), e.g., by amounts of at least the widths of baselines  28 . Doubles OB SLA parts  1246 DNL,  1246 DNR,  1246 DFL, and  1246 DFR (collectively “ 1246 D”) are usually wider than doubles SLA HA parts  1244 DNL,  1244 DNR,  1244 DFL, and  1244 DFR (collectively “ 1244 D”), e.g., by amounts of at least the widths of doubles sidelines  46 . CLA SC parts  1240 CNL,  1240 CNR,  1240 CFL, and  1240 CFR (collectively “ 1240 C”) are usually of approximately the same width. 
     Taking note that tennis lines are usually 5 cm wide with baselines being 5-10 cm wide, commonly 10 cm wide, wider SVLA BC parts  1242 S, wider singles SLA HA parts  1244 Q, and wider doubles OB SLA parts  1246 D are usually at least 10 cm, preferably at least 15 cm, more preferably at least 20 cm, wide. Wider OB BLA parts  1246 E and CLA SC parts  1240 C are usually at least 15 cm, preferably at least 20 cm, more preferably at least 25 cm, wide. Narrower SVLA SC parts  1240 S, narrower singles SLA SC parts  1240 A, narrower singles SLA BC parts  1242 B, narrower doubles SLA HA parts  1244 D, narrower BLA BC parts  1242 E, and narrower BLA HA parts  1244 E are correspondingly usually at least 5 cm, preferably at least 10 cm, more preferably at least 15 cm, wide. 
     Players competing in, and any officials used for, tennis matches usually can nearly always accurately directly visually determine, i.e., without using the present CC capability, whether balls impacting surface  102  more than 30 cm outside, or more than 25 cm inside, any of lines  30 ,  34 , and  46  are “in” or “out”. Accordingly, wider LA parts  1242 S,  1244 Q, and  1246 D are usually no more than 30 cm, preferably no more than 25 cm, wide. Narrower LA parts  1240 S,  1240 A,  1242 B,  1244 D,  1242 E, and  1244 E are correspondingly usually no more than 25 cm, preferably no more than 20 cm, wide. The players and any officials can usually nearly always accurately directly visually determine whether balls impacting surface  102  more than 35 cm outside baselines  28  are “in” or “out”. The same applies to served balls impacting surface  102  more than 35 cm away from centerline  36 . LA parts  1246 E and  1240 C are usually no more than 35 cm, preferably no more than 30 cm, wide. 
     Balls impacting on or close to sidelines  30  and  46  near net  32  tend to impact surface  102  with less force than balls impacting on or close to lines  30  and  46  farther away from net  32 . In light of this, the PP, AD, FR, and CP basic TH impact criteria can vary with distance from net  32  to require less force or pressure near net  32 , e.g., less than a quarter way from net  32  to baselines  28 , than farther away from net  32 , the FR basic TH impact criteria hereafter being replaced with PP basic TH impact criteria for the same reasons that color regions  906  and  908  in the pentad units are respectively replaced with color regions  106  and  108 . 
     IP structure  1230  is relatively expensive because it provides CC capability at and directly along both edges of the entire length of each line  28 ,  30 ,  34 ,  36 , or  46 . However, only a small fraction of balls impacting on or close to tennis lines usually impact the half of centerline  36  nearest net  32  during tennis service, the quarter of each singles sideline  30  nearest net  32  during singles, or the quarter of each doubles sideline  46  nearest net  32  during doubles. A less expensive implementation of the present tennis IP structure is achieved by omitting the CC capability along the foregoing parts of centerline  36  and sidelines  30  and  46 . Since the area critical to determining whether a ball impacting on or close to each line  28 ,  30 ,  34 , or  46  is “in” or “out” extends along its outside edge, a less expensive implementation is also achieved by omitting the CC capability along the inside edge of each line  28 ,  30 ,  34 , or  46 . 
       FIG. 97  illustrates a tennis IP structure  1260  consisting of net  32  and OI structures  880  and  900  or, preferably, cell-containing OI structures  1080  and  1100  incorporated in the foregoing way into a tennis court suitable for singles and doubles to form a tennis-playing structure having CC capability that assists in determining whether object  104  embodied with a ball impacting surface  102  in the immediate vicinity of a selected court line is “in” or “out”. For doubles, surface  102  again consists of OB area  44  and IB area  42  formed with servicecourts  38 NL,  38 NR,  38 FL, and  38 FR, backcourts  40 N and  40 F, half alleys  48 NL,  48 NR,  48 FL, and  48 FR, and court lines consisting of baselines  28 N and  28 F, singles sidelines  30 L and  30 R, servicelines  34 N and  34 F, centerline  36 , and doubles sidelines  46 L and  46 R all identified the same as in IP structure  1230 . 
     Portions of court lines  28 ,  30 ,  34 ,  36 , and  46  form a composite VC singles/doubles line area  1262 T consisting of near and far VC singles/doubles line area  1262 N and  1262 F respectively in the near and far half courts. Each VC singles/doubles line area  1262 N or  1262 F consists of twelve elongated straight continuous VC line area parts  1262 ENL,  1262 ENC,  1262 ENR,  1262 SNL,  1262 SNR,  1262 ANL,  1262 BNL,  1262 ANR,  1262 BNR,  1262 CN,  1262 DNL, and  1262 DNR or  1262 EFL,  1262 EFC,  1262 EFR,  1262 SFL,  1262 SFR,  1262 AFL,  1262 BFL,  1262 AFR,  1262 BFR,  1262 CF,  1262 DFL, and  1262 DFR (collectively “ 1262 ”). VC line parts  1262 ENL,  1262 ENC, and  1262 ENR respectively lying fully along the near ends of half alley  48 NL, backcourt  40 N, and half alley  48 NR form near baseline  28 N. VC line parts  1262 EFL,  1262 EFC, and  1262 EFR respectively lying fully along the far ends of half alley  48 FL, backcourt  40 F, and half alley  48 FR form far baseline  28 F. VC line parts  1262 SNL and  1262 SNR or  1262 SFL and  1262 SFR respectively lying fully along servicecourts  38 NL and  38 NR or  38 FL and  38 FR and jointly lying fully along backcourt  40 N or  40 F form serviceline  34 N or  34 F. 
     VC line part  1262 BNL or  1262 BFL lying between backcourt  40 N or  40 F and left half alley  48 NL or  48 FL forms the part of left singles sideline  30 L extending from baseline  28 N or  28 F to serviceline  34 N or  34 F. VC line part  1262 BNR or  1262 BFR lying between backcourt  40 N or  40 F and right half alley  48 NR or  48 FR forms the part of right singles sideline  30 R extending from baseline  28 N or  28 F to serviceline  34 N or  34 F. VC line part  1262 ANL or  1262 AFL lying between left servicecourt  38 NL or  38 FL and left half alley  48 NL or  48 FL forms a part of left singles sideline  30 L extending from serviceline  34 N or  34 F to a selected left singles sideline location situated between (or spaced apart from) line  34 N or  34 F and the net line. VC line part  1262 ANR or  1262 AFR lying between right servicecourt  38 NR or  38 FR and right half alley  48 NR or  48 FR forms a part of right singles sideline  30 R extending from serviceline  34 N or  34 F to a selected right singles sideline location situated between line  34 N or  34 F and the net line. Singles sideline parts  1262 ANL and  1262 BNL,  1262 ANR and  1262 BNR,  1262 AFL and  1262 BFL, or  1262 AFR and  1262 BFR form a straight VC QC singles sideline area part  1262 QNL,  1262 QNR,  1262 QFL, or  1262 QFR. 
     VC line part  1262 CN or  1262 CF lying between servicecourts  38 NL and  38 NR or  38 FL and  38 FR forms a part of centerline  36  extending from serviceline  34 N or  34 F to a selected centerline location situated between line  34 N or  34 F and the net line. VC line part  1262 DNL or  1262 DFL lying between left half alley  48 NL or  48 FL and doubles OB area  44  forms a part of left doubles sideline  46 L extending from baseline  28 N or  28 F to a selected left doubles sideline location situated between line  28 N or  28 F and the net line. VC line part  1262 DNR or  1262 DFR lying between right half alley  48 NR or  48 FR and OB area  44  forms a part of right doubles sideline  46 R extending from baseline  28 N or  28 F to a selected right doubles sideline location situated between line  28 N or  28 F and the net line. 
     The selected singles sideline, centerline, and doubles sideline locations in each half court are usually from one fourth to three fourths of the distance from the imaginary extended serviceline in that half court to the net line. VC line area  1262 T is spaced apart from the net line. Each individual VC line area  1262 N or  1262 F in the example of  FIG. 97  consists of baseline  28 N or  28 F, associated serviceline  34 N or  34 F, approximately the three eighths of sidelines  30  and  46  extending from baseline  28 N or  28 F toward the net line, and approximately the one fourth of centerline  36  extending from serviceline  34 N or  34 F toward the net line. Line area  1262 T is usually symmetrical about the court&#39;s longitudinal and transverse axes. 
     The remainders of sidelines  30  and  46  and centerline  36  form an FC singles/doubles line area  1264 T consisting of near and far FC singles/doubles line areas  1264 N and  1264 F respectively in the near and far half courts. Each FC singles/doubles line area  1264 N or  1264 F consists of five elongated straight continuous individual FC line area parts  1264 ANL,  1264 ANR,  1264 CN,  1264 DNL, and  1264 DNR or  1264 AFL,  1264 AFR,  1264 CF,  1264 DFL, and  1264 DFR. Line parts  1264 ANL and  1264 AFL or  1264 ANR and  1264 AFR form a continuous straight composite FC line area part  1264 AL or  1264 AR constituting the remainder of singles sideline  30 L or  30 R. Line parts  1264 CN and  1264 CF form a continuous straight composite FC line area part  1264 C constituting the remainder of centerline  36 . Line parts  1264 DNL and  1264 DFL or  1264 DNR and  1264 DFR form a continuous straight composite FC line area part  1264 DL or  1264 DR constituting the remainder of doubles sideline  46 L or  46 R. 
     Each VC line area part  1262  embodies one or more units of SF zone  892  (of one or more units of VC region  886 ) in a plurality of larger units of a specified one of OI structures  880  and  1080  or  900  and  1100 . In the multiple-unit situation, a line part  1262  is allocated into multiple straight VC area segments, each embodying a unit of zone  892  in a different one of the larger units. AD color B for zone  892  in each larger unit is the color of VC line area  1262 T during the normal state and, as dealt with below, is usually the same in every larger unit. Inasmuch as line area  1262 T and FC line area  1264 T form the total line area consisting of lines  28 ,  30 ,  34 ,  36 , and  46 , the fixed color of line area  1264 T is usually largely color B. 
     Each larger unit containing baseline part  1262 ENL,  1262 ENC,  1262 ENR,  1262 EFL,  1262 EFC, or  1262 EFR, serviceline part  1262 SNL,  1262 SNR,  1262 SFL, or  1262 SFR, sideline part  1262 BNL,  1262 BNR,  1262 BFL, or  1262 BFR, or a straight segment of any of these line parts, is a tetrad of color regions  108 ,  106 ,  886 , and  888  for which subordinate FC region  888  appears solely as single subordinate color B′ along subordinate SF zone  894  in that tetrad unit. If sideline part  1262 ANL,  1262 ANR,  1262 AFL,  1262 AFR,  1262 DNL,  1262 DNR,  1262 DFL, or  1262 DFR is allocated into multiple straight segments, this also applies to each segment spaced apart from FC line area  1264 T. Each of these tetrad units constitutes a single-sub tetrad unit where “sub” means subordinate. 
     A larger unit containing sideline part  1262 ANL,  1262 ANR,  1262 AFL,  1262 AFR,  1262 DNL,  1262 DNR,  1262 DFL, or  1262 DFR when it is not allocated into multiple straight segments is a tetrad of color regions  108 ,  106 ,  886 , and  888  for which subordinate FC region  888  consists of two subordinate FC subregions respectively appearing as two different subordinate colors B′ along two respective subordinate FC SF subzones of subordinate SF zone  894  in that tetrad unit. If sideline part  1262 ANL,  1262 ANR,  1262 AFL,  1262 AFR,  1262 DNL,  1262 DNR,  1262 DFL, or  1262 DFR is allocated into multiple straight segments, the same applies to the segment adjoining FC line area  1264 T. Each of these tetrad units constitutes a double-sub tetrad unit, “sub” again meaning subordinate. The single-sub and double-sub tetrad units provide the same CC capability because they differ only in regard to the constituency of an FC region, namely region  888 . 
     Subordinate color B′ of FC SF zone  894  in each single-sub tetrad unit is termed FC non-line subordinate color B′ because it is the color of FC court area beyond FC line area  1264 T. Subordinate color B′ of one of the subzones of zone  894  in each double sub tetrad unit is likewise termed FC non-line subordinate color B′ because it also is the color of FC court area beyond line area  1264 T. Subordinate color B′ of other of the subzones of zone  894  in each double sub tetrad unit is termed FC line subordinate color B′ because it is the color of area  1264 T. Since area  1264 T is usually largely color B, FC line subordinate color B′ is usually largely color B. 
     Each larger unit containing one of centerline parts  1262 CN and  1262 CF (collectively “ 1262 C”) when it is not allocated into multiple straight segments is a hexad of color regions  108 ,  106 ,  886 ,  888 ,  906 , and  908  for which FC region  888  consists of straight part  1264 C of FC line area  1264 T at centerline  36 . For the reasons presented above in regard to the pentad units in IP structure  1230 , each hexad unit of regions  108 ,  106 ,  886 ,  888 ,  906 , and  908  is hereafter treated as a hexad unit of regions  108 ,  106 ,  886 ,  888 ,  106 , and  108  respectively having SF zones  114 ,  112 ,  892 ,  894 ,  112 , and  114 . The above-described procedure for distinguishing the two units of VC region  106 , or their two zones  112 , for each pentad unit is used as necessary for each hexad unit of regions  108 ,  106 ,  886 ,  888 ,  106 , and  108 . 
     If a centerline part  1262 C is allocated into multiple straight segments, a larger unit containing the segment adjoining FC line area  1264 T is a hexad of color regions  108 ,  106 ,  886 ,  888 ,  106 , and  108  for which FC region  888  again consists of FC centerline part  1264 C whereas a larger unit containing each segment spaced apart from line area  1264 T is a pentad of color regions  108 ,  106 ,  886 ,  906 , and  908  hereafter treated as a pentad of regions  108 ,  106 ,  886 ,  106 , and  108  as described above for IP structure  1230 . Subordinate color B′ of SF zone  894  of region  888  in each hexad unit is termed FC line subordinate color B′ because it is largely AD color B of centerline part  1264 C embodying that unit of zone  894 . The hexad and pentad units provide the same CC capability because they differ only in regard to the presence/absence of an FC region, again region  888 . The hexad and pentad units are sometimes together termed hexad/pentad units. 
     Each near servicecourt  38 NL or  38 NR is partly occupied with an elongated straight near VC IB CLA SC area portion (or part)  1270 NL or  1270 NR lying fully along near centerline part  1262 CN so as to end at its selected centerline location. Each far servicecourt  38 FL or  38 FR is partly occupied with an elongated straight far VC IB CLA SC area portion (or part)  1270 FL or  1270 FR lying fully along far centerline part  1262 CF so as to end at its selected centerline location. VC SC portions  1270 NL,  1270 NR,  1270 FL, and  1270 FR (collectively “ 1270 ”) are usually mirror images about the court&#39;s longitudinal and transverse axes. 
     Each backcourt  40 N or  40 F is partly occupied with an elongated straight full VC IB SVLA BC area portion (or part)  1272 N or  1272 F lying fully along (closest) serviceline  34 N or  34 F so as to end at singles sidelines  30 . VC BC portions  1272 N and  1272 F (collectively “ 1272 ”) are usually symmetrical about the court&#39;s longitudinal axis and mirror images about the court&#39;s transverse axis. 
     Each BC portion  1272 N or  1272 F consists of three elongated straight VC SVLA BC area parts  1272 SNL,  1272 SNC, and  1272 SNR or  1272 SFL,  1272 SFC, and  1272 SFR respectively termed left end, central, and right end area parts. Each central SVLA BC part  1272 SNC or  1272 SFC lies fully along the segments of serviceline parts  1262 SNL and  1262 SNR or  1262 SFL and  1262 SFR situated between imaginary extensions of the outside edges of CLA SC portions  1270  into backcourt  40 N or  40 F. Each end SVLA BC part  1272 SNL,  1272 SNR,  1272 SFL, or  1272 SFR lies fully along the remainder of serviceline part  1262 SNL,  1262 SNR,  1262 SFL, or  1262 SFR. 
     Each near half alley  48 NL or  48 NR is partly occupied with an elongated straight near VC IB singles SLA HA area portion (or part)  1274 NL or  1274 NR lying fully along parts  1262 BNL and  1262 ANL or  1262 BNR and  1262 ANR of (closest) singles sideline  30 L or  30 R so as to end at the selected singles sideline location of sideline part  1262 BNL or  1262 BNR. Each far half alley  48 FL or  48 FR is partly occupied with an elongated straight far VC IB singles SLA HA area portion (or part)  1274 FL or  1274 FR lying fully along parts  1262 BFL and  1262 AFL or  1262 BFR and  1262 AFR of (closest) singles sideline  30 L or  30 R so as to end at the selected singles sideline location of sideline part  1262 BFL or  1262 BFR. VC singles HA portions  1274 NL,  1274 NR,  1274 FL, and  1274 FR (collectively “ 1274 ”) are usually mirror images about the court&#39;s longitudinal and transverse axes. 
     Each HA portion  1274 NL,  1274 NR,  1274 FL, or  1274 FR consists of two elongated straight VC singles SLA HA area parts  1274 ANL and  1274 BNL,  1274 ANR and  1274 BNR,  1274 AFL and  1274 BFL, or  1274 AFR and  1274 BFR. Each left singles SLA HA part  1274 ANL or  1274 AFL lies fully along left sideline part  1262 ANL or  1262 AFL and the segment of left sideline part  1262 BNL or  1262 BFL situated between part  1262 ANL or  1262 AFL and an imaginary leftward extension of the outside edge of SVLA BC portion  1272 N or  1272 F. Each right singles SLA HA part  1274 ANR or  1274 AFR lies fully along right sideline part  1262 ANR or  1262 AFR and the segment of right sideline part  1262 BNR or  1262 BFR situated between part  1262 ANR or  1262 AFR and an imaginary rightward extension of the outside edge of BC portion  1272 N or  1272 F. Each other singles SLA HA part  1274 BNL,  1274 BNR,  1274 BFL, or  1274 BFR lies fully along the remainder of sideline part  1262 BNL,  1262 BNR,  1262 BFL, or  1262 BFR. 
     Doubles OB area  44  is partly occupied with two ␣-shaped individual VC doubles OB BLA area portions  1276 N and  1276 F on opposite sides of the net line so as to form a composite VC doubles OB area portion  1276 T. VC OB portions  1276 N and  1276 F (collectively “ 1276 ”) are usually symmetrical about the court&#39;s longitudinal axis and mirror images about the court&#39;s transverse axis. Each doubles OB portion  1276 N or  1276 F consists of five elongated straight VC doubles OB LA area parts  1276 DNL,  1276 ENL,  1276 ENC,  1276 ENR, and  1276 DNR or  1276 DFL,  1276 EFL,  1276 EFC,  1276 EFR, and  1276 DFR. Doubles OB part  1276 DNL,  1276 DFL,  1276 DNR, or  1276 DFR, termed a doubles SLA area part, lies fully along doubles sideline part  1262 DNL,  1262 DFL,  1262 DNR, or  1262 DFR so as to end at its selected doubles sideline location. 
     Doubles OB parts  1276 ENL,  1276 ENC, and  1276 ENR or  1276 EFL,  1276 EFC, and  1276 EFR, respectively termed left end, central, and right end area parts, are continuous and in line with one other to form a straight composite VC doubles OB BLA area part  1276 EN or  1276 EF. Central OB BLA part  1276 ENC or  1276 EFC lies fully along central baseline part  1262 ENC or  1262 EFC and the segments of end baseline parts  1262 ENL and  1262 ENR or  1262 EFL and  1262 EFR situated between part  1262 ENC or  1262 EFC and imaginary extensions of the outside edges of singles SLA HA parts  1274 BNL and  1274 BNR or  1274 BFL and  1274 BFR. Each end OB BLA part  1276 ENL,  1276 ENR,  1276 EFL, or  1276 EFR lies fully along the remainder of end baseline part  1262 ENL,  1262 ENR,  1262 EFL, or  1262 EFR. 
     Each VC SC portion  1270  embodies one or more units of VC SF zone  112  (of one or more units of VC region  106 ) in the hexad/pentad units. In the multiple-unit situation, an SC portion  1270  is allocated into multiple straight area segments, each embodying a unit of zone  112  in a different one of the hexad/pentad units. Each straight part of each of VC court portions  1272 ,  1274 , and  1276  embodies one or more units of zone  112  in the tetrad units. In this multiple-unit situation, a straight part of any court portion  1272 ,  1274 , or  1276  is allocated into multiple straight area segments, each embodying a unit of zone  112  in a different one of the tetrad units. 
     Each VC court portion  1270 ,  1272 ,  1274 , or  1276  is usually of uniform color, termed normal-state LA color, across that portion  1270 ,  1272 ,  1274 , or  1276  during the normal state. PP Color A for SF zone  112  of each hexad/pentad unit in each SC portion  1270  is then usually its normal-state LA color. Color A for zone  112  of each tetrad unit in each court portion  1272 ,  1274 , or  1276  is usually its normal-state LA color. Also, OB portions  1276  are usually the same color during the normal state so that color A is usually the same for zone  112  of every tetrad unit in portions  1276 . IP structure  1260  may have multiple normal-state LA colors. 
     Changed color X for print area  118  of SF zone  112  of each hexad/pentad unit in each SC portion  1270  is a changed-state LA color of that SC portion  1270 . Color X for area  118  of zone  112  of each tetrad unit in each court portion  1272 ,  1274 , or  1276  is a changed-state LA color of that portion  1272 ,  1274 , or  1276 . Color X is usually the same for area  118  of zone  112  of every tetrad unit in OB portions  1276 . IP structure  1260  may have multiple changed-state LA colors. 
     The tetrad and hexad/pentad units are collectively termed “polyad units”. Subject to changing VC line area  1232 T to VC line area  1262 T, VC region  886  is sometimes embodied differently in some polyad units than in other polyad units in the same way that region  886  in IP structure  1230  is sometimes embodied differently in some pentad units than in other pentad units. Subject to changing VC court portions  1240 ,  1242 ,  1244 , and  1246  respectively to VC court portions  1270 ,  1272 ,  1274 , and  1276 , the one or two units of VC region  106  in a polyad unit are sometimes embodied differently in some polyad units than in other polyad units in the same way that the two units of region  106  in a pentad unit in structure  1230  are sometimes embodied differently in some pentad units than in other pentad units. 
     The part of each servicecourt  38 NL,  38 NR,  38 FL, or  38 FR beyond its VC SC portion  1270 NL,  1270 NR,  1270 FL, or  1270 FR is a roughly rectangular remainder individual FC IB SC area part  1280 NL,  1280 NR,  1280 FL, or  1280 FR adjoining the entire outside edge of SC portion  1270 NL,  1270 NR,  1270 FL, or  1270 FR. FC SC parts  1280 NL and  1280 FL or  1280 NR and  1280 FR in each pair of net-separated servicecourts  38 NL and  38 FL or  38 NR and  38 FR form a continuous roughly rectangular composite FC IB SC area portion  1280 L or  1280 R. The part of each backcourt  40 N or  40 F beyond its VC BC portion  1272 N or  1272 F is a rectangular remainder individual FC IB BC area part  1282 N or  1282 F adjoining the entire outside edge of BC portion  1272 N or  1272 F. 
     The part of each half alley  48 NL,  48 NR.  48 FL, or  48 FR beyond its VC HA portion  1274 NL,  1274 NR,  1274 FL, or  1274 FR is a roughly rectangular remainder individual FC doubles IB HA area part  1284 NL,  1284 NR,  1284 FL, or  1284 FR adjoining the entire outside edge of HA portion  1274 NL,  1274 NR,  1274 FL, or  1274 FR. FC doubles IB HA parts  1284 NL and  1284 FL or  1284 NR and  1284 FR in each pair of net-separated half alleys  48 NL and  48 FL or  48 NR and  48 FR form a continuous roughly rectangular FC doubles IB alley area portion  1284 L or  1284 R. The part of OB area  44  beyond VC OB portions  1276  is a roughly rectangular annular remainder FC doubles OB area part  1286  fully adjoining the outside edges of portions  1276 . 
     Each FC SC part  1280 NL,  1280 NR,  1280 FL, or  1280 FR embodies a unit of FC SF zone  894  (of FC region  888 ) in at least one single-sub tetrad unit (lying along serviceline part  1262 SNL,  1262 SNR,  1262 SFL, or  1262 SFR and potentially along at least one straight segment of singles sideline part  1262 ANL,  1262 ANR,  1262 AFL, or  1262 AFR spaced apart from FC singles sideline part  1264 ANL,  1264 ANR,  1264 AFL, or  1264 AFR) and partly in at least one double-sub tetrad unit (lying either along part  1262 ANL,  1262 ANR,  1262 AFL, or  1262 AFR or along a straight segment of part  1262 ANL,  1262 ANR,  1262 AFL, or  1262 AFR adjoining part  1264 ANL,  1264 ANR,  1264 AFL, or  1264 AFR) as well as embodying a unit of FC SF zone  114  (of FC region  108 ) in at least one hexad unit (lying either along a centerline part  1262 C or along a straight segment of a part  1262 C adjoining FC centerline part  1264 C). If VC SC portion  1270 NL,  1270 FL,  1270 NR, or  1270 FR is allocated into multiple straight segments, each FC SC part  1280 NL,  1280 NR,  1280 FL, or  1280 FR also embodies a unit of zone  114  in at least one pentad unit (lying along a straight segment of a part  1262 C spaced apart from part  1264 C). 
     Each FC BC part  1282 N or  1282 F embodies a unit of SF zone  114  in at least two single-sub tetrad units (lying along serviceline parts  1262 SNL and  1262 SNR or  1262 SFL and  1262 SFR) and a unit of SF zone  894  in at least three single-sub tetrad units (lying along baseline part  1262 BN or  1262 BF and singles sideline parts  1262 BNL and  1262 BNR or  1262 BFL and  1262 BFR). 
     Each FC HA part  1284 NL,  1284 NR,  1284 FL, or  1284 FR embodies a unit of SF zone  114  in at least one single-sub tetrad unit (lying along singles sideline part  1262 BNL,  1262 BNR,  1262 BFL, or  1262 BFR and potentially along at least one straight segment of singles sideline part  1262 ANL,  1262 ANR,  1262 AFL, or  1262 AFR spaced apart from FC singles sideline part  1264 ANL,  1264 ANR,  1264 AFL, or  1264 AFR) and in at least one double-sub tetrad unit (lying either along part  1262 ANL,  1262 ANR,  1262 AFL, or  1262 AFR or along a straight segment of part  1262 ANL,  1262 ANR,  1262 AFL, or  1262 AFR adjoining FC part  1264 ANL,  1264 ANR,  1264 AFL, or  1264 AFR) as well as embodying a unit of SF zone  894  in at least one single-sub tetrad unit (lying along baseline part  1262 ENL,  1262 ENR,  1262 EFL, or  1262 EFR and potentially along at least one straight segment of doubles sideline part  1262 DNL,  1262 DNR,  1262 DFL, or  1262 DFR spaced apart from FC doubles sideline part  1264 DNL,  1264 DNR,  1264 DFL, or  1264 DFR) and partly in at least one double-sub tetrad unit (lying either along part  1262 DNL,  1262 DNR,  1262 DFL, or  1262 DFR or along a straight segment of part  1262 DNL,  1262 DNR,  1262 DFL, and  1262 DFR adjoining FC part  1264 DNL,  1264 DNR,  1264 DFL, or  1264 DFR). 
     FC doubles OB part  1286  embodies a unit of SF zone  114  in at least six single-sub tetrad units (lying along baseline parts  1262 ENL,  1262 ENC,  1262 ENR,  1262 EFL,  1262 EFC, and  1262 EFR and potentially along straight segments of doubles sideline parts  1262 DNL,  1262 DNR,  1262 DFL, and  1262 DFR respectively spaced apart from FC doubles sideline parts  1264 DNL,  1264 DNR,  1264 DFL, and  1264 DFR) and partly in at least four double-sub tetrad units (lying either along parts  1262 DNL,  1262 DNR,  1262 DFL, and  1262 DFR or along straight segments of parts  1262 DNL,  1262 DNR,  1262 DFL, and  1262 DFR respectively adjoining FC parts  1264 DNL,  1264 DNR,  1264 DFL, and  1264 DFR). 
     More particularly, the two subzones of SF zone  894  in each double-sub tetrad unit are respectively embodied with (i) FC SC part  1280 NL,  1280 NR,  1280 FL, or  1280 FR and FC singles sideline part  1264 ANL,  1264 ANR,  1264 AFL, or  1264 AFR or with (ii) FC alley part  1284 NL,  1284 NR,  1284 FL, or  1284 FR and FC doubles sideline part  1264 DNL,  1264 DNR,  1264 DFL, or  1264 DFR. The two SF zones  114  in each hexad/pentad unit are respectively embodied with FC SC parts  1280 NL and  1280 NR or  1280 FL and  1280 FR. Also, zones  114  and  894  in each single-sub tetrad unit are variously respectively embodied with the two parts of one of a plurality of different pairs of different ones of FC SC parts  1280 NL,  1280 NR,  1280 FL, and  1280 FR (collectively “ 1280 ”), FC BC parts  1282 N and  1282 F (collectively “ 1282 ”), FC HA parts  1284 NL,  1284 NR,  1284 FL, and  1284 FR (collectively “ 1284 ”), and FC doubles OB part  1286 . The pairs consist of (a) either SC part  1280  and associated (closest) BC part  1282 , (b) either SC part  1280  and closest HA part  1284 , (c) either BC part  1282  and either associated (closest) HA part  1284 , (d) either BC part  1282  and OB part  1286 , and (e) either HA part  1284  and OB part  1286 . 
     Each FC court part  1280 ,  1282 , or  1284  is usually of uniform fixed color across that part  1280 ,  1282 , or  1284 . Consequently, FC non-line subordinate color B′ for SF zone  894  of each single-sub tetrad unit having zone  894  formed with a court part  1280  or  1284  is usually largely its fixed color. FC non-line subordinate color B′ for the subzone of zone  894  of each double-sub tetrad unit having that subzone formed with a court part  1280  or  1284  is also usually largely its fixed color. FC line subordinate color B′ for the subzone of zone  894  of each double-sub tetrad unit having that subzone formed with one of FC sideline parts  1264 ANL,  1264 ANR,  1264 AFL, and  1264 AFR (collectively “ 1264 A”) or  1264 DNL,  1264 DNR,  1264 DFL, and  1264 DFR (collectively “ 1264 D”) is usually largely color B. FC line subordinate color B′ for zone  894  of each hexad unit having SF zone  114  formed with an SC part  1280  is usually largely color B. 
     Secondary color A′ for SF zone  114  of each hexad/pentad unit having zone  114  formed with an SC part  1280  is usually largely its fixed color. Color A′ or FC non-line subordinate color B′ for SF zone  114  or  894  of each single-sub tetrad unit having zone  114  or  894  formed with a BC part  1282  is usually largely its fixed color. Color A′ for zone  114  of each single-sub tetrad unit having zone  114  formed with an HA part  1284  is usually largely its fixed color. Doubles OB part  1286  is usually of uniform fixed color at least along its entire interface with each VC OB portion  1276 . Color A′ for zone  114  of each of the tetrad units, i.e., both single-sub and double-sub tetrad units, having zone  114  formed with OB part  1286  is usually largely its fixed color at least along its entire interface with each VC OB portion  1276 . IP structure  1260  may have multiple such fixed colors. 
     VC line area  1262 T is usually uniformly a single color, the normal-state line color preferably white or nearly white, during the normal state consistent with tennis rules. Since part of line area  1262 T embodies SF zone  892  in each polyad unit, AD color B for zone  892  in each polyad unit is usually the same color, preferably white or close to white, in all the polyad units. This also applies to color B′ of FC line area  1264 T. Altered color Y for print area  898  of zone  892  in each polyad unit is usually uniformly a single color, the changed-state line color materially different from color B, in all the polyad units. Color Y can nonetheless variously differ from polyad unit to polyad unit. 
     PP normal-state color A for each VC SF zone  112  in each polyad unit is usually the same as secondary color A′ for associated FC SF zone  114  in that polyad unit. Color A for VC portion  1270 ,  1272 , or  1274  in each court area  38 ,  40 , or  48 H is usually largely the fixed color of its FC part  1280 ,  1282 , or  1284  so that each court area  38 ,  40 , or  48 H is usually uniformly a single color during the normal state. Color A for VC OB portion  1276  is usually uniformly largely the fixed color of FC OB part  1286  at least along its entire interfaces with OB portions  1276 . 
     Per the above-described court color specifications, PP normal-state LA color A for each SF zone  112  in each polyad unit contrasts to, and thus differs significantly from, AD normal-state line color B for VC line area  1262 T whose parts  1262  or/and straight segments of parts  1262  embody SF zones  892  in the polyad units. Color A for each zone  112  in each polyad unit selectively differs from, i.e., significantly differs from or is the same on a selective basis as, color A for zone  112  in one or more other polyad units. Specifically, color A for each zone  112  in one or more polyad units having zone  112  formed with any of an SC portion  1270 , a straight segment of a portion  1270 , a straight part (described above) of any of court portions  1272 ,  1274 , and  1276 , and a straight segment of a straight part of any of portions  1272 ,  1274 , and  1276  can differ from color A for zone  112  in one or more other polyad units having zone  112  formed with any of a portion  1270 , a straight segment of a portion  1270 , a straight part of any of portions  1272 ,  1274 , and  1276 , and a straight segment of a straight part of any of portions  1272 ,  1274 , and  1276 . The polyad units in IP structure  1260  can have multiple PP colors A. These colors can be designated as first PP color A, second PP color A, and so on up to the total number of colors A. If there are multiple changed colors X respectively corresponding to two or more of multiple colors A, the multiple colors X can be designated as first changed color X, second changed color X, and so on. 
     Other color designations can be utilized. Since the VC portions of court areas  38 NL,  38 NR,  38 FL,  38 FR,  40 N,  40 F,  48 NL,  48 NR,  48 FL,  48 FR, and  44  in IP structure  1260  can potentially be of different colors during the normal state, structure  1260  can use thirty-four color court-descriptive designations of the type shown in Table 3 provided that the parenthetical color headings in Table 3 are used, at least for the fixed colors of the FC area parts, because the fixed colors are variously embodied with fixed secondary color A′ and non-line subordinate color B′. AD color B for line area  1262 T is designated as normal-state line color BL. Altered color Y for print area  898  in each unit of VC region  886  in line area  1262 T is designated as changed-state line color YL. The fixed color, usually largely color B, of FC line area  1264 T is designated as fixed line color FL. 
     SC portions  1270  and parts  1276 EN and  1276 EF (collectively “ 1276 E”) of OB portions  1276  along baselines  28  are usually at least 15 cm, preferably at least 20 cm, more preferably at least 25 cm, wide and are usually no more than 35 cm, preferably no more than 30 cm, wide. BC portions  1272 , HA portions  1274 , and parts  1276 DNL,  1276 DNR,  1276 DFL, and  1276 DFR (collectively “ 1276 D”) of OB portions  1276  along doubles sidelines  46  are usually at least 10 cm, preferably at least 15 cm, more preferably at least 20 cm, wide and are usually no more than 30 cm, preferably no more than 25 cm, wide. 
     Singles/doubles tennis IP structures  1230  and  1260  are considered largely together in the following material. 
     The normal-state colors of VC court portions  1240 ,  1242 ,  1244 , and  1246  or  1270 ,  1272 ,  1274 , or  1276  are the same in one embodiment of IP structure  1230  or  1260 . In another embodiment, the normal-state colors of portions  1240 ,  1242 , and  1244  or  1270 ,  1272 , and  1274  are the same and differ materially from the normal-state color of OB portions  1246  or  1276 . In a third embodiment, the normal-state colors of SC portions  1240 NL and  1240 FR or  1270 NL and  1270 FR are a first color, the normal-state colors of SC portions  1240 NR and  1240 FL or  1270 NR and  1270 FL are a second color, the normal-state colors of BC portions  1242  or  1272  are a third color, and the normal-state colors of HA portions  1244  or  1274  are a fourth color where the four numbered colors differ materially from one another and from the normal-state color of OB portions  1246  or  1276 . 
     The changed-state color of SC portion  1240 NL,  1240 NR,  1240 FL, or  1240 FR can selectively differ materially among SC parts  1240 ANL,  1240 SNL, and  1240 CNL,  1240 ANR,  1240 SNR, and  1240 CNR,  1240 AFL,  1240 SFL, and  1240 CFL, or  1240 AFR,  1240 SFR, and  1240 CFR. The changed-state color of BC portion  1242 N or  1242 F can selectively differ materially among BC parts  1242 EN,  1242 SN,  1242 BNL, and  1242 BNR or  1242 EF,  1242 SF,  1242 BFL, and  1242 BFR. The changed-state color of HA portion  1244 NL,  1244 NR,  1244 FL, or  1244 FR can selectively differ materially among HA parts  1244 DNL,  1244 ENL,  1244 BNL, and  1244 ANL,  1244 DNR,  1244 ENR,  1244 BNR, and  1244 ANR,  1244 DFL,  1244 EFL,  1244 BFL, and  1244 AFL, or  1244 DFR,  1244 EFR,  1244 BFR, and  1244 AFR. The changed-state color of OB portion  1246 N or  1246 F can selectively differ materially among OB parts  1246 DNL,  1246 ENL,  1246 ENC,  1246 ENR, and  1246 DNR or  1246 DFL,  1246 EFL,  1246 EFC,  1246 EFR, and  1246 DFR. Similarly, the changed-state color of OB portion  1276 N or  1276 F can selectively differ materially among OB parts  1276 DNL,  1276 ENL,  1276 ENC,  1276 ENR, and  1276 DNR or  1276 DFL,  1276 EFL,  1276 EFC,  1276 EFR, and  1276 DFR. Changed-state line color YL can selectively differ materially from the changed-state colors of VC court portions  1240 ,  1242 ,  1244 , and  1246  or  1270 ,  1272 ,  1274 , and  1276 . 
     Taking note of the above-described areas critical to making in/out determination on balls impacting at/near lines  28 ,  30 ,  34 ,  36 , and  46 , changed-state line color YL in a first embodiment of IP structure  1230  or  1260  differs materially from the changed-state LA colors of CLA SC parts  1240 C, SVLA BC parts  1242 S, and singles SLA HA parts  1244 ANL,  1244 ANR,  1244 AFL, and  1244 AFR (collectively “ 1244 A”) or CLA SC portions  1270 , SVLA BC portions  1272 , and singles SLA HA parts  1274 ANL,  1274 ANR,  1274 AFL, and  1274 AFR (collectively “ 1274 A”) for assisting an observer in visually making in/out determinations on object  104  embodied with a served ball impacting at/near the outside edge of at least one of centerline  36 , servicelines  34 , and parts  1232 ANL,  1232 ANR,  1232 AFL, and  1232 AFR (collectively “ 1232 A”) or  1262 ANL,  1262 ANR,  1262 AFL, and  1262 AFR (collectively “ 1262 A”) of singles sidelines  30 . In a second embodiment, line color YL differs materially from the changed-state LA colors of singles SLA HA parts  1244 Q and OB BLA parts  1246 ENC and  1246 EFC or single SLA HA portions  1274  and OB BLA parts  1276 ENC and  1276 EFC for assisting an observer in visually making in/out determinations on object  104  embodied with a returned ball impacting at/near the outside edge of one or more of singles sidelines  30  and parts  1232 ENC and  1232 EFC or  1262 ENC and  1262 EFC of baselines  28  during singles. In a third embodiment, color YL differs from the changed-state LA colors of OB LA portions  1246  or  1276  for assisting an observer in visually making in/out determinations on object  104  embodied with a returned ball impacting at/near the outside edge of one or more of baselines  28  and doubles sidelines  46  during doubles. A fourth embodiment has all the color differences of the second and third embodiments. A fifth embodiment has all the color differences of the first, second, and third embodiments. 
     IP structures  1230  and  1260  are now further described in three-dimensional structural terminology adapted to tennis where color regions  906  and  908  and color SF zones  912  and  914  are respectively replaced with color regions  106  and  108  and color SF zones  112  and  114  as described above. For this structural description, each VC line structure consists of one or more units of AD VC region  886  extending to surface  102  at a VC line area constituted with part or all of VC line area  1232 T or  1262 T. Each other VC structure, i.e., each VC LA structure, consists of one or more units of PP VC region  106  at a corresponding VC LA area. Each FC line structure consists of one or more units of subordinate FC region  888  extending to surface  102  at an FC line area. Each other FC structure consists of one or more units of secondary FC region  108  extending to surface  102  at a corresponding FC area. 
     Each IP structure  1230  or  1260  consists, for singles, of total singles IB structure and total singles OB structure extending to surface  102  respectively at singles IB playing area  22  and singles OB playing area  24 . The total singles OB structure laterally surrounds the total singles IB structure and adjoins it along its entire lateral boundary so that OB area  24  surrounds IB area  22  and adjoins it along its entire perimeter. The total singles IB structure is formed with IB SC structure, singles IB BC structure, and singles IB line structure. 
     The IB SC structure which extends to surface  102  at IB SC area formed with servicecourts  38  consists of VC LA SC structure and FC SC structure. The VC LA SC structure consists of four VC LA SC structure portions extending to surface  102  respectively at LA SC area portions  1240  or  1270  that form VC LA SC area. The FC SC structure consists of four FC SC structure parts extending to surface  102  respectively at SC area parts  1250  or  1280 . The singles IB BC structure which extends to surface  102  at singles IB BC area formed with backcourts  40  consists of VC singles LA BC structure and FC singles BC structure. The VC singles LA BC structure consists of two spaced-apart VC singles LA BC structure portions extending to surface  102  respectively at two spaced-apart VC singles LA BC area portions, one for each half court, that form VC singles LA BC area. Each VC singles LA BC area portion consists of an LA BC area portion  1242  or  1272 . The FC singles BC structure consists of two spaced-apart FC singles BC structure parts extending to surface  102  respectively at BC area parts  1252  or  1282 . 
     The singles IB line structure extends to surface  102  at singles IB line area formed with singles sidelines  30 , servicelines  34 , centerline  36 , and the parts of baselines  28  lying between sidelines  30 . The singles IB line structure consists of VC singles line structure and potentially FC singles line structure as arises in IP structure  1260 . The VC singles line structure extends to surface  102  at composite VC singles line area formed with the portion of line area  1232 T or  1262 T at sidelines  30 , servicelines  34 , centerline  36 , and the parts of baselines  28  lying between sidelines  30 . The composite VC singles line area is specifically formed with near and far VC singles line areas respectively in the near half and far courts. The near VC singles line area consists of line parts  1232 ENC,  1232 SNL,  1232 SNR,  1232 QNL,  1232 QNR, and  1232 CN or  1262 ENC,  1262 SNL,  1262 SNR,  1262 QNL,  1262 QNR, and  1262 CN. The far VC singles line area consists of line parts  1232 EFC,  1232 SFL,  1232 SFR,  1232 QFL,  1232 QFR, and  1232 CF or  1262 EFC,  1262 SFL,  1262 SFR,  1262 QFL,  1262 QFR, and  1262 CF. The FC singles line structure, if present, extends to surface  102  at FC singles line area consisting of one or more parts of the singles IB line area beyond (or outside) the VC singles line area. The FC singles line area for IP structure  1260  consists of line parts  1264 A and  1264 C. 
     The total singles OB structure consists of VC singles OB LA structure and “FC singles OB structure”. The VC singles OB LA structure consists of two VC singles OB LA structure portions extending to surface  102  respectively at two VC singles OB LA area portions that form VC singles OB LA area. Each VC singles OB LA area portion consists at least of the part of an OB LA portion  1246  or  1276  lying along a shortened baseline  28 , i.e., the part of a baseline  28  between singles sidelines  30 , and preferably includes the area of LA HA portions  1244  or  1274  along lines  30  so as to form a ␣-shaped area portion discontinuous at the corners. In particular, the VC singles OB LA area portion along the near or far half court in IP structure  1230  preferably consists of central OB BLA part  1246 ENC or  1246 EFC and singles SLA HA parts  1244 QNL and  1244 QNR or  1244 QFL and  1244 QFR. The VC singles OB LA area portion along the near or far half court in IP structure  1260  preferably consists of central OB BLA part  1276 ENC or  1276 EFC and singles SLA HA portions  1274 NL and  1274 NR or  1274 FL and  1274 FR. 
     The FC singles OB structure extends to surface  102  at “FC singles OB area” formed with the part of singles OB area  24  beyond the VC singles OB area. During singles, any color change occurring in any part of the FC singles OB area due to that part being a VC part for doubles is ignored. Each such VC doubles part of the FC singles OB area is treated as being fixed color during singles. Alternatively, the CC capability of each such VC doubles part of the FC singles OB area is deactivated (or disabled) for singles as described below. The FC singles OB area for IP structure  1230  consists of HA parts  1254 , doubles OB part  1256 , and the intervening FC-treated or CC-deactivated parts of VC HA portions  1244 , line area  1232 T, and OB portions  1246 . The FC singles OB area for IP structure  1260  consists of HA parts  1284 , doubles OB part  1286 , and the intervening FC-treated or CC-deactivated parts of VC line area  1262 T and OB portions  1276 . The VC singles OB area partly occupies singles OB area  24  so that the VC and FC singles OB areas form OB area  24 . 
     Each IP structure  1230  or  1260  consists, for doubles, of total doubles IB structure and total doubles OB structure respectively extending to surface  102  at doubles IB area  42  and doubles OB area  44 . The total doubles OB structure laterally surrounds the total doubles IB structure and adjoins it along its entire lateral boundary so that OB area  44  surrounds IB area  42  and adjoins it along its entire perimeter. The total doubles IB structure is formed with the IB SC structure described above, doubles IB BC structure, IB alley (or HA) structure, and doubles IB line structure. 
     The doubles IB BC structure which, as with the singles IB BC structure, extends to surface  102  at doubles IB BC area formed with backcourts  40  consists of “VC doubles LA BC structure” and “FC doubles BC structure”. The VC doubles LA BC structure consists of two spaced-apart VC doubles LA BC structure portions extending to surface  102  respectively at two spaced-apart “VC doubles LA BC area portions”, one for each half court, that form VC doubles LA BC area. Each VC doubles LA BC area portion consists of the parts of an LA BC portion  1242  along serviceline  34  and baseline  28  in a backcourt  40  so as to partly occupy that backcourt  40  or an LA BC portion  1272  situated in, and partly occupying, a backcourt  40 . Specifically, each VC doubles LA BC area portion for IP structure  1230  consists of LA BC parts  1242 SN and  1242 EN or  1242 SF and  1242 EF. Each VC doubles LA BC area portion for IP structure  1260  consists of LA BC portion  1272 N or  1272 F. 
     Singles SLA BC parts  1242 B in IP structure  1230  may be included in the VC doubles LA BC area if the CC capability of those SLA BC area parts is activated (or enabled) during doubles. Any color change occurring only at any of those VC singles SLA BC area parts is ignored in doubles. Alternatively, the CC capability in those VC singles SLA BC area parts is deactivated for doubles as described below so that they are excluded from the VC doubles LA BC area. The FC doubles BC structure consists of two spaced-apart FC doubles BC structure parts extending to surface  102  respectively at two spaced-apart “FC doubles BC area parts”. Each FC doubles BC area part consists of a BC part  1252 N or  1252 F including, if their CC capability is deactivated during doubles, VC singles SLA BC parts  1242 BNL and  1242 BNR or  1242 BFL and  1242 BFR in a backcourt  40 N or  40 F or a BC part  1282  in a backcourt  40 . 
     The IB alley structure which extends to surface  102  at IB alley area formed with alleys  48  consists of VC LA alley (or HA) structure and FC alley (or HA) structure. The VC LA alley structure consists of four VC singles LA HA structure portions extending to surface  102  respectively at LA HA area portions  1244  or  1274  that form VC singles LA alley (or HA) area. The FC alley structure consists of four FC HA structure parts extending to surface  102  respectively at HA area parts  1254  or  1284 . 
     The doubles IB line structure extends to surface  102  at doubles IB line area formed with baselines  28 , servicelines  34 , centerline  36 , doubles sidelines  46 , and the parts of singles sidelines  30  along servicecourts  38 . The doubles IB line structure consists of VC doubles line structure and potentially FC doubles line structure as arises in IP structure  1260 . The VC doubles line structure extends to surface  102  at VC doubles line area formed with the part of VC line area  1232 T or  1262 T at baselines  28 , servicelines  34 , centerline  36 , doubles sidelines  46 , and the parts of singles sidelines  30  adjoining servicecourts  38 . 
     Singles sideline parts  1232 BNL,  1232 BNR,  1232 BFL, and  1232 BFR (collectively “ 1232 B”) or  1262 BNL,  1262 BNR,  1262 BFL, and  1262 BFR (collectively “ 1262 B”) adjoining backcourts  40  may be included in the VC doubles line area if the CC capability in those BC-adjoining VC singles sideline area parts is activated during doubles. Any color change occurring only at those VC singles sideline area parts is ignored in doubles. Alternatively, the CC capability in those VC singles sideline area parts is deactivated for doubles as described below so that they are excluded from the VC doubles line area. The VC doubles line area specifically consists of line parts  1232 SNL,  1232 SNR,  1232 SFL, and  1232 SFR (collectively “ 1232 S”),  1232 ENL,  1232 ENC,  1232 ENR,  1232 EFL,  1232 EFC, and  1232 EFR (collectively “ 1232 E”),  1232 DNL,  1232 DNR,  1232 DFL, and  1232 DFR (collectively (“ 1232 D”),  1232 A, and  1232 C or  1262 SNL,  1262 SNR,  1262 SFL, and  1262 SFR (collectively “ 1262 S”),  1262 ENL,  1262 ENC,  1262 ENR,  1262 EFL,  1262 EFC, and  1262 EFR (collectively “ 1262 E”),  1262 DNL,  1262 DNR,  1262 DFL, and  1262 DFR (collectively “ 1262 D”),  1262 A, and  1262 C and BC-adjoining singles sideline parts  1232 B or  1262 B if their CC capability is activated during doubles. 
     The FC doubles line structure, if present, extends to surface  102  at FC doubles line area consisting of the parts of the doubles IB line area beyond the VC doubles line area. The FC doubles line area for IP structure  1260  consists of line parts  1264 A,  1264 C, and  1264 D. 
     The total doubles OB structure consists of VC doubles OB LA structure and FC doubles OB structure. The VC doubles OB LA structure consists of two VC doubles OB LA structure portions extending to surface  102  respectively at doubles OB LA portions  1246  or  1276  that form VC doubles OB LA area. The FC doubles OB structure extends to surface  102  at FC doubles OB area formed with doubles OB area part  1256  or  1286  beyond the VC doubles OB area. 
     Each IP structure  1230  or  1260  consists, for singles and doubles, of total singles/doubles IB structure and total singles/doubles OB structure respectively extending to surface  102  at doubles areas  42  and  44 . The total singles/doubles IB structure is formed with the IB SC structure, the singles IB BC structure, the IB alley (or HA) structure, and singles/doubles IB line structure extending to surface  102  at singles/doubles IB line area formed with lines  28 ,  30 ,  34 ,  36 , and  46 . The singles/doubles IB line structure consists of VC singles/doubles line structure and potentially FC singles/doubles line structure as arises in IP structure  1260 . The VC singles/doubles line structure extends to surface  102  at composite VC singles/doubles line area formed with line area  1232 T or  1262 T. The FC singles/doubles line structure, if present, extends to surface  102  at FC singles/doubles line area consisting of the parts of the singles/doubles IB line area beyond the VC singles/doubles line area. The FC singles/doubles line area for structure  1260  consists of singles/doubles line area  1264 T. The total singles/doubles OB structure which laterally surrounds the total singles/doubles IB structure and adjoins it along its entire lateral boundary, consists of VC singles/doubles OB LA structure and FC singles/doubles OB structure respectively formed with the VC and FC doubles OB structures. 
     Each VC LA SC, VC singles LA BC, VC LA HA, or VC doubles OB LA structure portion normally appears along its SC area portion ( 1240  or  1270 ), singles BC area portion ( 1242  or  1272 ), HA area portion ( 1244  or  1274 ), or doubles OB area portion ( 1246  or  1276 ) as a PP SC color ASC, PP BC color ABC, PP HA color AHA, or PP OB color AOB embodying PP color A. Each VC doubles LA BC or VC singles OB LA structure portion normally appears along its doubles BC or singles OB area portion (described above) as color ABC or AOB. The VC singles or doubles line structure normally appears along the VC singles or doubles line area (described above) as AD line color BL embodying AD color B. 
     Using the designations in Table 3, SC color ASC is color ASNL for SC portion  1240 NL or  1270 NL, color ASNR for SC portion  1240 NR or  1270 NR, color ASFL for SC portion  1240 FL or  1270 FL, and color ASFR for SC portion  1240 FR or  1270 FR. BC color ABC is color ABN for singles BC portion  1242 N or  1272 N and color ABF for singles BC portion  1242 F or  1272 F. Similarly, color ABC is color ABN for the VC doubles BC area portion in the near half court and color ABF for the VC doubles BC area portion in the far half court. HA color AHA is color AHNL for HA portion  1244 NL or  1274 NL, color AHNR for HA portion  1244 NR or  1274 NR, color AHFL for HA portion  1244 FL or  1274 FL, and color AHFR for HA portion  1244 FR or  1274 FR. OB color AOB is the same for both doubles OB portions  1246  or  1276  and for both singles OB area portions. 
     IDVC portion  138  of a VC LA SC, singles LA BC, LA HA, or doubles OB LA structure portion responds to object  104  impacting the SC area portion ( 1240  or  1270 ), singles BC area portion ( 1242  or  1272 ), HA area portion ( 1244  or  1274 ), or doubles OB area portion ( 1246  or  1276 ) of that structure portion at OC area  116  by temporarily appearing as a changed SC color XSC, changed BC color XBC, changed HA color XHA, or changed OB color XOB embodying changed color X and materially different from color ASC, ABC, AHA, or AOB of that structure portion if the impact meets PP basic TH impact criteria of that structure portion. Portion  138  of a VC doubles LA BC or singles OB LA structure portion responds to object  104  impacting the doubles BC or singles OB area portion (described above) of that structure portion at area  116  by temporarily appearing as color XBC or XOB of that structure portion if the impact meets PP basic TH impact criteria of that structure portion. Each VC LA structure portion preferably includes components  182  and  184  typically implemented as in OI structure  200 . IS segment  192  provides the PP general impact effect in response to object  104  impacting the area portion of that LA structure portion at area  116  if the impact meets the basic TH impact criteria of that structure portion. CC segment  194  responds to the PP impact effect, if provided, by causing portion  138  of that structure portion to temporarily appear as changed color XSC, XBC, XHA, XOB, XBC, or XOB. 
     Again using the designations in Table 3, SC color XSC is color XSNL for SC portion  1240 NL or  1270 NL, color XSNR for SC portion  1240 NR or  1270 NR, color XSFL for SC portion  1240 FL or  1270 FL, and color XSFR for SC portion  1240 FR or  1270 FR. BC color XBC is color XBN for singles BC portion  1242 N or  1272 N and color XBF for singles BC portion  1242 F or  1272 F. Similarly, color XBC is color XBN for the VC doubles BC area portion in the near half court and color XBF for the VC doubles BC area portion in the far half court. HA color XHA is color XHNL for HA portion  1244 NL or  1274 NL, color XHNR for HA portion  1244 NR or  1274 NR, color XHFL for HA portion  1244 FL or  1274 FL, and color XHFR for HA portion  1244 FR or  1274 FR. OB color XOB is color XOBN for doubles OB portion  1246 N or  1276 N and color XOBF for doubles OB portion  1246 F or  1276 F. Color XOB is also color XOBN for the singles OB area portion along the near half court and color XOBF for the singles OB area portion along the far half court. 
     IDVC portion  926  of the VC singles or doubles line structure responds to object  104  impacting the VC singles or doubles line area (described above) at OC area  896  by temporarily appearing as altered line color YL embodying altered color Y and materially different from AD color BL of the VC singles or doubles line structure if the impact meets AD basic TH impact criteria of the VC singles or doubles line structure. The VC singles or doubles line structure preferably includes IS component  932  and CC component  934  typically implemented as in OI structure  930 . The ID segment of component  932  provides the AD general impact effect in response to the impact if it meets the basic TH impact criteria of the VC singles or doubles line structure. The ID segment of component  934  responds to the AD impact effect, if provided, by causing portion  926  to temporarily appear as altered color YL. 
     Object  104  is typically a (tennis) ball. The PP and AD basic TH impact criteria are then chosen to be suitable for expected impacts of balls on surface  102  during tennis play. For singles, color change occurs at each location of the VC LA SC, singles LA BC, singles OB LA, and singles line areas for ball impacts on surface  102  sufficient to meet the appropriate basic TH impact criteria. For doubles, color change similarly occurs at each location of the VC LA SC, doubles LA BC, LA alley, doubles OB LA, and doubles line areas for ball impacts on surface  102  sufficient to meet the appropriate basic TH impact criteria. 
     The critical edge of each line  28 ,  30 ,  34 , or  46  is, as indicated above, its outside edge since a ball embodying object  104  is “out” only if the ball impacts surface  102  fully beyond (or outside) line  28 ,  30 ,  34 , or  46  insofar as it defines an in/out location. The highest location priority for providing lines  28 ,  30 ,  34 , and  46  with CC capability is elongated area, usually straight, lying directly along the outside edge of each line  28 ,  30 ,  34 , or  46  as occurs with VC court parts/portions  1242 S,  1244 Q, and  1246  or  1272 ,  1274 , and  1276 . 
     The CC capability is, for instance, provided as highest CC location priority in elongated area directly along the critical outside edge of the composite boundary line consisting (a) for singles of shortened baselines  28  and singles sidelines  30  and (b) for doubles of baselines  28  and doubles sidelines  46 . Since each edge of centerline  36  for a served ball variously constitutes the outside, and thus critical, edge depending on servicecourt  38  to which the ball is to be directed, the highest location priority for providing line  36  with CC capability is elongated area, usually straight, lying directly along each edge of line  36  as occurs with VC SC parts/portions  1240 C or  1270 . The next highest location priority for providing line  28 ,  30 ,  34 ,  36 , or  46  with CC capability is all or part of line  28 ,  30 ,  34 ,  36 , or  46  as occurs with VC line area  1232 T or  1262 T. 
     Alleys  48  are deleted in variations of IP structures  1230  and  1260  intended only for singles by deleting doubles sidelines  46  and the parts of baselines  28  along alleys  48  so that doubles sideline parts  1232 D or  1262 D and baseline parts  1232 ENL,  1232 ENR,  1232 EFL, and  1232 EFR or  1262 ENL,  1262 ENR,  1262 EFL, and  1262 EFR cease to exist. With baselines  28  shortened to extend only between singles sidelines  30 , OB LA parts  1246 D,  1246 ENL,  1246 ENR,  1246 EFL, and  1246 EFR or  1276 D,  1276 ENL,  1276 ENR,  1276 EFL, and  1276 EFR are also deleted along with doubles SLA HA parts  1244 D and BLA HA parts  1244 E. Remaining singles SLA HA parts/portions  1244 Q or  1274  are extended to remaining OB BLA parts  1246 ENC and  1246 EFC or  1276 ENC and  1276 EFC along shortened baselines  28  and become parts of OB portions  1246  or  1276 . 
     With HA court portions  1244  or  1274  so adjusted, the VC singles OB structure in the singles-only variation of IP structure  1230  or  1260  consists of two VC singles OB structure portions extending to surface  102  respectively at two ␣-shaped near VC singles OB area portions for the near and far half courts. The near VC singles OB area portion consists of so-adjusted OB LA parts  1244 QNL,  1246 ENC, and  1244 QNR or  1274 NL,  1276 ENC, and  1274 NR. The far VC singles OB area portion similarly consists of so-adjusted OB LA parts  1244 QFL,  1246 EFC, and  1244 QFR or  1274 FL,  1276 EFC, and  1274 FR. The VC singles OB area portions are usually symmetrical about the court&#39;s longitudinal axis and mirror images about the court&#39;s transverse axis. The portion of singles OB area  24  beyond the VC singles OB area portions is a rectangular annular remainder FC singles OB area portion which fully directly surrounds the VC singles OB area formed with the VC singles OB area portions. 
     The singles-only tennis IP structure operates basically the same as singles/doubles IP structure  1230  or  1260  used for singles except that alleys  48  are absent. In particular, the above description of the operation of structure  1230  or  1260  applies to the singles-only IP structure subject to ignoring the material dealing with the VC doubles LA BC, LA alley, doubles OB LA, and doubles line structures and replacing recitations of the VC singles OB LA structure with recitations of the VC singles OB LA structure as modified here. 
     Each of IP structures  1230  and  1260 , including the singles-only variations, preferably contains CC controller  1114  or  1134  either for implementing IP structure  1110  or  1130  that includes OI structure  900  or  1100  or for implementing IP structure  1170  or  1200  that includes both OI structure  900  or  1100  and IG system  1152  or  1182 . Controller  1114 / 1134  here preferably operates as an intelligent controller as described above. In that case, controller  1114 / 1134  usually causes color change only when the impact characteristics meet the PP, AD, FR, or CP expanded impact criteria for a ball impact where the FR expanded impact criteria are again replaced with PP expanded impact criteria for the reasons presented above. Color change generally does not occur when an object, such as a shoe, whose print area differs from that of a ball impacts the court. If a ball lies on the court at a location having the CC capability, a temporary color change either does not occur if the ball&#39;s impact with the court is insufficient to meet the PP, AD, or CP general or cellular TH impact criteria or does not persist beyond automatic length Δt drau , usually no more than 60 s, often no more than 30 s, of CC duration Δt dr  unless instruction  608  is supplied to controller  1114 / 1134  to increase duration Δt dr . 
     The following occurs when controller  1114  is an intelligent controller. IDVC portion  138  of each VC LA SC, singles LA BC, LA HA, or doubles OB LA structure portion responds to object  104  impacting the SC area portion ( 1240  or  1270 ), singles BC area portion ( 1242  or  1272 ), HA area portion ( 1244  or  1274 ), or doubles OB area portion ( 1246  or  1276 ) of that structure portion at OC area  116  by providing a PP general CI impact signal if the impact meets the PP basic TH impact criteria of that structure portion. The impact signal identifies an expected location of print area  118  in that area portion and PP supplemental impact information for the impact. Controller  1114  responds to the impact signal by determining whether the PP supplemental impact information meets PP supplemental impact criteria of that structure portion and, if so, provides a PP general CC initiation signal to which that portion  138  responds by temporarily appearing as changed color XSC, XBC, XHA, or XOB. Portion  138  of a VC doubles LA BC or singles OB LA structure portion interacts with controller  1114  the same as portion  138  of a VC singles LA BC or doubles OB LA structure portion for potentially causing portion  138  of that structure portion to temporarily appear as color XBC or XOB. Each VC LA structure portion again preferably includes components  182  and  184  typically implemented as in OI structure  200 . IS segment  192  provides a PP general impact signal in response to object  104  impacting the area portion of that LA structure portion at area  116  if the impact meets the basic TH impact criteria of that structure portion. CC segment  194  responds to the initiation signal, if provided, by causing portion  138  of that structure portion to temporarily appear as color XSC, XBC, XHA, XOB, XBC, or XOB. 
     An IDVC portion  926  of the VC singles or doubles line structure responds to object  104  impacting the VC singles or doubles line area at OC area  896  by providing an AD general CI impact signal if the impact meets the AD basic TH impact criteria of the VC singles or doubles line structure. The impact signal identifies an expected location of print area  898  in the VC singles or doubles line area and AD supplemental impact information for the impact. Controller  1114  responds to the AD general CI impact signal by determining whether the AD supplemental impact information meets AD supplemental impact criteria of the VC singles or doubles line structure and, if so, provides an AD general CC initiation signal to which that portion  926  responds by temporarily appearing as altered line color YL. The VC singles or doubles line structure again preferably includes IS component  932  and CC component  934  typically implemented as in OI structure  930 . The ID segment of component  932  provides an AD general impact signal in response to the impact if it meets the basic TH impact criteria of the VC singles or doubles line structure. The ID segment of component  934  responds to the initiation signal, if provided, by causing that portion  926  to temporarily appear as color YL. 
     For an impact solely on SF zone  112  or  892  sufficient to meet the PP or AD basic TH impact criteria, controller  1114  determines whether the PP or AD general supplemental impact information meets the PP or AD supplemental impact criteria implemented to be characteristic of a ball impacting surface  102 . For an impact simultaneously on zones  112  and  892  sufficient to meet the CP basic TH impact criteria, controller  1114  determines whether the CP general supplemental impact information meets the CP supplemental impact criteria implemented the same to be characteristic of a ball impacting surface  102 . 
     Print area  118  or  898  is usually roughly elliptical for a ball impact. The short diameter of the rough ellipse for a ball impact is typically in the vicinity of half the diameter of a ball dependent on various factors including the impact angle, vertical impact speed, and court characteristics. The ratio of the long ellipse diameter to the short ellipse diameter for a ball impact depends on various factors including the impact angle, lateral impact speed, and court characteristics. The ellipse diameter ratio typically varies from 1 (circular) to 3 or 4. This information is used to incorporate ball size and/or shape specifications into the PP, AD, and CP supplemental impact criteria. Inasmuch as the shoeprint of a person such as a tennis player is almost invariably considerably different from the size and shape of area  118  or  898  for a ball impact, controller  1114  causes color changes to occur at object-impact locations when balls impact the court but largely not when peoples&#39; shoes impact the court. With OC duration Δt oc  typically being 4-5 ms, invariably less than 10 ms, for a ball impacting a tennis court, the PP, AD, and CP supplemental impact criteria can include OC duration criteria in which maximum reference OC duration value Δt ocrh  is chosen as described above for the PP supplemental impact criteria to be suitably greater than 5 ms but suitably less than the time period during which either shoe of a person contacts the court. 
     The operation is basically the same when controller  1134  is an intelligent controller here. The PP or AD cellular CI impact signals provided from all TH CM cells  404  or  1084  to controller  1134  embody the PP general CI impact signal. The PP or AD cellular CC initiation signals provided by controller  1134  to all full CM cells  404  or  1084  embody the PP general CC initiation signal. 
     Object  104  embodied with a (tennis) ball is termed ball  104  in the following material dealing with IP structures  1230  and  1260 . One part, termed the VC service strip, of the units of VC regions  106  and  886  is used in determining whether ball  104  is “in” or “out” after it is served. Another part, termed the VC return strip, of the units of regions  106  and  886  is used in determining whether ball  104  is “in” or “out” during subsequent return play. The VC service strip differs from the VC return strip which differs between singles and doubles. The service strip and the return strip for singles have four common portions, termed VC sideline common substrips, extending along singles sidelines  30  on both sides of the net line so that each VC sideline common substrip is associated with a different one of servicecourts  38 . 
     The VC service strip consists of (a) the units of VC region  886  extending to surface  102  at VC service-strip line area formed with the VC area at centerline  36 , servicelines  34 , and the parts of singles sidelines  30  extending between servicelines  34  and (b) the units of region  106  extending to surface  102  at VC service-strip LA area formed with the VC area lying fully along the VC service-strip line area. The VC service-strip line area consists of line parts  1232 C,  1232 S, and  1232 A or  1262 C,  1262 S, and  1262 A. The VC service-strip LA area consists of LA parts/portions  1240 ,  1242 S,  1244 A or  1270 ,  1272 , and  1274 A. The service-strip line and LA areas form VC service-strip composite area. 
     The VC return strip for singles consists of (a) the units of VC region  886  extending to surface  102  at singles VC return-strip line area formed with the VC area at singles sidelines  30  and the portions of baselines  28  extending between sidelines  30  and (b) the units of VC region  106  extending to surface  102  at singles VC return-strip LA area formed with the VC area lying fully along the singles VC return-strip line area. The singles VC return-strip line area consists of line parts  1232 QNL,  1232 QNR,  1232 QFL, and  1232 QFR (collectively “ 1232 Q”),  1232 ENC, and  1232 EFC or  1262 QNL,  1262 QNR,  1262 QFL, and  1262 QFR (collectively  1262 Q”),  1262 ENC, and  1262 EFC. The singles VC return-strip LA area consists of LA parts/portions  1240 A,  1242 B,  1242 E,  1244 Q,  1246 ENC, and  1246 EFC or  1274 ,  1276 ENC, and  1276 EFC. The singles return-strip line and LA areas form singles VC return-strip composite area. 
     The VC return strip for doubles consists of (a) the units of VC region  886  extending to surface  102  at doubles VC return-strip line area formed with the VC area at doubles sidelines  46  and baselines  28  and (b) the units of VC region  106  extending to surface  102  at doubles VC return-strip LA area formed with the VC area lying fully along the doubles VC return-strip line area. The doubles VC return-strip line area consists of line parts  1232 D and  1232 E or  1262 D and  1262 E. The doubles VC return-strip LA area consists of LA parts/portions  1242 E,  1244 E,  1244 D, and  1246  or  1276 . The doubles return-strip line and LA areas form doubles VC return-strip composite area. 
     Each VC sideline common substrip consists of (a) the units of VC region  886  extending to surface  102  at a VC sideline common line area formed with the VC area at the part of a sideline  30  lying fully along a different one of servicecourts  38  and (b) the units of VC region  106  extending to surface  102  at a VC sideline common LA area formed with the VC area lying fully along that VC sideline common line area. The VC sideline common line area for servicecourt  38 NL consists of line part  1232 ANL or  1262 ANL. The VC sideline common LA area for servicecourt  38 NL consists of LA part(s)  1240 ANL and  1244 ANL or  1274 ANL. The VC sideline common line area for servicecourt  38 NR consists of line part  1232 ANR or  1262 ANR. The VC sideline common LA area for servicecourt  38 NR consists of LA part(s)  1240 ANR and  1244 ANR or  1274 ANR. The VC sideline common line area for servicecourt  38 FL consists of line part  1232 AFL or  1262 AFL. The VC sideline common LA area for servicecourt  38 FL consists of LA part(s)  1240 AFL and  1244 AFL or  1274 AFL. The VC sideline common line area for servicecourt  38 FR consists of line part  1232 AFR or  1262 AFR. The VC sideline common LA area for servicecourt  38 FR consists of LA part(s)  1240 AFR and  1244 AFR or  1274 AFR. The sideline common line and LA areas for each servicecourt  38  form a VC sideline common composite area for that servicecourt&#39;s sideline common substrip. 
     A device, typically CC controller  1114 / 1134 , controls the VC strips so that (a) the VC service strip is activated during tennis service, at least as ball  104  impacts surface  102  during service, and is inactivated (or inactive) during return play except, in singles, for the VC sideline common substrips and (b) the VC return strip for singles or doubles is activated during return play and is inactivated during service except, in singles, for the sideline common substrips. The service strip is except, in singles, for the sideline common substrips deactivated after return, or attempted return, of service during a point while ball  104  is crossing, or attempting to cross, over net  32  as the return strip for singles or doubles is activated, the sideline common substrips already being activated in singles. The sideline common substrips are thus continuously activated during a point in singles but, during a point in doubles, only activated during service. Both the service and return strips, including the sideline common substrips, are typically inactivated during time periods between points, e.g., to save power and reduce usage deterioration, but can variously be activated during in-between point periods. 
     One or more persons, such as one or more tennis officials, control the VC strips with a control switch for switching the return strip between singles and doubles and for switching each strip between activated and inactivated conditions subject to the sideline common substrips being continuously activated during a point in singles. The control switch can consist of (a) a two-position switch that switches the return strip between singles and doubles and (b) a three-position switch having (i) a first position in which the service strip is activated and the return strip is inactivated except, in singles, for the sideline common substrips, (ii) a second position in which the return strip is activated and the service strip is inactivated except, in singles, for the sideline common substrips, and (iii) a third position in which both strips are inactivated. The two-position switch is used to select the return strip for singles or doubles prior to a tennis match depending on whether it is singles or doubles. The three-position switch is used during play for activating and deactivating the VC strips as described above. Each control switch can be located on controller  1114 / 1134  or remote from it so as to communicate with it via a COM path. The person(s) operating each control switch can operate it manually or by voice in such a way as to avoid significantly disturbing the players. 
     Alternatively, controller  1114 / 1134  includes a shape-recognition capability for use in automatically activating and deactivating the VC strips as described above. Prior to a tennis match, controller  1114 / 1134  is adjusted to select the return strip for singles or doubles depending on whether the match is singles or doubles. IG structure  804 , specifically image-collecting apparatus  808 , generates a moving image of the server at least during tennis service and return play, typically continuously during play including in-between point periods. Controller  1114 / 1134  receives the moving image via a COM path and analyzes it using the shape-recognition capability to determine when the server is serving and when the server is in return play. When the shape-recognition capability indicates that the server is beginning the serve, controller  1114 / 1134  controls the strips so that the service strip is activated and the return strip for singles or doubles is inactivated subject, in singles, to the sideline common substrips being activated. When the shape-recognition capability indicates that the server has just completed the serve, controller  1114 / 1134  controls the strips so that the return strip for singles or doubles is activated and the service strip is inactivated subject, in singles, to the sideline common substrips being activated. 
     Tennis service during a game is performed with the server&#39;s feet positioned behind a specified one of baselines  28  to one side or the other of the center mark on that line  28  depending on the score of the game. Controller  1114 / 1134  may keep track of the game score and where the server should be positioned, relative to lines  28  and their center marks, for service at the beginning of each point. If so, controller  1114 / 1134  can using this scoring information and attendant expected server positioning information to assist the shape-recognition capability in determining when the server is beginning the serve. 
     By controlling the VC strips in the preceding way, impact of ball  104  on the return strip for singles or doubles immediately prior to service, e.g., as the server bounces ball  104  on or close to adjacent baseline  28 , does not cause that return strip to undergo color change. Nor does impact of either of the server&#39;s shoes on the return strip for singles or doubles during service, i.e., immediately before, as, or immediately after the server strikes ball  104 , cause that return strip to undergo color change. During return play, impact of ball  104  on or along centerline  36  or either serviceline  34  except where it meets singles sidelines  30  similarly does not cause color change. The requirements placed on controller  1114 / 1134  to act as an intelligent controller for differentiating between impacts intended to cause color change and impacts not intended to cause color change are considerably reduced. Controller  1114 / 1134  may sometimes even simply be a duration controller depending on how the strip activation/deactivation is achieved. 
     The VC service strip can be allocated into four partially overlapping portions, termed VC QC substrips, one for each servicecourt  38 . Each VC QC substrip lies fully along a servicecourt  38  and thus along a singles sideline  30 , a serviceline  34 , and centerline  36 . When ball  104  is to be directed toward a servicecourt  38  during tennis service, that servicecourt&#39;s QC substrip, termed the designated QC substrip, can be used in determining whether served ball  104  is “in” or “out”. Each VC QC substrip and the VC return strip for singles have a common portion formed with a different one of the VC sideline common substrips. The two QC substrips in each half court have a common portion, referred to as a VC centerline common substrip, extending along centerline  36  for a total of two VC centerline common substrips. 
     Each VC QC substrip consists of (a) the units of VC region  886  extending to surface  102  at a VC QC substrip line area formed with the VC area at the part of centerline  36  lying fully along a different one of servicecourts  38 , the part of a serviceline  34  lying fully along that servicecourt  38 , and the part of a singles sideline  30  lying fully along that servicecourt  38  and (b) the units, as present, of VC region  106  extending to surface  102  at a VC QC substrip LA area formed with the VC area lying fully along the VC QC substrip line area. The VC QC substrip line and LA areas for each servicecourt  38  form a VC QC substrip composite area for that servicecourt&#39;s QC substrip. Each VC centerline common substrip consists of (a) the units of region  886  extending to surface  102  at a VC centerline common line area formed with the VC area at the part of centerline  36  in each half court and (b) the units, as present, of regions  106  extending to surface  102  at a VC centerline common LA area formed with the VC area lying fully along the VC centerline common line area. The VC centerline common line and LA areas for each half court form a VC centerline common composite area for that half court&#39;s centerline common substrip. 
     Instead of controlling the VC service strip as described above, CC controller  1114 / 1134  provides a capability for controlling the VC QC substrips so that (a) the designated QC substrip is activated during service of a point, at least as ball  104  impacts surface  102  during tennis service, and is inactivated during return play of that point except, in singles, for that section&#39;s sideline common substrip and (b) the three QC substrips for the other three servicecourts  38  are inactivated during both service and return play of that point except, in singles, for those three sections&#39; sideline common substrips. The designated QC substrip is except, in singles, for that substrip&#39;s sideline common substrip deactivated after return, or attempted return, of service during a point while ball  104  is crossing, or attempting to cross, over net  32  as the return strip for singles or doubles is activated, the sideline common substrips already being activated in singles. The sideline common substrips thus are continuously activated during a point in singles but, during a point in doubles, only the sideline common substrip for the designated QC substrip is activated and only during service. Also, the centerline common substrip of each pair of QC substrips on each side of net  32  is activated whenever one of those two QC substrips, e.g., the designated QC substrip, is activated. All four QC substrips and both centerline common substrips are typically inactivated during time periods between points but can be activated during in-between point periods. 
     The VC QC substrips are typically controlled by a person, such as a tennis official, using a control switch for suitably switching the return strip and each QC substrip between activated and inactivated conditions subject to the sideline common substrip of the designated QC substrip being continuously activated during a point in singles. The control switch can consist of (a) a two-position switch for switching the return strip between singles and doubles, (b) a four-position switch for selecting designated servicecourt  38  and thus the designated QC substrip, and (c) a three-position switch having (i) a first position in which the designated QC substrip, including its sideline common and centerline common substrips, is activated while the other three QC substrips, including their sideline common substrips and the other centerline common substrip, and the return strip are inactivated, (ii) a second position in which the return strip is activated and all four QC substrips, including both centerline common substrips, are inactivated except, in singles, for the four sideline common substrips, and (iii) a third position in which the return strip and all four QC substrips, including all four sideline common substrips and both centerline common substrips, are inactivated. The two-position switch is again used to select the return strip for singles or doubles prior to a tennis match depending on whether it is singles or doubles. The four-position and three-position switches are used during play for activating and deactivating the return strip and the QC substrips as described above. 
     In one variation of IP structure  1230  or  1260  applicable to both a singles/doubles implementation and a singles-only variation, the present CC capability is provided only along servicecourts  38  for use in determining whether ball  104  is “in” or “out” during service. That is, only VC line parts  1232 C,  1232 S, and  1232 A or  1262 C,  1262 S, and  1262 A and VC LA parts/portions  1240 ,  1242 S, and  1244 A or  1270 ,  1272 , and  1274 A are present. During service, the receiving player virtually never steps on any of the VC line and LA area parts situated at and alongside designated servicecourt  38  to which served ball  104  is directed. The partner of the receiving player during service in doubles similarly rarely, if ever, ever steps on any of the VC line and LA area parts situated at and alongside designated servicecourt  38 . In view of this, there is no need during service to distinguish between impacts of ball  104  on surface  102  and other impacts on it. Controller  1114 / 1134  is not usually present in this variation. 
     Letting an “out” VC LA structure portion mean a VC LA structure portion (or part) for which an impact is “out” if print area  118  is spaced apart from VC line area  1232 T or  1262 T, controller  1114 / 1134  preferably operates as an intelligent controller using the location-dependent version of the CC capability to control the color changing so that IDVC portion  138  of any “out” VC LA structure portion appears as (i) first changed color X 1  if area  118  of the LA area portion (or part) of that structure portion adjoins line area  1232 T or  1262 T and (ii) second changed color X 2  different from color X 1  if area  118  of the area portion of that structure portion is spaced apart from line area  1232 T or  1262 T. Colors X 1  and X 2  here are respective different embodiments of each changed color XSNL, XSNR, XSFL, XSFR, XBN, XBF, XHNL, XHNR, XHFL, XHFR, XOBN, or XOBF. Color X 1  is preferably the same for all “out” LA structure portions. Color X 2  is also preferably the same for all “out” LA structure portions. 
     During service toward designated servicecourt  38 , the appearance of print area  118  of any of the VC LA area portions, including any segment of those portions, adjoining the part of VC line area  1232 T or  1262 T along the outside edge of that servicecourt  38  as color X i  indicates that served ball  104  is “in” because having area  118  of each such LA area portion adjoin line area  1232 T or  1262 T means that ball  104  impacted the part of area  1232 T adjoining that servicecourt  38  whereas the appearance of each such LA portion as color X 2  indicates that ball  104  is “out” because having area  118  of that LA area portion be spaced apart from area  1232 T or  1262 T means that ball  104  failed to impact the part of area  1232 T or  1262 T adjoining that servicecourt  38  except for the rare instances in which ball  104  simultaneously impacts both that LA portion and FC line area  1264 T in IP structure  1260  without impacting area  1262 T. A viewer, e.g., a player or an official, can nearly always determine whether served ball  104  impacts surface  102  “in” or “out” in IP structure  1230  or  1260  by simply examining the color of area  118 . If ball  104  simultaneously impacts such an LA portion and FC line area  1264 T in structure  1260  without impacting VC line area  1262 T, area  118  lacks the shape for a ball impacting surface  102  at a service “out” location so as to indicate that the in/out status of ball  104  is unclear. 
     The appearance of print area  118  of any of the VC LA area parts adjoining IB area  22  or  42  along baselines  28  or/and sidelines  30  or  46 , as color X 1  during return play in singles or doubles in IP structure  1230  indicates that returned ball  104  is “in” because having area  118  of each such LA area part adjoin area  22  or  42  means that ball  104  impacted area  22  or  42  along baselines  28  or/and sidelines  30  or  46  whereas the appearance of each such LA part as color X 2  indicates that ball  104  is “out” because having area of that LA area part be spaced apart from area  22  or  42  means that ball  104  failed to impact area  22  or  42  along baselines  28  or/and sidelines  30  or  46 . In IP structure  1260 , the appearance of area  118  of any of the VC LA area parts adjoining IB area  22  or  42  along baselines  28  or/and sidelines  30  or  46 , as color X 1  during singles or doubles return play similarly indicates that ball  104  is “in” whereas the appearance of each such LA part as color X 2  indicates that ball  104  is “out” except for the rare instances in which ball  104  simultaneously impacts both that LA part and FC line area  1264 T without impacting VC line area  1262 T. A viewer can again nearly always determine whether returned ball  104  impacts surface  102  “in” or “out” in structure  1230  or  1260  by simply examining the color of area  118 . If ball  104  simultaneously impacts such an LA part and FC line area  1264 T in structure  1260  without impacting VC line area  1262 T, area  118  lacks the shape for a ball impacting surface  102  at a returned “out” location so as to indicate unclarity in the in/out status of ball  104 . 
     Using the sound-generation capability, controller  1114 / 1134  optionally generates an audible sound indicating that ball  104  is “out”, e.g., the word “out” in English, when ball  104  impacts a selected portion of surface  102  where ball  104  is “out” without simultaneously impacting a portion of surface  102  where ball  104  is “in”. The portion of surface  102  where ball  104  is “out” embodies one or more of SF zones  112  and  892 . An audible “out” sound is specifically optionally generated in IP structure  1230  or  1260  ( a ) during tennis service if ball  104  impacts any one or more of the parts of VC court portions  1240 ,  1242 , and  1244  or  1270 ,  1272 , and  1274  along, but outside, designated servicecourt  38  to which ball  104  is directed without simultaneously impacting any part of VC line area  1232 T or  1262 T along that servicecourt  38 , (b) during singles return play if ball  104  impacts any one or more of the parts of VC court portions  1244  and  1246  or  1274  and  1276  along singles IB area  22  without simultaneously impacting any part of line area  1232 T or  1262 T along IB area  22 , and (c) during doubles return play if ball  104  impacts either of VC OB portions  1246  or  1276  without simultaneously impacting any part of area  1232 T or  1262 T along doubles IB area  42 . 
     Impact of ball  104  on surface  102  usually results in an audible ball-impact sound that starts during OC duration Δt oc , typically 4-5 ms, extending from object-impact time t ip  to OS time t os . The out-indicating sound made for ball  104  landing “out” preferably starts both soon after the start of the ball-impact sound so as to be clearly associated with the impact and sufficiently later than the start of the ball-impact sound to avoid having it materially affect the clarity of the out-indicating sound. In particular, the out-indicating sound starts at least 0.1 s, preferably at least 0.25 s, after OS time t os  and no more than 1 s, preferably no more than 0.75 s, more preferably no more than 0.5 s, after time t os . 
     IP structure  1230  or  1260  could provide an audible sound indicating that ball  104  is “in”, e.g., the word “in” in English, when ball  104  impacts surface  102  at any CC location not fully outside designated servicecourt  38  during tennis service, not fully outside singles IB area  22  during singles return play, and not fully outside doubles IB area  42  during doubles return play. However, such a sound is usually not provided because (a) it would be distracting to the tennis players and (b) the non-occurrence of a sound indicating that ball  104  hitting in the immediate vicinity of that location is “out” means that ball  104  is “in”. 
     The invention&#39;s CC capability can be implemented in various tennis situations besides those described above. For instance, the CC capability can be provided (a) along the top of tennis net  32  to determine if an otherwise “good” served ball  104  grazed net  32  in passing over it and must be replayed and (b) along baselines  28  to assist in determining whether a foot fault occurs during service for which controller  1114 / 1134  functions as an intelligent controller sensitive to the shape of a shoe embodying object  104 . 
     Exclusive of the material embodying the units of VC regions  106  and  886 , surface  102  in IP structure  1230  or  1260 , including any of its above-described variations, is typically formed with hard-court material or clay. To avoid or reduce using velocity-restitution matching described below, the present CC capability can be provided only in one or more of the following places in clay-court variations of structure  1230  or  1260  (a) at baselines  28  and or/and along their outside edges, i.e., by line parts  1232 E or  1262 E or/and LA parts  1246 E or  1276 E, (b) at shortened baselines  28  and or/and along their outside edges, i.e., by line parts  1232 ENC and  1232 EFC or  1262 EFC and  1262 EFC or/and LA parts  1246 ENC and  1246 EFC or  1276 ENC and  1276 EFC, in a singles-only variation, (c) at singles sidelines  30  or/and along their outside edges, i.e., by line parts  1232 Q or  1262 Q or/and LA parts/portions  1244 Q or  1274 , especially in a singles-only variation, and (d) at doubles sidelines  46  or/and along their outside edges, i.e., by line parts  1232 D or  1262 D or/and LA parts  1246 D or  1276 D. 
     Incorporating the CC capability into a grass tennis court without significantly affecting the ball-bounce and player shoe-traction characteristics of grass-court play is challenging. Surface  102  for a grass tennis court having the CC capability usually consists of grassy areas at the FC SF zones formed with units of SF zones  114  and  894  and relatively hard areas at the VC SF zones formed with units of SF zones  112  and  892 . The hard areas for the VC SF zones are at the bottoms of channels in the grass. The width of each channel is slightly greater than the sum of the widths of the units of SF zones exposed by that channel. Using these channels, each IP structure  1230  or  1260  is implemented in a grass court without significantly affecting the ball-bounce characteristics of grass-court play by providing surface  102  with good velocity-restitution matching between tennis-ball impacts on the grassy FC SF zones and tennis-ball impacts on the hard VC SF zones. The presence of good velocity-restitution matching across surface  102  is expected to result in the shoe-traction characteristics being only slightly affected as players switch between stepping (partly or fully) on grassy FC SF zones and stepping on hard VC SF zones. It is expected that good tennis players will generally readily adapt to switching between stepping on grassy FC SF zones and stepping on hard VC SF zones. 
     The CC capability is alternatively incorporated into a grass tennis court with VC SF zones provided at the bottoms of channels in the grass in any or more of the following ways to reduce the need for good velocity-restitution matching across surface  102 . Firstly, an elongated straight VC SF zone formed with a BLA part  1246 E or  1276 E is provided fully along the outside edge of each baseline  28  if the court is a singles/doubles court. For a singles-only court having shortened baselines  28 , an elongated straight VC SF zone formed with one of OB BLA parts  1246 ENC and  1246 EFC or  1276 ENC and  1276 EFC is instead provided fully along the outside edge of each shortened baseline  28 . Secondly, for a singles-only court, an elongated straight VC SF zone formed with a singles SLA HA part  1244 Q or  1274  is provided directly along the outside edge of the half of each singles sideline  30  in each half court so as to adjoin that half singles sideline starting from baseline  28  in that half court. If the court has VC BLA SF zones, they merge with the VC singles SLA SF zones to form two ␣-shaped VC OB SF zones. Thirdly, for a singles/doubles court, an elongated straight VC SF zone formed with a double OB SLA part  1246 D or  1276 D is provided directly along the outside edge of the half of each doubles sideline  46  in each half court so as to adjoin that half doubles sideline starting from baseline  28  in that half court. If the court has VC BLA SF zones, they merge with the VC doubles SLA SF zones to form ␣-shaped OB area portions  1246  or  1276 . 
     Any difference between the bounce characteristics of balls impacting the grassy FC SF zones and the bounce characteristics of balls impacting the hard VC LA SF zones during singles point play is largely immaterial for balls solely impacting the hard VC OB BLA SF zones or/and the VC singles (HA or OB) SLA SF zones, or impacting them along any of their outside edges because those balls are “out” to immediately end the points. The same applies to any balls impacting the VC doubles OB SLA SF zones during singles. A difference between the bounce characteristics of balls impacting the grassy FC SF zones and the bounce characteristics of balls impacting the hard VC LA SF zones is of concern for balls impacting (a) the part of a singles sideline  30  along a servicecourt  38  and the adjoining part of the adjoining VC singles SLA SF zone simultaneously during service, (b) a grassy baseline  28  and the adjoining VC OB BLA SF zone simultaneously during return play, (c) a grassy singles sideline  30  and the adjoining VC singles SLA SF zone simultaneously during singles return play, (d) a grassy doubles sideline  46  and the adjoining VC doubles OB SLA SF zone simultaneously during doubles return play, and (e) a grassy singles sideline  30  during doubles return play because those balls are “in”. However, it is expected that good tennis players will generally readily adapt to such a difference in ball-bounce characteristics, especially since the ball-bounce characteristics of grass tennis courts are known to usually be somewhat unpredictable compared to the ball-bounce characteristics of conventional hard-surface and clay tennis courts. 
     The effect of such a difference in ball-bounce characteristics can be significantly reduced by variously replacing the preceding VC LA SF zones with VC SF zones provided at the bottoms of channels in the grass at locations spaced apart from baselines  28 , singles sidelines  30 , and doubles sidelines  46  in each of the following ways for which recitation of such a VC SF zone as being “adjacent” to a line  28 ,  30 , or  46  means that the zone is close to, but spaced apart from, that line  28 ,  30 , or  46 . Firstly, an elongated straight VC SF zone is provided beyond the outside edge of each baseline  28  for a singles/doubles court, or shortened baseline  28  for a singles-only court, to extend the full length of that baseline, or shortened baseline  28 , while being spaced apart from it. The average distance from each such VC OB baseline-adjacent SF zone to closest baseline, or shortened baseline,  28  is usually no greater than the average length, termed the nominal baseline just-out PA distance, of the longitudinally shortest ones of print areas  118  that would arise from balls impacting a VC OB BLA SF zone situated along the outside edge of each line, or shortened line,  28  after being struck from locations close to opposite line, or shortened line,  28  and then moving along trajectories approximately perpendicular to net  32 , “PA” again meaning print-area. By employing VC OB baseline-adjacent SF zones situated approximately the nominal baseline just-out PA distance beyond baselines, or shortened baselines,  28 , color changes occur in those VC SF zones only for balls impacting surface  102  fully beyond lines, or shortened lines,  28  and thus only for balls that are “out”. 
     Secondly, an elongated straight VC SF zone is provided slightly beyond the outside edge of each half singles sideline in a singles-only court to extend generally along, but spaced apart from, that half singles sideline starting from an imaginary straight line extending largely through the inside edge of shortened baseline  28  in that half court so as to terminate past the imaginary extended serviceline in that half court either at the net line or short of the net line usually one fourth to three fourths of the distance from the imaginary extended serviceline in that half court to the net line. The average distance from each such VC singles sideline-adjacent SF zone to closest singles sideline  30  is usually no greater than the average longitudinal width, termed the nominal sideline just-out PA distance, of print areas  118  that would arise from balls impacting a VC SLA SF zone situated along the outside edge of the half of each sideline  30  in each half court after being struck from locations close to shortened baseline  28  in the opposite half court. Use of VC singles sideline-adjacent SF zones situated approximately the nominal sideline just-out PA distance beyond sidelines  30  enables color changes in those VC SF zones to occur only for balls impacting fully beyond sidelines  30  and thus only for balls that are “out” in singles return play. 
     Thirdly, an elongated straight VC OB SF zone is provided slightly beyond the outside edge of each half doubles sideline in a singles/doubles court to extend generally along, but spaced apart from, that half doubles sideline starting from the imaginary straight line extending largely through the inside edge of baseline  28  in that half court so as to terminate past the imaginary extended serviceline in that half court either at the net line or short of the net line usually one fourth to three fourths of the distance from the imaginary extended serviceline in that half court to the net line. The average distance from each such VC doubles OB sideline-adjacent SF zone to closest doubles sideline  46  is usually no greater than the nominal sideline just-out PA distance. By utilizing VC doubles OB sideline-adjacent SF zones situated approximately the nominal sideline just-out PA distance beyond lines  46 , color changes in those VC SF zones occur only for balls impacting fully beyond lines  46  and therefore only for balls that are “out” in doubles return play. 
     Any difference between the bounce characteristics of balls impacting the grassy FC SF zones and the bounce characteristics of balls impacting the hard VC baseline-adjacent and singles sideline-adjacent SF zones during singles point play or impacting the hard VC baseline-adjacent and doubles sideline-adjacent SF zones during doubles point play is largely immaterial for balls solely impacting those VC SF zones, or impacting them along any of their outside edges, because those balls are “out” to immediately end the points. The same usually applies to the large majority of balls impacting the VC baseline-adjacent and singles sideline-adjacent SF zones along their inside edges during singles or impacting the VC baseline-adjacent and doubles sideline-adjacent SF zones along their inside edges during doubles, especially when the average distance between each VC baseline-adjacent SF zone and closest baseline  28  is approximately the nominal baseline just-out PA distance and when the average distance between each VC singles sideline-adjacent SF zone and closest singles sideline  30  or between each VC doubles sideline-adjacent SF zone and closest doubles sideline  46  is approximately the nominal sideline just-out PA distance. A difference between the bounce characteristics of balls impacting the grassy FC SF zones in alleys  48  and the bounce characteristics of balls impacting the hard VC singles sideline-adjacent SF zones in alleys  48  may arise for balls impacting alleys  48  during doubles. Again, it is expected that good tennis players will generally readily adapt to such a difference in ball-bounce characteristics. 
     Advantageously, balls simultaneously impacting each grassy baseline  28  and the FC grassy area between that line  28  and the VC OB baseline-adjacent SF zone closest to that line  28  usually do not incur any significant difference in ball-bounce characteristics even though good velocity-restitution matching may not exist across surface  102 . The same applies to balls simultaneously impacting each grassy singles sideline  30  and the FC grassy area between that sideline  30  and either VC singles sideline-adjacent SF zone closest to that line  30  in singles and to balls simultaneously impacting each grassy doubles sideline  46  and the FC grassy area between that line  46  and either VC doubles sideline-adjacent SF zone closest to that line  46  in doubles. No print area  118  is usually generated for any of these impacts. Since a ball (partly or fully) impacting a baseline  28 , a singles sideline  30  during singles, or a doubles sideline  46  during doubles is “in” during return play, the absence of area  118  generally means that the ball is deemed to be “in”. 
     Balls will occasionally fully impact the grassy area between each VC OB baseline-adjacent SF zone and closest baseline  28  so that the balls are “out” with no print area  118  being generated because the balls do not impact that VC OB baseline-adjacent SF zone. Balls will also occasionally fully impact the grassy area between each VC sideline-adjacent SF zone and closest sideline  30  or  46  so that the balls are “out” with no area  118  being generated because the balls do not impact that VC sideline-adjacent SF zone. Such balls may erroneously be deemed to be “in”. While this is disadvantageous, the disadvantage is well more than overcome by the advantages described in the previous paragraph. 
     The VC OB BLA or baseline-adjacent SF zones are permanent parts of the grass tennis court. The VC singles SLA or singles sideline-adjacent SF zones are permanent parts of the court especially if it lacks alleys  48  and is thereby used only for singles. If the court has alleys  48  and is used for both singles and doubles, the VC singles SLA or singles sideline-adjacent SF zones can be SF zones of removable VC singles SLA or singles sideline-adjacent regions which are installed in the court for singles and can be readily (or easily) removed for doubles and rapidly replaced with corresponding FC regions. The removable VC singles SLA or singles sideline-adjacent regions are reinstalled in the court for later singles play. As one alternative to using removable VC singles SLA or singles sideline-adjacent regions, the IP structure containing the court can include a capability for activating the VC singles SLA or singles sideline-adjacent regions for singles and deactivating them for doubles even though they are still physically present in doubles IB area  42  during doubles. As another alternative to using removable VC singles SLA or singles sideline-adjacent regions, the IP structure can include a capability for deactivating, during doubles, the parts of the VC singles SLA or singles sideline-adjacent regions whose SF zones extend from the imaginary extended servicelines to baselines  28  even though the inactivated parts are still physically present in doubles IB area  42 . In this case, the activated parts of the VC singles SLA or singles sideline-adjacent regions can be used in determining whether served balls impacting surface  102  close to the parts of singles sidelines  30  lying between servicelines  34  are “in” or “out” in doubles play. 
     The VC doubles SLA or doubles sideline-adjacent SF zones can be permanent parts of the grass tennis court and thus be present during both singles and doubles. Alternatively, the VC doubles SLA or doubles sideline-adjacent SF zones can be SF zones of removable or deactivatable VC doubles SLA or doubles sideline-adjacent regions handled in a complementary way to the removable or deactivatable VC singles SLA or singles sideline-adjacent SF regions. However, the presence of the VC doubles SLA or doubles sideline-adjacent regions in OB area  24  during singles will usually have little effect on singles play because the players will only occasionally step on the doubles-SLA or doubles-sideline-adjacent SF zones. 
     Each of the preceding ways and indicated alternatives is, of course, only a partial solution for using the present CC capability to assist in making rapid accurate in/out calls in play on grass tennis courts. Aside from served balls that impact close to singles sidelines  30 , these ways and indicated alternatives for employing the CC capability in grass courts do not provide assistance in determining whether served balls are “in” or “out”. However, in/out decisions on returned balls impacting surface  102  close to baselines  28 , singles sidelines  30  during singles, and doubles sidelines  46  during doubles are often the most difficult determinations to make. The preceding ways and indicated alternatives for utilizing the CC capability in grass courts provide a substantial advancement in making rapid accurate in/out calls. 
     The preceding description of ways to incorporate the CC capability into a grass tennis court assumes that the ball-bounce and player shoe-traction characteristics should be constant across surface  102 . However, the conditions and rules for sports change for various reasons including technology advances. Improved accuracy in making in/out determinations on grass courts may be deemed more important than having the ball-bounce and player shoe-traction characteristics be constant across surface  102 , especially since conventional grass courts have somewhat unpredictable ball-bounce characteristics compared to those of hard-surface and clay tennis courts. It may be acceptable to implement the CC capability into a grass court without significant regard to the ball-bounce and player shoe-traction characteristics. 
     A tennis IP structure according to the invention may have less CC capability than what occurs in either of IP structures  1230  and  1260  and their above-described variations. That is, one or more, but not all, of the VC LA SC, singles or doubles LA BC, doubles or singles OB LA, LA HA, and doubles or singles line structures may be absent depending on whether the IP structure is for singles only or singles and doubles. In general, a singles-only tennis IP structure according to the invention selectively contains one or more of the VC LA SC, singles LA BC, singles OB LA, and singles line structures where the VC singles line structure may consist of less VC singles line structure than the VC singles line structure described above for structure  1230  or  1260 . Similarly, a singles/doubles tennis IP structure according to the invention selectively contains one or more of the VC LA SC, doubles LA BC, alley, doubles OB LA, and singles/doubles line structures where the VC doubles line structure may consist of less VC doubles line structure than what extends to surface  102  at VC line area  1232 T or  1262 T. In one embodiment of a singles-only or singles/doubles IP structure, the CC capability is provided only along the outsides of servicelines  34  and thus is used only in making serviceline in/out determinations on served balls. That is, units of SF zone  112  are embodied only with BC portions  1272  extending along servicelines  34 . This embodiment can be extended to embody units of SF zone  892  with serviceline parts  1262 S. 
     Other Sports Implementations 
     In the following material, a description of three consecutively adjoining VC regions as being respectively embodied (or formed) with (units of) PP VC region  106 , AD VC region  886 , and FR VC region  906  covers the situation in which the three regions are respectively embodied with regions  906 ,  886 , and  106  because reference symbols “ 106 ”, “ 886 ”, and “ 906 ” and the adjective terms “PP”, “AD”, and “FR” for “principal”, “additional”, and “further are arbitrary designators and do not affect the substance of the embodiments. A description of the SF zones of the three VC regions as being respectively embodied with (units of) PP SF zone  112 , AD SF zone  892 , and FR SF zone  912  thus covers the situation in which the three zones are respectively embodied with zones  912 ,  892 , and  112 . A description of two adjoining VC regions as being respectively embodied with (units of) PP region  106  and AD region  886  covers the situation in which the two regions are respectively embodied with regions  906  and  886 . A description of the VC SF zones of the two VC regions as being respectively embodied with (units of) PP zone  112  and AD zone  892  covers the situation in which the two zones are respectively embodied with zones  912  and  892 . 
     The adjectives “AD” and “FR” are interchangeable as applied to VC regions  886  and  906  and elements of those regions such as SF zones  892  and  912 . That is, “AD” region  886  and “AD” zone  892  are alternatively describable as “FR” region  886  and “FR” zone  892 , and vice versa. “LA”, “ALA”, “BLA”, “ELA”, and “SLA” hereafter respectively mean line-adjoining, attack-line-adjoining, baseline-adjoining, endline-adjoining or end-line-adjoining, and sideline-adjoining or side-line-adjoining. “BV” hereafter means boundary-vicinity. 
     Instances occur below in which colors in different sports IP structure are identified with the same names because the lines and LA area portions have the same, or substantially the same, names. In such situations, the name for each such color used in a sports IP structure only applies to that sport structure except as otherwise indicated. All parts of each closed boundary line are usually of the same normal-state color. Each pair of mirror-image regions typically employ normal-state color A, B, or C and changed-state color X, Y, or Z in the same way but can use different embodiments of normal-state color A, B, or C and changed-state color X, Y, or Z. The same applies to regions which are in opposite locations relative to a centerline but are not exactly mirror images as arises in the baseball/softball IP structure of  FIG. 101 , described below, if the outfield area is not symmetrical about the field centerline through the centers of home plate and second base. 
     The FC structures or structure portions that laterally adjoin VC structures or structure portions in the sports IP structures are not expressly described below in order to shorten the description. However, for each recited FC area or area portion in a sports IP structure, the sports structure contains a corresponding FC structure or structure portion consisting of one or more units of FC region  108 ,  888 , or  908  extending to surface  102  at the FC area or area portion. 
     The core of each of the sports-playing IP structures of  FIGS. 98-101  described below is a general sports-playing OI structure implemented with OI structure  900  (sometimes just OI structure  880 ) or, preferably, cell-containing OI structure  1100  (sometimes just OI structure  1080 ). Surface  102  of the general sports-playing OI structure includes at least one finite-width line at or/and directly along which the present CC capability is provided. Each such line, termed an object-related line, has opposite first and second edges. For each object-related line, the general OI structure contains one or more of (a) a VC first-edge LA structure part formed with at least one unit of VC region  106  extending to surface  102  at a VC first-edge LA area part that adjoins the first edge of the line at least partly along its length and normally appearing along the first-edge LA area part as PP color A, (b) a VC line structure part formed with at least one unit of VC region  886  extending to surface  102  at a VC line part extending between the edges of the line at least partly along its length and normally appearing along the line part as AD color B, and (c) a VC second-edge LA structure part formed with a least one unit of VC region  906  extending to surface  102  at a VC second-edge LA area part that adjoins the second edge of the line at least partly along its length and normally appearing along the second-edge LA area part as FR color C. 
     The following operational explanation applies to one object-related line for which its VC line structure part and both of its VC LA structure parts are present in the general OI structure. In the absence of intelligent control provided by controller  1114 / 1134 , IDVC portion  138  of the first-edge structure part responds to object  104  impacting the first-edge area part at OC area  116  by temporarily appearing as changed color X if the impact meets PP basic TH impact criteria of that first-edge structure part. The first-edge structure part preferably includes components  182  and  184  typically implemented as in OI structure  200 . IS segment  192  provides the PP general impact effect in response to the impact if it meets the PP basic TH impact criteria. CC segment  194  responds to the PP impact effect, if provided, by causing portion  138  to temporarily appear as color X. 
     Absent intelligent control, IDVC portion  926  of the line structure part responds to object  104  impacting the line structure part at OC area  896  by temporarily appearing as altered color Y if the impact meets AD basic TH impact criteria of the line structure part. The line structure part preferably includes IS component  932  and CC component  934  typically implemented as in OI structure  930 . The ID segment of IS component  932  provides the AD general impact effect in response to the impact if it meets the AD basic TH impact criteria. The ID segment of CC component  934  responds to the AD impact effect, if provided, by causing portion  926  to temporarily appear as color Y. 
     An FR IDVC portion of the second-edge structure part responds, absent intelligent control, to object  104  impacting the second-edge area part at OC area  916  by temporarily appearing as modified color Z if the impact meets FR basic TH impact criteria of the second-edge structure part. The second-edge structure part preferably includes an IS component and a CC component typically implemented the same as CC component  184  in OI structure  200 . An ID segment of the IS component provides an FR general impact effect in response to the impact if it meets the FR basic TH impact criteria. An ID segment of the CC component responds to the FR impact effect, if provided, by causing the FR IDVC portion to temporarily appear as color Z. 
     Each of these sports-playing IP structures usually contains CC controller  1114  or  1134  either for implementing IP structure  1110  or  1130  that includes OI structure  900  or  1100  or for implementing IP structure  1170  or  1200  that includes OI structure  900  or  1100  and IG system  1152  or  1182 . The following specifically occurs when controller  1114  is implemented as an intelligent controller for assistance in making specified impact determinations for the object-related line. 
     IDVC portion  138  of the first-edge structure part responds to object  104  impacting the first-edge area part at OC area  116  by providing the PP general CI impact signal if the impact meets the PP basic TH impact criteria of the first-edge structure part. The impact signal identifies an expected location of print area  118  in the first-edge area part and PP supplemental impact information for the impact. Controller  1114  responds to the impact signal by determining whether the PP supplemental impact information meets PP supplemental impact criteria of the first-edge structure part and, if so, provides a PP general CC initiation signal to which portion  138  responds by temporarily appearing as changed color X. When the VC first-edge structure part includes components  182  and  184 , IS segment  192  provides an impact signal in response to the impact if it meets the PP basic TH impact criteria. CC segment  194  responds to the initiation signal, if provided, by causing that portion  138  of to temporarily appear as color X. 
     IDVC portion  926  of the VC line structure part responds to object  104  impacting the line area part at OC area  896  by providing the AD general CI impact signal if the impact meets the AD basic TH impact criteria of the line structure part. The impact signal identifies an expected location of print area  898  in the line and AD supplemental impact information for the impact. Controller  1114  responds to the impact signal by determining whether the AD supplemental impact information meets AD supplemental impact criteria of the line structure part and, if so, provides the AD general CC initiation signal to which portion  926  responds by temporarily appearing as altered color Y. When the line structure part includes components  932  and  934 , the ID segment of IS component  932  provides an impact signal in response to the impact if it meets the basic TH impact criteria. The ID segment of CC component  934  responds to the initiation signal, if provided, by causing portion  926  to temporarily appear as color Y. 
     The FR IDVC portion of the second-edge structure part responds to object  104  impacting the second-edge area part at OC area  916  by providing the FR general CI impact signal if the impact meets the FR basic TH impact criteria of the second-edge structure part. The impact signal identifies an expected location of print area  918  in the second-edge area part and FR supplemental impact information for the impact. Controller  1114  responds to the impact signal by determining whether the FR supplemental impact information meets FR supplemental impact criteria of the second-edge structure part and, if so, provides the FR general CC initiation signal to which the FR IDVC portion responds by temporarily appearing as modified color Z. When the second-edge structure part includes IS and CC components, an ID segment of the IS component provides an impact signal in response to the impact if it meets the basic TH impact criteria. An ID segment of the CC component responds to the initiation signal, if provided, by causing the FR IDVC portion to temporarily appear as color Z. 
     The operation is basically the same when each sports-playing IP structure contains controller  1134  implemented as an intelligent controller for assistance in making the specified impact determinations. The PP, AD, or FR cellular CI impact signals provided from all TH CM cells  404 ,  1084 , or  1104  to controller  1134  form the PP, AD, or FR general CI impact signal. The PP, AD, or FR cellular CC initiation signals provided by controller  1134  to all full CM cells  404 ,  1084 , or  1104  form the PP general CC initiation signal. Additionally, simultaneous impact on the line and first-edge area part or/and the second-edge area part is handled as described above for simultaneous impact on SF zones  892  and  112  or/and  912 . 
     Controller  1114 / 1134  may use the location-dependent version of the CC capability to control the color changing so that IDVC portion  138  of the first-edge structure part appears as one of p changed colors XJ 1 , XJ 2 , . . . XJ p  dependent on where print area  118  occurs in SF zone  112  or/and the FR IDVC portion of the second-edge structure part appears as one of r modified colors ZL 1 , ZL 2 , . . . ZL r  dependent on where print area  918  occurs in SF zone  912 . That is, changed color X is specific changed color XJ i  when area  118  satisfies location criterion LJ i  of p location criteria LJ 1 , LJ 2 , . . . LJ p  or/and modified color Z is specific modified color ZL i  when area  918  satisfies location criterion LL i  of r location criteria LL 1 , LL 2 , . . . LL r . The location-dependent CC capability can be performed by having controller  1114  respond to the LI or CI general impact signal in the rudimentary or advanced general embodiment described above or by having controller  1134  respond to the LI or CI cellular impact signals in the rudimentary or advanced cellular embodiment described above. Changed color X is typically (i) changed color XJ 1  if area  118  adjoins the line and (ii) changed color XJ 2  if area  118  is spaced apart from the line. Modified color Z is typically (i) modified color ZL 1  if area  918  adjoins the line and (ii) modified color ZL 2  if area  918  is spaced apart from the line. 
       FIG. 98  illustrates a basketball IP structure  1300  containing OI structure  900  or, preferably, cell-containing OI structure  1100  incorporated into a U.S. collegiate basketball court to form a basketball-playing structure that provides assistance in making OB and three-point-shot eligibility determinations. Surface  102  consists of a rectangular IB area  1302  and an annular OB area  1304  directly surrounding IB area  1302 . IB area  1302  is defined inwardly by the inside edges of two opposite equal-width parallel straight baselines  1306 S and  1306 T (collectively “ 1306 ”) and the inside edges of two opposite equal-width parallel straight sidelines  1308 U and  1308 V (collectively “ 1308 ”) extending between baselines  1306 . Each line  1306  or  1308  is an open boundary line. Lines  1306  and  1308  together form a rectangular closed boundary line  1306 / 1308  whose inside edge is a closed boundary for area  1302 . 
     A straight midcourt line  1310  divides IB area  1302  into two equal-size rectangular half courts  1312 S and  1312 T. A center circle  1314  is concentric with the center of area  1302 . The basketball-playing structure includes two baskets  1316 S and  1316 T respectively attached to two backboards  1318 S and  1318 T situated above area  1302  respectively near baselines  1306 S and  1306 T and spaced equally apart from sidelines  1308 . 
     Each half court  1312 S or  1312 T has (a) a rectangular free-throw lane  1320 S or  1320 T located midway between sidelines  1308  and defined by baseline  1306 S or  1306 T, a straight free-throw line  1322 S or  1322 T parallel to line  1306 S or  1306 T, and two straight parallel lane lines  1324 S or  1324 T extending between, and perpendicular to, lines  1306 S and  1322 S or  1306 T and  1322 T, basket  1316 S or  1316 T being located above part of free-throw lane  1320 S or  1320 T near baseline  1306 S or  1306 T, (b) a semicircular free-throw shooting area  1326 S or  1326 T extending away from lane  1320 S or  1320 T and defined by line  1322 S or  1322 T and a semicircular back line  1328 S or  1328 T, (c) a restricted area  1330 S or  1330 T located within lane  1320 S or  1320 T below basket  1316 S or  1316 T and defined by a curved restricted-area line  1332 S or  1332 T and a straight line located largely below backboard  1318 S or  1318 T, and (d) a curved three-point (“3P”) line  1334 S or  1334 T located outside lane  1320 S or  1320 T and free-throw area  1326 S or  1326 T and extending to baseline  1306 S or  1306 T at two locations spaced equally apart from sidelines  1308 . Restricted-area line  1332 S or  1332 T and 3P line  1334 S or  1334 T each have a semicircular portion whose vertex is approximately concentric with the center of a vertical projection of basket  1316 S or  1316 T onto surface  102 . All finite-width lines, including boundary lines  1306  and  1308 , restricted-area lines  1332 S and  1332 T (collectively “ 1332 ”), and 3P lines  1334 S and  1334 T (collectively “ 1334 ”), are usually approximately 5 cm wide. 
     A basketball goes out of bounds if it impacts any of boundary lines  1306  and  1308 . The same applies to a basketball player. Hence, lines  1306  and  1308  are parts of OB area  1304 . The inside edge of each of lines  1306  and  1308  is its critical edge for determining whether object  104  embodied with a basketball or part, such as a shoe, of a basketball player impacting surface  102  at/near any of lines  1306  and  1308  is in or out of bounds. Each 3P line  1334 S or  1334 T has near (or inside) and far (or outside) edges respectively nearest to and farthest from its basket  1316 S or  1316 T. Two points are awarded for a basket made on a shot taken inside each 3P line  1334 S and  1334 T, i.e., in a two-point area  1336 S or  1336 T between line  1334 S or  1334 T and baseline  1306 S or  1306 T, at basket  1316 S or  1316 T. Three points are awarded for a basket made on an IB shot taken outside each line  1334 S or  1334 T at basket  1316 S or  1316 T provided that at least one shoe of the player shooting the basketball (or foot if the player is bare-footed) contacts the court behind line  1334 S or  1334 T immediately prior to the shot. Also, a shot at basket  1316 S or  1316 T is ineligible for three points, and is thus eligible only for two points, if any part, e.g., either shoe, of the shooter contacts line  1334 S or  1334 T or/and impacts surface  102  inside line  1334 S or  1334 T during the shot. For object  104  embodied with a shoe of a player, the far edge of each line  1334  is its critical edge for determining whether a shot qualifies as a 3P shot. 
     A narrow elongated straight part  1338 S or  1338 T of IB area  1302  directly along the inside edge of each baseline  1306 S or  1306 T forms, as highest CC location priority for lines  1306 , a composite VC inside-edge BLA area part. Each composite VC inside-edge BLA part  1338 S or  1338 T discontinuously consists of (a) a first end VC inside-edge BLA area part (or subpart)  1338 SU or  1338 TU lying fully along the part of baseline  1306 S or  1306 T extending between sideline  1308 U and the nearest end of 3P line  1334 S or  1334 T, (b) a central VC inside-edge BLA area part (or subpart)  1338 SC or  1338 TC lying fully along the part of baseline  1306 S or  1306 T extending between the opposite ends of 3P line  1334 S or  1334 T, and (c) a second end VC inside-edge BLA area part (or subpart)  1338 SV or  1338 TV lying fully along the part of baseline  1306 S or  1306 T extending between sideline  1308 V and the nearest end of 3P line  1334 S or  1334 T. Each VC inside-edge BLA part  1338 SU,  1338 SC,  1338 SV,  1338 TU,  1338 TC, or  1338 TV embodies a unit of SF zone  112 . A narrow elongated straight part  1340 U or  1340 V of area  1302  lying fully along the inside edge of each sideline  1308 U or  1308 V forms, as highest CC location priority for lines  1308 , a VC inside-edge SLA area part embodying a unit of zone  112 . VC inside-edge LA parts  1338 S and  1338 T (collectively “ 1338 ”) and  1340 U and  1340 V (collectively “ 1340 ”) form a rectangular annular VC inside-edge BV LA area portion  1342 . As highest CC location priority for 3P lines  1334 , a narrow curved part  1344 S or  1344 T of area  1302  lying fully along the far (or outside) edge of each line  1334 S or  1334 T, i.e., the edge farthest from basket  1316 S or  1316 T, forms a VC far-edge 3P LA area part embodying a unit of zone  112 . 
     Each baseline  1306  is, as next highest CC location priority for lines  1306 , a VC baseline area part embodying a unit of SF zone  892 . Each sideline  1308  is, as next highest CC location priority for lines  1308 , a VC sideline area part embodying a unit of zone  892 . Boundary lines  1306  and  1308  form a rectangular annular VC boundary line area  1346 . As next highest CC location priority for 3P lines  1334 , each line  1334  is a VC three-point-line (“3PL”) area part embodying a unit of zone  892 . 
     The FC part  1348  of IB area  1302  bounded by LA parts  1344 S,  1344 T,  1338 SU,  1338 SV,  1338 TU,  1338 TV, and  1340  embodies a unit of SF zone  114 . OB area  1304  is an FC area part embodying a unit of SF zone  894 . The FC remainder  1350 S or  1350 T of each two-point area  1336 S or  1336 T bounded by BLA part  1338 SC or  1338 TC and 3P line  1334 S or  1334 T embodies both (a) a unit of zone  114  for the unit of SF zone  112  embodied with part  1338 SC or  1338 TC and (b) a unit of zone  894  for the unit of SF zone  892  embodied with line  1334 S or  1334 T. These units of zones  114  and  894  embody the same FC SF zone. 
     A narrow elongated straight part  1352 S or  1352 T of OB area  1304  lying fully along the outside edge of each baseline  1306 S or  1306 T optionally forms a VC outside-edge BLA area part embodying a unit of SF zone  912 . A narrow elongated straight part  1354 U or  1354 V of area  1304  lying fully along the outside edge of each sideline  1308 U or  1308 V optionally forms a VC outside-edge SLA area part embodying a unit of zone  912 . VC outside-edge LA parts  1352 S and  1352 T (collectively “ 1352 ”) and  1354 U and  1354 V (collectively “ 1354 ”) form a rectangular annular VC outside-edge BV LA area portion  1356 . A narrow curved elongated part  1358 S or  1358 T of IB area  1302  lying fully along the near (or inside) edge of each 3P line  1334 S or  1334 T, i.e., the edge nearest basket  1316 S or  1316 T, optionally forms a VC near-edge 3P LA area part embodying a unit of zone  912 . 
     For the preceding options, the resultant smaller FC remainder  1360 S or  1360 T of each two-point area  1336 S or  1336 T, i.e., the part bounded by BLA part  1338 SC or  1338 TC and 3P LA part  1358 S or  1358 T, embodies both (a) a unit of SF zone  114  for the unit of SF zone  112  embodied with BLA part  1338 SC or  1338 TC and (b) a unit of SF zone  914  for the unit of SF zone  912  embodied with 3P LA part  1358 S or  1358 T. These units of zones  114  and  914  embody the same FC SF zone. The annular FC remainder  1362  of OB area  1304  bounded by LA area portion  1356  embodies a unit of zone  914 . 
     A VC structure part of IP structure  1300  extends to surface  102  at each of lines  1306 ,  1308 , and  1334  and VC LA area parts  1338 ,  1340 ,  1344 S and  1344 T (collectively “ 1344 ”),  1352 ,  1354 , and  1358 S and  1358 T (collectively “ 1358 ”). In particular, IP structure  1300  includes (a) composite VC inside-edge BLA structure consisting of two composite VC inside-edge BLA structure parts extending to surface  102  respectively at composite inside-edge BLA area parts  1338 , (b) VC inside-edge SLA structure consisting of two VC inside-edge SLA structure parts respectively formed with two units of VC region  106  and extending to surface  102  respectively at inside-edge SLA area parts  1340 , (c) VC baseline structure consisting of two VC baseline structure parts respectively formed with two units of VC region  886  and extending to surface  102  respectively at baselines  1306 , (d) VC sideline structure consisting of two VC sideline structure parts respectively formed with two units of region  886  and extending to surface  102  respectively at sidelines  1308 , (e) VC outside-edge BLA structure consisting of two VC outside-edge BLA structure parts respectively formed with two units of VC region  906  and extending to surface  102  respectively at outside-edge BLA area parts  1352 , (f) VC outside-edge SLA structure consisting of two VC outside-edge SLA structure parts respectively formed with two units of region  906  and extending to surface  102  respectively at outside-edge SLA area parts  1354 , (g) VC far-edge 3P LA structure consisting of two VC far-edge 3P LA structure parts respectively formed with two units of region  106  and extending to surface  102  respectively at far-edge 3P LA area parts  1344 , (h) VC 3PL structure consisting of two VC 3PL structure parts respectively formed with two units of region  886  and extending to surface  102  respectively at 3P lines  1334 , and (i) VC near-edge 3P LA structure consisting of two VC near-edge 3P LA structure parts respectively formed with two units of region  906  and extending to surface  102  respectively at near-edge 3P LA area parts  1358 . 
     The composite VC inside-edge BLA structure consists of (i) two first end VC inside-edge BLA structure parts (or subparts) respectively formed with two units of VC region  106  and extending to surface  102  respectively at first end inside-edge BLA area parts  1338 SU and  1338 TU, (i) two central VC inside-edge BLA structure parts (or subparts) respectively formed with two units of region  106  and extending to surface  102  respectively at central inside-edge BLA area parts  1338 SC and  1338 TC, and (iii) two second end VC inside-edge BLA structure parts (or subparts) respectively formed with two units of region  106  and extending to surface  102  respectively at second end inside-edge BLA area parts  1338 SV and  1338 TV. 
     Each VC inside-edge BLA structure part normally appears along its BLA area part  1338 S or  1338 T as a PP BV color AIS or AIT embodying PP color A. Each VC inside-edge SLA structure part normally appears along its SLA area part  1340 U or  1340 V as a PP BV color AIU or AIV embodying color A. Each VC inside-edge BLA or SLA structure part is thus a VC inside-edge BV LA structure part normally appearing along its LA area part  1338 S,  1338 T,  1340 U, or  1340 V as color AIS, AIT, AIU, or AIV. Each VC baseline structure part normally appears along its baseline  1306 S or  1306 T as an AD BV color BBS or BBT embodying AD color B. Each VC sideline structure part normally appears along its sideline  1308 U or  1308 V as an AD BV color BBU or BBV embodying color B. Hence, each VC baseline or sideline structure part is a VC BV line structure part normally appearing along its boundary line  1306 S,  1306 T,  1308 U, or  1308 V as color BBS, BBT, BBU, or BBV. Each VC outside-edge BLA structure part normally appears along its BLA area part  1352 S or  1352 T as an FR BV color COS or COT embodying FR color C. Each VC outside-edge SLA structure part normally appears along its SLA area part  1354 U or  1354 V as an FR BV color COU or COV embodying color C. Each VC outside-edge BLA or SLA structure part is therefore a VC outside-edge BV LA structure part normally appearing along its LA area part  1352 S,  1352 T,  1354 U, or  1354 V as color COS, COT, COU, or COV. 
     IDVC portion  138  of each VC inside-edge BV LA structure part responds to object  104  impacting LA area part  1338 S,  1338 T,  1340 U, or  1340 V of that structure part at OC area  116  as described above for the general OI structure without intelligent control with changed color X embodied as a changed BV color XIS, XIT, XIU, or XIV materially different from PP BV color AIS, AIT, AIU, or AIV. IDVC portion  926  of each VC BV line structure part responds to object  104  impacting boundary line  1306 S,  1306 T,  1308 U, or  1308 V of that structure part at OC area  896  as prescribed for the general OI structure without intelligent control with altered color Y embodied as an altered BV color YBS, YBT, YBU, or YBV materially different from AD BV color BBS, BBT, BBU, or BBV. An FR IDVC portion of each VC outside-edge BV LA structure part responds to object  104  impacting LA area part  1352 S,  1352 T,  1354 U, or  1354 V at OC area  916  of that structure part as prescribed for the general OI structure without intelligent control with modified color Z embodied as a modified BV color ZOS, ZOT, ZOU, or ZOV materially different from FR BV color COS, COT, COU, or COV. 
     Each VC far-edge 3P LA structure part normally appears along its LA area part  1344 S or  1344 T as a PP three-point-line-vicinity (“3PLV”) color A3S or A3T embodying PP color A. Each VC 3PL structure part normally appears along its 3P line  1334 S or  1334 T as an AD 3PLV color B3S or B3T embodying AD color B. Each VC near-edge 3P LA structure part normally appears along its LA area part  1358 S or  1358 T as an FR 3PLV color C3S or C3T embodying FR color C. 
     IDVC portion  138  of each VC far-edge 3P LA structure part can respond to object  104  impacting LA area part  1344 S or  1344 T of that structure part at OC area  116  as described above for the general OI structure without intelligent control with changed color X embodied as a changed 3PLV color X3S or X3T materially different from PP 3PLV color A3S or A3T. IDVC portion  926  of each VC 3PL structure part can respond to object  104  impacting 3P line  1334 S or  1334 T of that structure part at OC area  896  as prescribed for the general OI structure without intelligent control with altered color Y embodied as an altered 3PLV color Y3S or Y3T materially different from AD 3PLV color B3S or B3T. An FR IDVC portion of each VC near-edge 3P LA structure part can respond to object  104  impacting LA area part  1358 S or  1358 T of that structure part at OC area  916  as prescribed for the general OI structure without intelligent control with modified color Z embodied as a modified 3PLV color Z3S or Z3T materially different from FR 3PLV color C3S or C3T. 
     IP structure  1300  usually contains CC controller  1114  for implementing one of IP structures  1110  and  1170  or CC controller  1134  for implementing one of IP structure  1130  and  1200 . Controller  1114 / 1134  operates as an intelligent controller for making 3P-shot qualification determinations. If an impact at or near either 3P line  1334  meets the PP, AD, FR, or CP TH impact criteria, controller  1114 / 1134  determines whether the PP, AD, FR, or CP supplemental impact information meets the PP, AD, FR, or CP supplemental impact criteria for surface  102  being impacted by a person&#39;s shoe, specifically a basketball shoe, embodying object  104 . Color change occurs along one or more of lines  1334 , far-edge 3P LA parts  1344 , and near-edge 3P LA parts  1358  only when the impact characteristics meet the PP, AD, FR, or CP expanded impact criteria for a person&#39;s shoe impacting surface  102 . Impact of a basketball on either of lines  1334  or any of adjoining parts  1344  and  1358  usually does not cause a color change. 
     3P shots in each half court  1312 S or  1312 T are almost always taken with the shooter generally facing basket  1316 S or  1316 T and with the shooter&#39;s shoes generally pointed toward basket  1316 S or  1316 T. Taking this into account, the PP, AD, FR, or CP supplemental impact criteria can require that each shoe be generally pointed toward basket  1316 S or  1316 T. No color change occurs if at least one shoe is pointing away from basket  1316 S or  1316 T, thereby largely avoiding color undesired changes due to non-shooting activities when a shoe is pointed away from basket  1316 S or  1316 T. More particularly, letting the contact area for a shoe on surface  102  have a longitudinal axis defined, e.g., as a straight line extending between the area&#39;s two most distant points so as to match a straight line extending between the shoe&#39;s two most distant points, the PP, AD, FR, or CP supplemental impact criteria for 3P shot attempts can require that the angle between the longitudinal axis of the shoe&#39;s contact area and a radial line extending from the vertex of associated 3P line  1334 S or  1334 T be no more than a selected value, usually 30°, potentially 20° or even 15°, with the shoe pointed toward basket  1316 S or  1316 T. Implementing the PP, AD, FR, and CP supplemental impact criteria in this way substantially reduces the occurrences of unneeded/unwanted color changes when a shoe of a player not shooting the basketball impacts any of 3P lines  1334  and 3P LA parts  1344  and  1358 . 
     The following specifically occurs when controller  1114 / 1134  is implemented as an intelligent controller for assistance in making 3P-shot qualification determinations. Controller  1114 / 1134  and IDVC portion  138  of each VC far-edge 3P LA structure part respond to object  104  impacting LA area part  1344 S or  1344 T of that structure part at OC area  116  as described above for the general OI structure with intelligent control with changed color X embodied as changed 3PLV color X3S or X3T. Controller  1114 / 1134  and IDVC portion  926  of each VC 3PL structure part respond to object  104  impacting 3P line  1334 S or  1334 T of that structure part at OC area  896  as prescribed for the general OI structure with intelligent control with altered color Y embodied as altered 3PLV color Y3S or Y3T. Controller  1114 / 1134  and an FR IDVC portion of each VC near-edge 3P LA structure part respond to object  104  impacting LA area part  1358 S or  1358 T of that structure part at OC area  916  as prescribed for the general OI structure with intelligent control with modified color Z embodied as modified 3PLV color Z3S or Z3T. 
     Controller  1114 / 1134  preferably uses the location-dependent version of the CC capability to control the color changing so that IDVC portion  138  of the VC far-edge 3P LA structure part for each 3P line  1334 S or  1334 T appears as (i) a first changed color X3S 1  or X3T 1  if print area  118  of VC far-edge 3P LA part  1344 S or  1344 T adjoins line  1334 S or  1334 T and (ii) a second changed color X3S 2  or X3T 2  different from color X3S 1  or X3T 1  if area  118  of part  1344 S or  1344 T is spaced apart from line  1334 S or  1334 T. During a shot, the appearance of area  118  of the far-edge 3P LA structure part for each line  1334 S or  1334 T as color X3S 1  or X3T 1 , preferably the same color X i , indicates that the shot fails to qualify as a 3P shot attempt because having area  118  of part  1344 S or  1344 T adjoin line  1334 S or  1334 T means that a shoe of the shooter impacted line  1334 S or  1334 T whereas the appearance of that LA structure part as color X3S 2  or X3T 2 , preferably the same color X 2 , indicates that the shot qualifies as a 3P shot because having area  118  of part  1344 S or  1344 T be spaced apart from line  1334 S or  1334 T means that the shooter&#39;s shoe was suitably behind line  1334 S or  1334 T at the beginning of the shot. A viewer, e.g., an official, can nearly always determine whether a shot qualifies as a 3P shot by simply examining the color of area  118 . 
     It is usually sufficient for controller  1114 / 1134  to operate as a duration controller for making OB determinations in IP structure  1300 . If controller  1114 / 1134  is to operate as an intelligent controller for making OB determinations, the inside-edge BV LA structure parts, their area parts  1338  and  1340 , the BV line structure parts, their lines  1306  and  1308 , the outside-edge BV LA structure parts, and their area parts  1352  and  1354  interact with controller  1114 / 1134  the same as the VC far-edge 3P LA structure parts, their area parts  1344 , the 3PL structure parts, their lines  1334 , the near-edge 3P LA structure parts, and their area parts  1358  respectively interact with controller  1114 / 1134  operating as an intelligent controller subject to the PP, AD, FR, and CP supplemental impact criteria being criteria for a basketball and/or a person&#39;s shoe, specifically a basketball shoe, impacting surface  102 . 
     The invention&#39;s CC capability can be implemented along each restricted-area line  1332 S or  1332 T to assist in determining whether both shoes of a defensive player are outside restricted area  1330 S or  1330 T so that the player is eligible for taking a charge by an offensive player. Inasmuch as having either shoe on or inside line  1332 S or  1332 T for the defensive player makes that player ineligible to take a charge, a narrow curved part of IB area  1302  extending fully along the far (or outside) edge of each line  1332 S or  1332 T, i.e., the edge farthest from basket  1316 S or  1316 T, embodies a unit of SF zone  112 . Each line  1332 S or  1332 T preferably embodies a unit of SF zone  892 . A narrow curved part of area  1302  extending fully along the near (or inside) edge of each line  1332 S or  1332 T, i.e., the edge nearest basket  1316 S or  1316 T, optionally embodies a unit of SF zone  912 . Controller  1114 / 1134  preferably operates as an intelligent controller in regard to lines  1332  so that color change along one or more of each line  1332  and the adjoining area portions occurs only when the impact characteristics meet the PP, AD, FR, or CP expanded impact criteria for a shoe. 
     Instead of having color change occur automatically when the PP, AD, FR, or CP expanded impact criteria are met, color change can be delayed to occur only in response to external instruction provided, e.g., by a basketball official. In this way, a non-shooting or non-charging activity that meets the PP, AD, FR, or CP expanded impact criteria can be prevented from causing a color change. 
       FIG. 99  illustrates a volleyball IP structure  1380  containing OI structure  900  or, preferably, cell-containing OI structure  1100 , incorporated into a U.S. collegiate volleyball court to form a volleyball-playing structure that provides assistance in making service end-line violation, OB, and attack-line violation determinations. Surface  102  consists of a rectangular IB area  1382  and an annular OB area  1384  directly surrounding IB area  1382 . IB area  1382  is defined inwardly by the outside edges of two opposite equal-width parallel straight end lines  1386 S and  1386 T (collectively “ 1386 ”) and the outside edges of two opposite equal-width parallel straight side lines  1388 U and  1388 V (collectively “ 1388 ”) extending between end lines  1386 . Each line  1386  or  1388  is an open boundary line. Lines  1386  and  1388  together form a rectangular closed boundary line  1386 / 1388  whose outside edge is a closed boundary for area  1382 . 
     IP structure  1380  further includes an elevated volleyball net  1390  situated above a straight centerline  1392  extending parallel to end lines  1386  and spaced equally apart from them to divide IB area  1382  into two rectangular half courts  1394 S and  1394 T. Each half court  1394 S or  1394 T has a straight attack line  1396 S or  1396 T extending between side lines  1388  parallel to end lines  1386 . Each attack line  1396 S or  1396 T is located between centerline  1392  and end line  1386 S or  1386 T for dividing half court  1394 S or  1394 T into (a) a rectangular back court  1398 S or  1398 T extending to end line  1386 S or  1386 T and (b) a rectangular front court  1400 S or  1400 T extending to centerline  1392 . All finite-width lines, including boundary lines  1386  and  1388  and attack lines  1396 S and  1396 T (collectively “ 1396 ”), are usually approximately 5 cm wide. Each attack line  1396  has near and far edges respectively nearest to and farthest from centerline  1392 . 
     A volleyball point begins with an effort by a player, the server, positioned in a service zone behind end line  1386  to hit a volleyball over net  1390  using one hand or arm. A service end-line violation occurs if either foot, i.e., either shoe of the server, impacts back court  1398 S or  1398 T, including end line  1386 S or  1386 T, before the volleyball leaves the server&#39;s hand or arm. For object  104  embodied with a shoe of a player, the outside edge of each line  1386  is its critical edge for determining whether a service end-line violation has occurred. A volleyball is “in” if it contacts any of boundary lines  1386  and  1388  and is “out” only if it contacts surface  102  fully outside lines  1386  and  1388 . Accordingly, lines  1386  and  1388  are parts of IB area  1382 . The outside edge of each of lines  1386  and  1388  is its critical edge for determining whether object  104  embodied with a volleyball impacting surface  102  at/near any of lines  1386  and  1388  is “in” or “out”. 
     Each team playing volleyball consists of six players, three of which are designated as back-court players for each volleyball point. A back-court player in half court  1394 S or  1394 T is permitted to attack (hit forward) a volleyball fully above the net height at the instant of contact only if both of the player&#39;s feet, specifically both shoes, are behind attack line  1396 S or  1396 T immediately prior to attacking the volleyball. The back-court player may be elevated above surface  102 , including above front court  1400 S or  1400 T, during the attack provided that neither foot, i.e., neither shoe, impacts front court  1400 S or  1400 T before the attack is completed. For object  104  embodied with a shoe of a player, the far edge of each attack line  1396  is its critical edge for determining whether an attack-line violation has occurred. 
     A narrow elongated straight part  1402 S or  1402 T of OB area  1384  lying fully along the outside edge of each end line  1386 S or  1386 T forms, as highest CC location priority for determining service end-line violations and making OB determinations for lines  1386 , a VC outside-edge ELA area part embodying a unit of SF zone  112 . A narrow elongated straight part  1404 U or  1404 V of area  1384  lying fully along the outside edge of each side line  1388 U or  1388 V forms, as highest CC location priority for making OB determinations for lines  1388 , a VC outside-edge SLA area part embodying a unit of zone  112 . VC outside-edge LA parts  1402 S and  1402 T (collectively “ 1402 ”) and  1404 U and  1404 V (collectively “ 1404 ”) form a VC outside-edge BV LA area portion  1406 . As highest CC location priority for attack lines  1396 , a narrow elongated straight part  1408 S or  1408 T of IB area  1382  lying fully along the far edge of each line  1396 S or  1396 T, i.e., the edge farthest from centerline  1392 , forms a VC far-edge ALA area part embodying a unit of zone  112 . 
     Each end line  1386 S or  1386 T forms, as next highest CC location priority for determining service end-line violations and making OB determinations for lines  1386 , a VC end-line area part  1410 S or  1410 T embodying a unit of SF zone  892 . Each side line  1388 U or  1388 V forms, as next highest CC location priority for making OB determinations for lines  1388 , a VC side-line area part  1412 U or  1412 V embodying a unit of zone  892 . Boundary-line parts  1410 S and  1410 T (collectively “ 1410 ”) and  1412 U and  1412 V (collectively “ 1412 ”) form a rectangular annular VC boundary line area  1414 . As next highest CC location priority for attack lines  1396 , each line  1396 S or  1396 T is a VC attack-line area part  1416 S or  1416 T embodying a unit of zone  892 . 
     The annular FC remainder  1418  of OB area  1384  beyond boundary line area  1414  embodies a unit of SF zone  114 . The rectangular FC remainder  1420 S or  1420 T of back court  1398 S or  1398 T bounded by end line  1386 S or  1386 T, ALA part  1408 S or  1408 T, and the intervening parts of side lines  1388  embodies both (a) a unit of zone  114  for the unit of SF zone  112  embodied with part  1408 S or  1408 T and (b) a unit of SF zone  894  for the units of SF zone  892  embodied with end line  1386 S or  1386 T and side lines  1388 . Each pair of units of zones  114  and  894  embody the same FC SF zone. The rectangular FC remainder  1422  of front courts  1400 S and  1400 T bounded by attack lines  1396  and the intervening parts of side lines  1388  embodies a unit of zone  894 . 
     A narrow elongated straight part  1424 S or  1424 T of back court  1398 S or  1398 T lying fully along the inside edge of each end line  1386 S or  1386 T optionally forms, for determining service end-line violations and making OB determinations for lines  1386 , a VC inside-edge ELA area part embodying a unit of SF zone  912 . A narrow elongated straight part  1426 U or  1426 V of IB area  1382  directly along the inside edge of each side line  1388 U or  1388 V optionally forms, for making OB determinations for lines  1388 , a composite VC inside-edge SLA area part. Each composite VC inside-edge SLA part  1426 U or  1426 V discontinuously consists of (a) a first end VC inside-edge SLA area part (or subpart)  1426 US or  1426 VS lying fully along the part of side line  1388 U or  1388 V between inside-edge ELA part  1424 S and far-edge ALA part  1408 S, (b) a central VC inside-edge SLA area part (or subpart)  1426 UC or  1426 VC lying fully along the part of side line  1388 U or  1388 V between attack lines  1396 , and (c) a second end VC inside-edge SLA area part (or subpart)  1426 UT or  1426 VT lying fully along the part of side line  1388 U or  1388 V between inside-edge ELA part  1424 T and far-edge ALA part  1408 T. Each VC inside-edge SLA part  1426 US,  1426 UC,  1426 UT,  1426 VS,  1426 VC, or  1426 VT embodies a unit of zone  912 . Inside-edge LA parts  1424 S and  1424 T (collectively “ 1424 ”) and  1426 U and  1426 V (collectively “ 1426 ”) discontinuously form a rectangular annular VC inside-edge BV LA area portion  1428 . A narrow elongated straight part  1430 S or  1430 T of front court  1400 S or  1400 T lying fully along the near edge of each attack line  1396 S or  1396 T optionally forms a VC near-edge ALA area part embodying a unit of zone  912 . 
     For the preceding options, the resultant smaller rectangular FC remainder  1432 S or  1432 T of each back court  1398 S or  1398 T, i.e., the part bounded by ALA part  1408 S or  1408 T, ELA part  1424 S or  1424 T, and SLA parts  1426 US and  1426 VS or  1426 UT and  1426 VT, embodies both (a) a unit of SF zone  114  for the unit of SF zone  112  embodied with ALA part  1408 S or  1408 T and (b) a unit of SF zone  914  for the units of SF zone  912  embodied with ELA part  1424 S or  1424 T and SLA parts  1426 US and  1426 VS or  1426 UT and  1426 VT. These units of zones  114  and  914  embody the same FC SF zone. The resultant smaller rectangular FC remainder  1434  of front courts  1400 S and  1400 T, i.e., the part bounded by LA parts  1430 S,  1430 T,  1426 UC, and  1426 VC, embodies a unit of zone  914 . 
     Similar to VC singles HA area portions  1274  in tennis IP structure  1260 , VC outside-edge SLA parts  1404  may extend only partway, usually at least three fourths of the way, from each end line  1386  to centerline  1392 . In particular, each part  1404  splits into two parts (or subparts) each extending from an end line  1386  past closest attack line  1396  partway to centerline  1392 . Each VC side-line part  1412  continues to lie fully along its SLA part  1404  and likewise splits into two parts each extending from an end line  1386  past closest attack line  1396  partway to centerline  1392 . The same applies to each VC inside-edge SLA part  1426 . Each VC outside-edge BV LA area portion  1406 , VC boundary line area  1414 , or VC inside-edge BV LA area portion  1428  correspondingly splits into two ␣-shaped portions each extending partway from an end line  1386  past closest attack line  1396  to centerline  1392 . 
     A VC structure part of IP structure  1380  extends to surface  102  at each of VC line area parts  1410 ,  1412 , and  1416 S and  1416 T (collectively “ 1416 ”) and VC LA area parts  1402 ,  1404 ,  1408 S and  1408 T (collectively “ 1408 ”),  1424 ,  1426 , and  1430 S and  1430 T (collectively “ 1430 ”). Structure  1380  specifically includes (a) VC outside-edge ELA structure consisting of two VC outside-edge ELA structure parts respectively formed with two units of VC region  106  and extending to surface  102  respectively at outside-edge ELA area parts  1402 , (b) VC outside-edge SLA structure consisting of two VC outside-edge SLA structure parts extending to surface  102  respectively at outside-edge SLA area parts  1404 , (c) VC end-line structure consisting of two VC end-line structure parts respectively formed with two units of VC region  886  and extending to surface  102  respectively at end-line area parts  1410  or, equivalently, end lines  1386 , (d) VC side-line structure consisting of two VC side-line structure parts extending to surface  102  respectively at side-line area parts  1412  or, equivalently, side lines  1388  at least partly along their lengths, (e) VC inside-edge ELA structure consisting of two VC inside-edge ELA structure parts respectively formed with two units of VC region  906  and extending to surface  102  respectively at inside-edge ELA area parts  1424 , (f) composite VC inside-edge SLA structure consisting of two VC inside-edge SLA structure parts extending to surface  102  respectively at inside-edge SLA area parts  1426 , (g) VC far-edge ALA structure consisting of two VC far-edge ALA structure parts respectively formed with two units of region  106  and extending to surface  102  respectively at far-edge ALA area parts  1408 , (h) VC attack-line structure consisting of two VC attack-line structure parts respectively formed with two units of region  886  and extending to surface  102  respectively at VC attack-line area parts  1416  or, equivalently, attack lines  1396 , and (i) VC near-edge ALA structure consisting of two VC near-edge ALA structure parts respectively formed with two units of region  906  and extending to surface  102  respectively at near-edge ALA area parts  1430 . 
     Each VC outside-edge SLA structure part is formed with a unit of VC region  106  if each outside-edge SLA area part  1404  is continuous (one piece). If each area part  1404  is split into two parts, each VC outside-edge SLA structure part splits into two structure parts (or subparts) each formed with a unit of region  106 . Each VC side-line structure part is formed with a unit of VC region  886  if each side-line area part  1412  is continuous. If each area part  1412  is split into two parts, each VC side-line structure part splits into two structure parts (or subparts) each formed with a unit of region  886 . The composite VC inside-edge SLA structure consists of (i) two first end VC inside-edge SLA structure parts (or subparts) respectively formed with two units of VC region  906  and extending to surface  102  respectively at first end inside-edge SLA area parts  1426 US and  1426 VS, (ii) two central VC inside-edge SLA structure parts (or subparts) extending to surface  102  respectively at central inside-edge SLA area parts  1426 UC and  1426 VC, and (iii) two second end VC inside-edge SLA structure parts (or subparts) respectively formed with two units of region  906  and extending to surface  102  respectively at second end inside-edge SLA area parts  1426 UT and  1426 VT. Each central VC inside-edge SLA structure part is formed with a unit of region  906  if each central inside-edge SLA area part  1426 UC or  1426 VC is continuous. If each area part  1426 UC or  1426 VC is split into two parts, each central inside-edge SLA structure part splits into two structure parts (or subparts) each formed with a unit of region  906 . 
     Each VC outside-edge ELA structure part normally appears along its ELA area part  1402 S or  1402 T as a PP BV color AOS or AOT embodying PP color A. Each VC outside-edge SLA structure part normally appears along its SLA area part  1404 U or  1404 V as a PP BV color AOU or AOV embodying color A. Hence, each VC outside-edge ELA or SLA structure part is a VC outside-edge BV LA structure part normally appearing along its LA area part  1402 S,  1402 T,  1404 U, or  1404 V as color AOS, AOT, AOU, or AOV. Each VC end-line structure part normally appears along its area part  1410 S or  1410 T or, equivalently, end line  1386 S or  1386 T as an AD BV color BBS or BBT embodying AD color B. Each VC side-line structure part normally appears along its area part  1412 U or  1412 V or, equivalently, its side line  1388 U or  1388 V as an AD BV color BBU or BBV embodying color B. Hence, each VC end-line or side-line structure part is a VC BV line structure part normally appearing along its area part  1410 S,  1410 T,  1412 U, or  1412 V or, equivalently, boundary line  1386 S,  1386 T,  1388 U or  1388 V as color BBS, BBT, BBU, or BBV. Each VC inside-edge ELA structure part normally appears along its ELA area part  1424 S or  1424 T as an FR BV color CIS or CIT embodying FR color C. Each VC inside-edge SLA structure part normally appears along its SLA area part  1426 U or  1426 V as an FR BV color CIU or CIV embodying color C. Each VC inside-edge ELA or SLA structure part is thus a VC inside-edge BV LA structure part normally appearing along its LA area part  1424 S,  1424 T,  1426 U, or  1426 V as FR BV color CIS, CIT, CIU, or CIV. 
     IDVC portion  138  of each VC outside-edge BV LA structure part responds to object  104  impacting LA area part  1402 S,  1402 T,  1404 U, or  1404 V of that structure part at OC area  116  as described above for the general OI structure without intelligent control with changed color X embodied as a changed BV color XOS, XOT, XOU, or XOV materially different from PP BV color AOS, AOT, AOU, or AOV. IDVC portion  926  of each VC BV line structure part responds to object  104  impacting line area part  1410 S,  1410 T,  1412 U, or  1412 V or, equivalently, boundary line  1386 S,  1386 T,  1388 U, or  1388 V of that structure part at OC area  896  as prescribed for the general OI structure without intelligent control with altered color Y embodied as an altered BV color YBS, YBT, YBU, or YBV materially different from AD BV color BBS, BBT, BBU, or BBV. An FR IDVC portion of each VC inside-edge BV LA structure part responds to object  104  impacting LA area part  1424 S,  1424 T,  1426 U, or  1426 V of that structure part at OC area  916  as prescribed for the general OI structure without intelligent control with modified color Z embodied as a modified BV color ZIS, ZIT, ZIU, or ZIV materially different from FR BV color CIS, CIT, CIU, or CIV. 
     Each VC far-edge ALA structure part normally appears along its LA area part  1408 S or  1408 T as a PP attack-line-vicinity (“ALV”) color AAS or AAT embodying PP color A. Each VC attack-line structure part normally appears along its area part  1416 S or  1416 T or, equivalently, attack line  1396 S or  1396 T as an AD ALV color BAS or BAT embodying AD color B. Each VC near-edge ALA structure part normally appears along its LA area part  1430 S or  1430 T as an FR ALV color CAS or CAT embodying FR color C. 
     IDVC portion  138  of each VC far-edge ALA structure part can respond to object  104  impacting ALA area part  1408 S or  1408 T of that structure part at OC area  116  as described above for the general OI structure without intelligent control with changed color X embodied as a changed ALV color XAS or XAT materially different from PP ALV color AAS or AAT. IDVC portion  926  of each VC attack-line structure part can respond to object  104  impacting attack-line area part  1416 S or  1416 T of that structure part at OC area  896  as prescribed for the general OI structure without intelligent control with altered color Y embodied as an altered ALV color YAS or YAT materially different from AD ALV color BAS or BAT. An FR IDVC portion of each VC near-edge ALA structure part can respond to object  104  impacting ALA area part  1430 S or  1430 T of that structure part at OC area  916  as prescribed for the general OI structure without intelligent control with modified color Z embodied as a modified ALV color ZAS or ZAT materially different from FR ALV color CAS or CAT. 
     IP structure  1380  usually contains CC controller  1114  for implementing one of IP structures  1110  and  1170  or CC controller  1134  for implementing one of IP structures  1130  and  1200 . Controller  1114 / 1134  operates as an intelligent controller for making attack-line violation determinations. If an impact at or near either attack line  1396  meets the PP, AD, FR, or CP TH impact criteria, controller  1114 / 1134  determines whether the PP, AD, FR, or CP supplemental impact information meets the PP, AD, FR, or CP supplemental impact criteria for surface  102  being impacted by a person&#39;s shoe, specifically a volleyball shoe, embodying object  104 . Color change occurs along one or more of attack lines  1396 , far-edge ALA parts  1408 , and near-edge ALA parts  1430  only when the impact characteristics meet the PP, AD, FR, or CP expanded impact criteria for a person&#39;s shoe impacting surface  102 . Impact of a volleyball on any of lines  1396  and adjoining parts  1408  and  1430  usually does not cause a color change. 
     Similar to 3P shots in basketball, attacks by a back-court player almost always occur with the back-court attacker generally facing net  1390  and with the attacker&#39;s shoes generally pointed toward net  1390 . Taking this into account, the PP, AD, FR, or CP supplemental impact criteria can require that each shoe be generally pointed toward net  1390 . No color change occurs if at least one shoe is pointing away from net  1390 , thereby largely avoiding color undesired changes due to non-attacking activities when a shoe is pointed away from net  1390 . More particularly, letting the contact area for a shoe on surface  102  have a longitudinal axis defined, e.g., as a straight line extending between the area&#39;s two most distant points so as to match a straight line extending between the shoe&#39;s two most distant points, the PP, AD, FR, or CP supplemental impact criteria for back-court attacks can require that the angle between the longitudinal axis of the shoe&#39;s contact area and a line extending perpendicular to net  1390  be no more than a selected value, usually 40°, potentially 30° or even 20°, with the shoe pointed toward net  1390 . Implementing the PP, AD, FR, and CP supplemental impact criteria in this way substantially reduces the occurrences of unneeded/unwanted color changes when a shoe of a player not attacking the volleyball, e.g., a player whose back is temporarily facing net  1390 , impacts any of attack lines  1396  and ALA parts  1408  and  1424 . 
     The following specifically occurs when controller  1114 / 1134  is implemented as an intelligent controller for assistance in determining attack-line violations. Controller  1114 / 1134  and IDVC portion  138  of each VC far-edge ALA structure part respond to object  104  impacting ALA area part  1408 S or  1408 T of that structure part at OC area  116  as described above for the general OI structure with intelligent control with changed color X embodied as changed ALV color XAS or XAT. Controller  1114 / 1134  and IDVC portion  926  of each VC attack-line structure part respond to object  104  impacting attack-line area part  1416 S or  1416 T of that structure part at OC area  896  as prescribed for the general OI structure with intelligent control with altered color Y embodied as altered ALV color YAS or YAT. Controller  1114 / 1134  and an FR IDVC portion of each VC near-edge ALA structure part respond to object  104  impacting ALA area part  1430 S or  1430 T of that structure part at OC area  916  as prescribed for the general OI structure with intelligent control with modified color Z embodied as modified ALV color ZAS or ZAT. 
     Controller  1114 / 1134  preferably uses the location-dependent version of the CC capability to control the color changing so that IDVC portion  138  of the VC far-edge ALA structure part for each attack line  1396 S or  1396 T appears as (i) a first changed color XAS 1  or XAT 1  if print area  118  of VC far-edge ALA part  1408 S or  1408 T adjoins line  1396 S or  1396 T and (ii) a second changed color XAS 2  or XAT 2  different from color XAS 1  or XAT 1  if area  118  of part  1408 S or  1408 T is spaced apart from line  1396 S or  1396 T. During a back-court attack, the appearance of area  118  of the far-edge ALA structure part for each line  1396 S or  1396 T as color XAS 1  or XAT 1 , preferably the same color X 1 , indicates an attack-line violation because having area  118  of area part  1408 S or  1408 T adjoin line  1396 S or  1396 T means that a shoe of the attacker improperly impacted line  1396 S or  1396 T whereas the appearance of that LA structure part as color XAS 2  or XAT 2 , preferably the same color X 2 , indicates that the absence of an attack-line violation because having area  118  of part  1408 S or  1408 T be spaced apart from line  1396 S or  1396 T means that the attacker&#39;s shoe was suitably behind line  1396 S or  1396 T at the beginning of the attack. A viewer, e.g., an official, can nearly always determine whether an attack-line violation occurred by simply examining the color of area  118 . 
     It is usually sufficient for controller  1114 / 1134  to operate as a duration controller for making service end-line violation and OB determinations in IP structure  1380 . If controller  1114 / 1134  is to operate as an intelligent controller for making service end-line violation and OB determinations, the outside-edge BV LA structure parts, their area parts  1402  and  1404 , the BV line structure parts, their area parts  1410  and  1412 , the inside-edge BV LA structure parts, and their area parts  1424  and  1426  interact with controller  1114 / 1134  the same as the far-edge ALA structure parts, their area parts  1408 , the attack-line structure parts, their lines  1416 , the near-edge ALA structure parts, and their area parts  1430  respectively interact with controller  1114 / 1134  operating as an intelligent controller subject to the PP, AD, FR, and CP supplemental impact criteria being criteria for a volleyball impacting surface  102 . This includes using the location-dependent version of the CC capability for controlling the color changing in OB determinations. 
     Each FC area part adjoining a non-line VC area portion in IP structures  1300  and  1380  of  FIGS. 98 and 99  is usually the same color as the normal-state color of the VC area portion, at least along the interface between the FC and VC area portions. If an FC area part adjoins two adjoining VC non-line area portions, the VC non-line area portions are usually the same normal-state color which is the color of the FC area part, at least along the interface between the FC area part and each VC non-line area portion. 
       FIG. 100  illustrates an IP structure  1440  containing OI structure  900  or, preferably, cell-containing OI structure  1100 , incorporated into a field used for U.S. football to form a football-playing structure that provides assistance in determining where a football or a football player impacts the football field at/near its boundary. Object  104  is usually a football or a shoe of a football player but can be other parts of the player&#39;s body, including the clothes typically a football uniform worn by the player. Football IP structure  1440  applies to Canadian football by increasing the goal-line-to-goal-line dimension by 10% and doubling the end-zone width. 
     Surface  102  consists of a rectangular grass IB area  1442  and an annular OB area  1444  directly surrounding grass IB area  1442  and defined with grass or/and hard material. Grass can be natural or artificial. Area  1442  is defined inwardly by the inside edges of two opposite equal-width parallel straight end lines  1446 S and  1446 T (collectively “ 1446 ”) and the inside edges of two opposite equal-width parallel straight side lines  1448 U and  1448 V (collectively “ 1448 ”) extending between end lines  1446 . Each line  1446  or  1448  is an open boundary line. Lines  1446  and  1448 , usually approximately 10 cm wide, together form a rectangular closed boundary line  1446 / 1448  whose inside edge is a closed boundary for area  1442 . 
     Two goal lines  1450 S and  1450 T (collectively “ 1450 ”) extend between side lines  1448  parallel to end lines  1446  so that each goal line  1450  is 9.14 m (10 yd) away from nearest end line  1446 . Goal lines  1450  divide IB area  1442  into a playing field  1452  and two end zones  1454 S and  1454 T. Playing field  1452  extends between goal lines  1450 . End zone  1454 S or  1454 T extends between end line  1446 S or  1446 T and nearest goal line  1450 S or  1450 T. 
     Playing field  1452  has nineteen equal-width parallel straight yard lines  1456  extending between side lines  1448  parallel to goal lines  1450 . Consecutive ones of goal lines  1450  and yard lines  1456  are spaced 4.57 m (5 yd) apart. Yard line  1456  at the longitudinal middle of field  1452  is marked “ 50 ”. Alternate yard lines  1456  moving from center yard line  1456  toward each goal line  1450  are respectively marked “ 40 ”, “ 30 ”, “ 20 ”, and “ 10 ”. The football-playing structure has two pairs  1458 S and  1458 T of goal posts. A crossbar of each goal-post pair  1458 S or  1458 T is situated above, and spaced vertically apart from, part of end line  1446 S or  1446 T. Each crossbar is centered above its end line  1446  and is usually centrally supported by a curved support post mounted in OB area  1444 . Two upright bars extend vertically upward from the ends of each crossbar. Flexible vertical posts  1460 , commonly denominated pylons, are respectively situated at the intersections of side lines  1448  with lines  1446  and  1450 . 
     Football is actively played only in IB area  1442 . The players must be fully in area  1442  to actively participate in football. Special consequences such as penalties or play stoppages occur when the football or certain players, particularly a player in possession of the football, leave area  1442  during active play. In particular, a football player goes out of bounds during a football play when any part of the player&#39;s body or clothes, e.g., either of the player&#39;s shoes, contacts any of boundary lines  1446  and  1448 . Play is briefly suspended when any part of the body or clothes of the player in possession of the football contacts any of lines  1446  and  1448 . Similarly, a football goes out of bounds when it contacts any boundary line  1446  or  1448 , likewise resulting in a brief suspension of play. Hence, lines  1446  and  1448  are parts of OB area  1444 . The inside edge of each of lines  1446  and  1448  is its critical edge for determining whether object  104  embodied with a football or (any part of) a person including the person&#39;s shoes and other clothing is in or out of bounds. 
     A straight end-line path  1466 S or  1466 T defined with hard material is provided in the grass fully along each end line  1446 S or  1446 T such that it is fully situated in end-line path  1466 S or  1466 T. A straight side-line path  1468 U or  1468 V defined with hard material is provided in the grass fully along each side line  1448 U or  1448 V such that it is fully situated in side-line path  1468 U or  1468 V. End-line paths  1466 S and  1466 T (collectively “ 1466 ”) and side-line paths  1468 U and  1468 V (collectively “ 1468 ”) may be the bottoms of channels in grass if OB area  1444  is grass fully along IB area  1442 . If area  1444  is defined with hard material along boundary lines  1446  or  1448 , boundary-line (end-line and side-line) paths  1466  or  1468  merge into the hard material of area  1444 . 
     Each boundary-line path  1466  or  1468  preferably includes a narrow elongated straight part, termed an inside-edge path part, extending fully along the inside edge of that path&#39;s boundary line  1446  or  1448 . The inside-edge path part of each path  1466  or  1468  is usually no more than twice as wide as, preferably no wider than, its line  1446  or  1448 . If OB area  1444  is grass fully along the outside edges of lines  1446  or  1448 , each path  1466  or  1468  optionally includes a path part, termed an outside-edge path part, extending fully along the outside edge of that path&#39;s line  1446  or  1448 . Because football is actively played only in IB area  1442 , the presence of paths  1466  and  1468  along lines  1446  and  1448  generally has little effect on football play. 
     A narrow elongated straight part  1472 S or  1472 T of IB area  1442  lying fully along the inside edge of each end line  1446 S or  1446 T forms, as highest CC location priority for lines  1446 , a VC inside-edge ELA area part embodying a unit of SF zone  112 . A narrow elongated straight part  1474 U or  1474 V of area  1442  lying fully along the inside edge of each side line  1448 U or  1448 V forms, as highest CC location priority for lines  1448 , a VC inside-edge SLA area part embodying a unit of zone  112 . Each VC inside-edge LA part  1472 S,  1472 T,  1474 U, or  1474 V is located at the inside-edge path part of path  1466 S,  1466 T,  1468 U, or  1468 V so as to at least partly occupy that path part&#39;s width. Inside-edge LA parts  1472 S and  1472 T (collectively “ 1472 ”) and  1474 U and  1474 V (collectively “ 1474 ”) form a rectangular annular VC inside-edge BV LA area portion  1476 . The rectangular FC remainder  1478  of area  1442  bounded by LA area portion  1476  embodies a unit of FC SF zone  114 . 
     Each end line  1446 S or  1446 T is, as next highest CC location priority for lines  1446 , a VC end-line area part embodying a unit of SF zone  892  at end-line path  1466 S or  1466 T. Each side line  1448 U or  1448 V is, as next highest CC location priority for lines  1448 , a VC side-line area part embodying a unit of zone  892  at side-line path  1468 U or  1468 V. Boundary lines  1446  and  1448  form a rectangular annular VC boundary line area  1480 . OB area  1444  is an FC area part embodying a unit of SF zone  894 . 
     A narrow elongated straight part  1482 S or  1482 T of OB area  1444  lying fully along the outside edge of each end line  1446 S or  1446 T optionally forms a VC outside-edge ELA area part embodying a unit of SF zone  912 . A narrow elongated straight part  1484 U or  1484 V of area  1444  lying fully along the outside edge of each side line  1448 U or  1448 V optionally forms a VC outside-edge SLA area part embodying a unit of zone  912 . If area  1444  is grass fully along the outside edge of each boundary line  1446 S,  1446 T,  1448 U, or  1448 V, VC outside-edge LA part  1482 S,  1482 T,  1484 U, or  1484 V is located at the outside-edge path part of path  1466 S,  1466 T,  1468 U, or  1468 V so as to at least partly occupy that path part&#39;s width. Outside-edge LA parts  1482 S and  1482 T (collectively “ 1482 ”) and  1484 U and  1484 V (collectively “ 1484 ”) form a rectangular annular VC outside-edge BV LA area portion  1486 . For these options, the annular FC remainder  1488  of area  1444  bounded by LA area portion  1486  embodies a unit of SF zone  914 . 
     A VC structure part of IP structure  1440  extends to surface  102  at each of lines  1446  and  1448  and VC LA area parts  1472 ,  1474 ,  1482 , and  1484 . In particular, structure  1440  includes (a) VC inside-edge ELA structure consisting of two VC inside-edge ELA structure parts respectively formed with two units of VC region  106  and extending to surface  102  respectively at inside-edge ELA area parts  1472 , (b) VC inside-edge SLA structure consisting of two VC inside-edge SLA structure parts respectively formed with two units of region  106  and extending to surface  102  respectively at inside-edge SLA area parts  1474 , (c) VC end-line structure consisting of two VC end-line structure parts respectively formed with two units of VC region  886  and extending to surface  102  respectively at end lines  1446 , (d) VC side-line structure consisting of two VC side-line structure parts respectively formed with two units of region  886  and extending to zone  112  respectively at side lines  1448 , (e) VC outside-edge ELA structure consisting of two VC outside-edge ELA structure parts respectively formed with two units of VC region  906  and extending to surface  102  respectively at outside-edge ELA area parts  1482 , and (f) VC outside-edge SLA structure consisting of two VC outside-edge SLA structure parts respectively formed with two units of region  906  and extending to surface  102  respectively at outside-edge SLA area parts  1484 . 
     Each VC inside-edge ELA structure part normally appears along its ELA area part  1472 S or  1472 T as a PP BV color AIS or AIT embodying PP color A. Each VC inside-edge SLA structure part normally appears along its SLA area part  1474 U or  1474 V as a PP BV color AIU or AIV embodying color A. Each VC inside-edge ELA or SLA structure part is therefore a VC inside-edge BV LA structure part normally appearing along its LA area part  1472 S,  1472 T,  1474 U, or  1474 V as color AIS, AIT, AIU, or AIV. Each VC end-line structure part normally appears along its end line  1446 S or  1446 T as an AD BV color BBS or BBT embodying AD color B. Each VC side-line structure normally appears along its side line  1448 U or  1448 V as an AD BV color BBU or BBV embodying color B. Consequently, each VC end-line or side-line structure part is a VC BV line structure part normally appearing along its boundary line  1446 S,  1446 T,  1448 U, or  1448 V as color BBS, BBT, BBU, or BBV. Each VC outside-edge ELA structure part normally appears along its ELA area part  1482 S or  1482 T as an FR BV color COS or COT embodying FR color C. Each VC outside-edge SLA structure part normally appears along its SLA area part  1484 U or  1484 V as an FR BV color COU or COV embodying color C. Each VC outside-edge ELA or SLA structure part is thus a VC outside-edge BV LA structure part normally appearing along its LA area part  1482 S,  1482 T,  1484 U, or  1484 V as color COS, COT, COU, or COV. 
     IDVC portion  138  of each VC inside-edge BV LA structure part responds to object  104  impacting LA area part  1472 S,  1472 T,  1474 U, or  1474 V of that structure part at OC area  116  as described above for the general OI structure without intelligent control with changed color X embodied as a changed BV color XIS, XIT, XIU, or XIV materially different from PP BV color AIS, AIT, AIU, or AIV. IDVC portion  926  of each VC BV line structure part responds to object  104  impacting boundary line  1446 S,  1446 T,  1448 U, or  1448 V of that structure part at OC area  896  as prescribed for the general OI structure without intelligent control with altered color Y embodied as an altered BV color YBS, YBT, YBU, or YBV materially different from AD BV color BBS, BBT, BBU, or BBV. An FR IDVC portion of each VC outside-edge BV LA structure part responds to object  104  impacting LA area part  1482 S,  1482 T,  1484 U or  1484 V of that structure part at OC area  916  as prescribed for the general OI structure without intelligent control with modified color Z embodied as a modified BV color ZOS, ZOT, ZOU, or ZOV materially different from FR BV color COS, COT, COU, or COV. 
     IP structure  1440  preferably contains CC controller  1114  for implementing one of IP structures  1110  and  1170  or CC controller  1134  for implementing one of IP structure  1130  and  1200 . It is usually sufficient for controller  1114 / 1134  to operate as a duration controller for making OB determinations in IP structure  1440 . If controller  1114 / 1134  is to operate as an intelligent controller for making OB determinations, the inside-edge BV LA structure parts, their area parts  1472  and  1474 , the BV line structure parts, their lines  1446  and  1448 , the outside-edge BV LA structure parts, and their area parts  1482  and  1484  interact with controller  1114 / 1134  the same as the far-edge 3P LA structure parts, their area parts  1344 , the 3PL structure parts, their lines  1334 , the near-edge 3P LA structure parts, and their area parts  1358  respectively interact with controller  1114 / 1134  operating as an intelligent controller in basketball IP structure  1300  subject to the PP, AD, FR, and CP supplemental impact criteria being criteria for a football and/or a person&#39;s shoe, specifically a football shoe, impacting surface  102 . This includes using the location-dependent version of the CC capability to control the color changing in OB determinations. 
     As exemplified by  FIGS. 98-100  for basketball, volleyball, and football along with  FIGS. 96 and 97  for tennis, a general sports-playing IP structure employs the above-mentioned general sports-playing OI structure having surface  102  for being impacted by object  104  embodied as a sports instrument or a person, typically a player, including any clothing worn by the person. Surface  102  has (a) an IB area, exemplified by IB area  42 ,  1302 ,  1382 , or  1442 , defined by a closed boundary and (b) an OB area, exemplified by OB area  44 ,  1304 ,  1384 , or  1444 , surrounding the IB area and adjoining it along the closed boundary. A finite-width closed boundary line, exemplified by closed boundary line  28 / 46 ,  1306 / 1308 ,  1386 / 1388 , or  1446 / 1448 , extends fully along the closed boundary and has opposite inside and outside edges respectively nearest to and farthest from the center of the IB area. One of the line&#39;s inside and outside edges lies in one of the IB and OB areas. The other of the line&#39;s inside and outside edges meets the other of the IB and OB areas. 
     Let LA area parts  1242 E,  1244 E, and  1244 D along the inside edge of closed boundary line  28 / 46  in tennis IP structure  1230  be collectively termed inside-edge BV LA area portion  1242 E/ 1244 I. The closed boundary line is an object-related line of the general OI structure. The associated VC first-edge and second-edge structure parts for the boundary line are then respectively directly or inversely (a) VC inside-edge BV LA structure that extends to surface  102  at VC inside-edge BV LA area lying in the IB area, adjoining the inside edge of the line along at least part of the line&#39;s length, and exemplified by sometimes-discontinuous VC inside-edge BV LA area portion  1242 E/ 1244 I,  1342 ,  1428 , or  1476  and (b) VC outside-edge BV LA structure that extends to surface  102  at VC outside-edge BV LA area lying in the OB area, adjoining the outside edge of the line along at least part of the line&#39;s length, and exemplified by sometimes-discontinuous VC outside-edge BV LA area portion  1246 T,  1276 T,  1356 ,  1406 , or  1486 . 
     The outside-edge BV LA structure is the first-edge structure part and constitutes the highest CC location priority for the boundary line if it, including its inside edge, lies in the IB area. PP color A and changed color X of the first-edge structure part are then respectively a normal-state outside-edge BV LA color and a changed-state outside-edge BV LA color exemplified by the normal-state and changed-state colors of outside-edge LA area portion  1246 T,  1276 T, or  1406 . The inside-edge BV LA structure is the second-edge structure part for which its FR color C and modified color Z are respectively a normal-state inside-edge BV LA color and a changed-state inside-edge BV LA color exemplified by the normal-state and changed-state colors of inside-edge LA area portion  1242 E/ 1244 I or  1428 . 
     The inside-edge BV LA structure is the VC first-edge structure part and constitutes the highest CC location priority for the boundary line if it, including its outside edge, lies in the OB area. In that case, colors A and X of the first-edge structure part are respectively a normal-state inside-edge BV LA color and a changed-state inside-edge BV LA color exemplified by the normal-state and changed-state colors of inside-edge LA area portion  1342  or  1476 . The outside-edge BV LA structure is the VC second-edge structure part for which its colors C and color Z are respectively a normal-state outside-edge BV LA color and a changed-state outside-edge BV LA color exemplified by the normal-state and changed-state colors of outside-edge LA area portion  1356  or  1486 . 
     In either case, the VC line structure of the general OI structure constitutes, as the next highest CC location priority for the boundary line, VC boundary-line structure extending to surface  102  at the line along at least part of its length. AD color B and altered color Y of the line structure are respectively a normal-state BV line color and a changed-state BV line color exemplified by the normal-state and changed-state line color(s) of the VC area of closed boundary line  28 / 46 ,  1306 / 1308 ,  1386 / 1388 , or  1446 / 1448 . 
     An internal line different from the closed boundary line and exemplified by any of servicelines  34 , 3P lines  1334 , and attack lines  1396  is another object-related line of the general OI structure. The general sports-playing IP structure sometimes has one or more score-achieving structures, exemplified by baskets  1316 S and  1316 T, situated on or near surface  102 . If so, one or more of the object-related internal lines, exemplified by internal 3P lines  1334 , may be pertinent to scoring accomplished with the one or more score-achieving structures. A selected one of the edges of each object-related internal line is its critical edge for determining how impact of object  104  on or near that line affects play. The selected edge of each internal line is, for convenience, arbitrarily deemed to be its first edge. 
     The VC first-edge structure part for each such internal line is, as its highest CC location priority, VC first-edge internal LA structure extending to surface  102  at VC first-edge internal LA area adjoining the first edge of that line and exemplified by each VC internal LA area part/portion  1242 S,  1272 ,  1344 , or  1408 . Colors A and X of the first-edge structure part are then respectively a normal-state first-edge internal LA color and a changed-state first-edge internal LA color exemplified by the normal-state and changed-state colors of each part/portion  1242 S,  1272 ,  1344 , or  1408 . 
     The VC line structure part for each such internal line is, as its next highest CC location priority, VC internal-line structure extending to surface  102  at that line along at least part of the line&#39;s length. Colors B and Y of the line structure are respectively a normal-state internal-line color and a changed-state internal-line color exemplified by the normal-state line and changed-state colors of the VC area of each internal line  34 ,  1334 , or  1396 . 
     The VC second-edge structure part for each such internal line is VC second-edge internal LA structure extending to surface  102  at VC second-edge internal LA area adjoining the second edge of that line and exemplified by each VC internal LA area part  1240 S,  1358 , or  1430 . Color C and Z of the second-edge structure part are then respectively a normal-state second-edge internal LA color and a changed-state second-edge internal LA color exemplified by the normal-state and changed-state colors of each part  1240 S,  1358 , or  1430 . 
       FIG. 101  illustrates an IP structure  1500  containing OI structure  900  or, preferably, cell-containing OI structure  1100 , incorporated into a baseball or softball field to form a ball-playing structure that provides assistance in making decisions on where a batted baseball or softball impacts certain parts of the field. Surface  102  includes an IB ground area  1502 , termed fair area, having a perimeter shaped roughly like a quarter circle, and an OB ground area  1504 , termed foul area, that adjoins fair area  1502  along left and right foul lines  1506 L and  1506 R (collectively “ 1506 ”). Fair territory and foul territory respectively go vertically upward from areas  1502  and  1504 . Foul lines  1506 , typically 5-8 cm wide, are parts of fair territory and have straight fair-area portions extending perpendicular to each other in fair area  1502  so as to essentially meet each other. Each foul line  1506  has an outside (or foul-area) edge meeting foul area  1504  and an inside (or fair-area) edge lying in fair area  1502 . 
     A batted baseball or softball embodying object  104  for IP structure  1500  is termed batted ball  104 , sometimes simply ball  104 . Batted ball  104  is fair, in bounds, whenever it impacts anywhere in fair territory including either foul line  1506 . Ball  104  simultaneously impacting a foul line  1506  and a tangible part of foul territory is fair. Ball  104  solely impacting a tangible part of foul territory is foul, out of bounds. The outside edge of each foul line  1506  is thus its critical edge for determining whether ball  104  is fair or foul. 
     Fair area  1502  further includes a home plate  1508  constituting the meeting location of foul lines  1506 , a first base  1510  along right foul line  1506 R, a second base  1512  between foul lines  1506  generally opposite home plate  1508 , and a third base  1514  along left foul line  1506 L. Plate  1508  and bases  1510 ,  1512 , and  1514  lie at the corners of an imaginary square. Area  1502  is divided into general infield and outfield areas  1516  and  1518 . General infield area  1516  consists of a grass area  1520  and a dirt area  1522  which surrounds grass infield area  1520  and in which bases  1510 ,  1512 , and  1514  are located. Grass can again be natural or artificial. Grass infield area  1520  surrounds a dirt pitcher&#39;s mound  1524  whose central point lies at the centroid of plate  1508  and bases  1510 ,  1512 , and  1514 . Dirt infield area  1522  extends along parts of foul lines  1506  to plate  1508 . 
     Dirt infield area  1522  adjoins a foul-territory dirt area  1526  lying in foul area  1504 . “FLT” hereafter means foul-territory. FLT dirt area  1526  extends along foul lines  1506  respectively beyond bases  1514  and  1510 . In particular, dirt area  1526  includes (i) a left FLT dirt area section  1526 L extending from home plate  1508  along the outside edge of left foul line  1506 L beyond third base  1514  and (ii) a right FLT dirt area section  1526 R extending from plate  1508  along the outside edge of right foul line  1506 R beyond first base  1510 . Batters&#39; boxes  1528 L and  1528 R are situated respectively to the left and right of plate  1508  partly in infield area  1522  and partly in FLT dirt area  1526 . A baseball or softball is batted ball  104  when a player, the batter, standing in either of batters&#39; boxes  1528 L and  1528 R hits the ball with a bat after a player, the pitcher, standing on pitcher&#39;s mound  1524  throws the ball toward plate  1508 . A catcher&#39;s box  1530  lies in area  1526  behind plate  1508 . 
     General outfield area  1518  extends to an upward-extending outfield barrier  1532  commonly termed a “fence” but often including one or more walls. Outfield barrier  1532  has an inside barrier area  1534  facing fair area  1502  so as to meet it and foul area  1504 . The fair-area portions of foul lines  1506  substantially meet barrier  1532 . Foul lines  1506  have substantially-straight barrier portions extending up inside barrier area  1534 . The longitudinal centerlines of lines  1506  lie respectively in perpendicularly intersecting vertical planes. Barrier area  1534  constitutes part of surface  102  so that it is non-flat here. 
     Letting “FRT” hereafter mean fair-territory, barrier area  1534  consists of (i) a central FRT inside barrier area section  1534 C which meets fair area  1502 , (ii) a left FLT inside barrier area section  1534 L which meets foul area  1504  and is continuous with FRT inside barrier area section  1534 C along left foul line  1506 L, and (iii) a right FLT inside barrier area section  1534 R which meets area  1504  and is continuous with FRT barrier section  1534 C along right foul line  1506 R. Barrier  1532 , specifically the bottom edge of FRT barrier section  1534 C, and lines  1506 , specifically their lateral portions, inwardly define fair area  1502 . 
     A grass area  1536  of outfield area  1518  adjoins dirt infield area  1522 . Although grass outfield area  1536  sometimes extends to barrier  1532 , a warning track  1538  defined with dirt or other hard material is often situated between barrier  1532  and outfield area  1536 . Warning track  1538  has a warning track area consisting of (i) a central FRT track area section  1540 C extending along barrier  1532  between foul lines  1506 , (ii) a left FLT track area section  1540 L lying in foul area  1504  along left foul line  1506 L, and (iii) a right FLT track area section  1540 R lying in area  1504  along right foul line  1506 R. Item  1542  indicates an FLT grass area lying in foul area  1504 , adjoining grass outfield area  1536 , and adjoining FLT dirt area  1526  so as to be spaced apart from batters&#39; boxes  1528 L and  1528 R and catcher&#39;s box  1530 . FLT grass area  1542  includes (i) a left FLT grass area section  1542 L lying along left FLT dirt area section  1526 L and the outside edge of left foul line  1506 L beyond dirt section  1526 L and (ii) a right FLT grass area section  1542 R lying along right FLT dirt area section  1526 R and the outside edge of right foul line  1506 R beyond dirt section  1526 R. Although not indicated in  FIG. 101 , FLT track area sections  1540 L and  1540 R often extend continuously along FLT grass area  1542  to form a composite FLT track area. 
     A straight channel  1544 L or  1544 R extending down to hard material is provided in the grass along foul line  1506 L or  1506 R from infield area  1516 , specifically dirt area  1522 , either to barrier  1532  or, if present, to track  1538 . The part  15060 L or  15060 R, termed a main outfield foul-line area part, of each foul line  1506 L or  1506 R extending from dirt infield area  1522  through grass outfield area  1536  either to barrier  1532  or, if present, to track  1538  lies in foul-line channel  1544 L or  1544 R along its hard material. Foul-line channel  1544 L or  1544 R is usually wider than main outfield foul-line area part  15060 L or  15060 R so as to include two elongated straight portions respectively lying in areas  1502  and  1504  and extending fully along both edges of outfield foul-line part  15060 L or  15060 R. Channels  1544 L and  1544 R (collectively “ 1544 ”) can, for example, be 0.5-1 m wide. 
     In addition to outfield foul-line part  15060 L or  15060 R, each foul line  1506 L or  1506 R includes (a) an infield-path (or base-path) foul-line area part  1506 PL or  1506 PR extending essentially from home plate  1508  to base  1514  or  1510 , (b) a beyond-path (“BP”) infield foul-line area part  15061 L or  15061 R extending from base  1514  or  1510  along dirt infield area  1522  to grass outfield area  1536 , (c) a track foul-line area part  1506 TL or  1506 TR extending from outfield area  1536  along track  1538  substantially to barrier  1532  if track  1538  is present, and (d) a barrier foul-line area part  1506 BL or  1506 BR extending substantially from the bottom of barrier  1532  up central FRT inside barrier area section  1534 C substantially to the top of barrier  1532 . If track  1538  is absent, outfield foul-line part  15060 L or  15060 R extends from infield area  1522  through outfield area  1536  to barrier  1532 . 
     Left and right foul poles  1546 L and  1546 R are situated closely behind barrier  1532  and extend vertically upward beyond barrier  1532 . The longitudinal centerlines of foul poles  1546 L and  1546 R, both straight, respectively lie largely in the intersecting vertical planes of the longitudinal centerlines of foul lines  1506 L and  1506 R. Left-pole and right-pole screens  1548 L and  1548 R respectively often extend along the FRT sides of foul poles  1546 L and  1546 R. Foul poles  1546 L and  1546 R are deemed to be respective extensions of foul lines  1506 L and  1506 R and parts of fair territory. Batted ball  104  is fair, a home run, if it impacts either foul pole  1546 L or  1546 R, including screen  1548 L or  1548 R. 
     A narrow elongated straight part  1550 L or  1550 R of each FLT dirt area section  1526 L or  1526 R lying fully along the outside, i.e., FLT, edge of BP infield foul-line part  15061 L or  15061 R forms, as highest CC location priority for BP infield foul-line line parts  15061 L and  15061 R (collectively “ 15061 ”), a VC BP infield-adjoining FLT LA part embodying a unit of SF zone  112 . A narrow elongated straight part  1552 L or  1552 R of FLT grass area section  1542 L or  1542 R lying fully along the outside, or FLT, edge of outfield foul-line part  15060 L or  15060 R forms, as highest CC location priority for outfield foul-line line parts  15060 L and  15060 R (collectively “ 15060 ”), a VC main outfield-adjoining FLT LA area part lying in foul-line channel  1544 L or  1544 R along its hard material and embodying a unit of zone  112 . If track  1538  is present, a narrow elongated straight part  1554 L or  1554 R of FLT track area section  1540 L or  1540 R lying fully along the outside, or FLT, edge of track foul-line part  1506 TL or  1506 TR forms, as highest CC location priority for track foul-line parts  1506 TL and  1506 TR (collectively “ 1506 T”), a VC track FLT LA area part embodying a unit of zone  112 . A narrow elongated straight part  1556 L or  1556 R of FLT barrier area section  1534 L or  1534 R lying fully along the outside, or FLT, edge of barrier foul-line part  1506 BL or  1506 BR forms, as highest CC priority for barrier foul-line line parts  1506 BL and  1506 BR (collectively “ 1506 B”), a VC barrier FLT LA area part embodying a unit of zone  112 . VC FLT LA parts  1550 L,  1552 L, and  1556 L or  1550 R,  1552 R, and  1556 R and, if present, VC track FLT LA part  1554 L or  1554 R are usually continuous with one another to form a VC BP joint FLT LA area portion  1558 L or  1558 R extending from base  1514  or  1510  to barrier area section  1534 L or  1534 R and then vertically up it. There may be a small gap between barrier FLT LA part  1556 L or  1556 R and the remainder of BP joint FLT LA area portion  1558 L or  1558 R at the bottom of barrier  1532 . 
     Each foul-line part  15061 ,  15060 , or  1506 B constitutes, as next highest CC location priorities for foul-line parts  15061 ,  15060 , or  1506 B, a VC foul-line area part embodying a unit of SF zone  892 . If track  1538  is present, each track foul-line part  1506 T is, as next highest CC location priority for track foul-line line parts  1506 T, a VC foul-line area part embodying a unit of zone  892 . VC foul-line parts  15061 L,  15060 L, and  1506 BL or  15061 R,  15060 R, and  1506 BR and, if present, VC track foul-line part  1506 TL or  1506 TR are usually continuous with one another to form a VC BP joint foul-line area portion  1506 JL or  1506 JR extending from base  1514  or  1510  to barrier  1532  and then vertically up FRT barrier area section  1534 C. There may be a small gap between barrier foul-line part  1506 BL or  1506 BR and the remainder of BP joint foul-line area portion  1506 JL or  1506 JR at the bottom of barrier  1532 . 
     Each of (a) the FC remainder  1560 L or  1560 R of FLT dirt area section  1526 L or  1526 R, (b) the FC remainder  1562 L or  1562 R of FLT grass area section  1542 L or  1542 R, (c) the FC remainder  1564 L or  1564 R of FLT track area section  1540 L or  1540 R if track  1538  is present, and (d) the FC remainder  1566 L or  1566 R of FLT barrier area section  1534 L or  1534 R embodies a unit of SF zone  114 . Each of (a) the FC remainder  1570  of dirt infield area  1522 , i.e., the part outside foul-line parts  15061 , (b) the FC remainder  1572  of grass outfield area  1536 , i.e., the part outside foul-line parts  15060 , (c) the FC remainder  1574  of FRT track area section  1540 C, i.e., the part outside foul-line parts  1506 T, if track  1538  is present and (d) the FC remainder  1576  of FRT barrier area section  1534 C, i.e., the part outside foul-line parts  1506 B, embodies a unit of SF zone  894 . 
     A narrow elongated straight part  1580 L or  1580 R of dirt infield area  1522  lying fully along the inside, i.e., FRT, edge of each BP infield foul-line part  15061 L or  15061 R optionally forms a VC BP infield FRT LA area part embodying a unit of SF zone  912 . If foul-line channels  1544  are provided along foul lines  1506 , a narrow elongated straight part  1582 L or  1582 R of grass outfield area  1536  lying fully along the inside, or FRT, edge of each outfield foul-line part  15060 L or  15060 R optionally forms a VC main outfield FRT LA area part lying in channel  1544 L or  1544 R and embodying a unit of zone  912 . If track  1538  is present, a narrow elongated straight part  1584 L or  1584 R of FRT track area section  1540 C lying fully along the inside, or FRT, edge of each track foul-line part  1506 TL or  1506 TR optionally forms a VC track FRT LA area part embodying a unit of zone  912 . A narrow elongated straight part  1586 L or  1586 R of FRT inside barrier area section  1534 C lying fully along the inside, or FRT, edge of each barrier foul-line part  1506 BL or  1506 BR optionally forms a VC barrier FRT LA area part embodying a unit of zone  912 . VC FRT LA parts  1580 L,  1582 L, and  1586 L or  1580 R,  1582 R, and  1586 R and (if present) VC track FRT LA part  1584 L or  1584 R are usually continuous with one another to form a VC BP joint FRT LA area portion  1588 L or  1588 R extending from base  1514  or  1510  to barrier  1532  and then vertically up barrier area section  1534 C. There may be a small gap between barrier LA part  1586 L or  1586 R and the remainder of BP joint FRT LA area portion  1588 L or  1588 R at the bottom of barrier  1532 . 
     Each of (a) the FC part  1590  of dirt infield area  1522  outside foul-line parts  15061  and LA parts  1580 L and  1580 R, (b) the FC part  1592  of grass outfield area  1536  outside foul-line parts  15060  and LA parts  1582 L and  1582 R, (c) the FC part  1594  of FRT track area section  1540 C outside foul-line parts  1506 T and LA parts  1584 L and  1584 R if track  1538  is present, and (d) the FC part  1596  of barrier FRT area section  1534 C outside foul-line parts  1506 B and LA parts  1586 L and  1586 R embodies a unit of SF zone  914  in the preceding options. 
     A VC structure portion of IP structure  1500  extends to surface  102  at each of VC BP joint foul-line area portions  1506 JL and  1506 JR (collectively “ 1506 J”) and VC BP joint LA area portions  1558 L and  1558 R (collectively “ 1558 ”) and  1588 L and  1588 R (collectively “ 1588 ”). Structure  1500  specifically includes (i) VC BP joint FLT LA structure consisting of two VC BP joint FLT LA structure portions extending to surface  102  respectively at joint FLT LA area portions  1558 , (ii) VC BP joint foul-line structure consisting of two VC BP joint foul-line structure portions extending to surface  102  respectively at joint foul-line area portions  1506 J, and (iii) VC BP joint FRT LA structure consisting of two VC BP joint FRT LA structure portions extending to surface  102  respectively at joint FRT LA area portions  1588 . 
     Each VC BP joint FLT LA structure portion consists of (a) a VC BP infield-adjoining FLT LA structure part formed with a unit of VC region  106  and extending to surface  102  at infield-adjoining FLT LA area part  1550 L or  1550 R, (b) a VC main outfield-adjoining FLT LA structure part formed with a unit of region  106  and extending to surface  102  at main outfield-adjoining FLT LA area part  1552 L or  1552 R, (c) a VC track FLT LA structure part formed with a unit of region  106  and extending to surface  102  at track FLT LA area part  1554 L or  1554 R if track  1538  is present, and (d) a VC barrier FLT LA structure part formed with a unit of region  106  and extending to surface  102  at barrier FLT LA area part  1556 L or  1556 R. Each VC joint foul-line structure portion consists of (a) a VC BP infield foul-line structure part formed with a unit of VC region  886  and extending to surface  102  at BP infield foul-line area part  15061 L or  15061 R, (b) a VC main outfield foul-line structure part formed with a unit of region  886  and extending to surface  102  at main outfield foul-line area part  15060 L or  15060 R, (c) a VC track foul-line structure part formed with a unit of region  886  and extending to surface  102  at track foul-line area part  1506 TL or  1506 TR if track  1538  is present, and (d) a VC barrier foul-line structure part formed with a unit of region  886  and extending to surface  102  at barrier foul-line area part  1506 BL or  1506 BR. Each VC joint FRT LA structure consists of (a) a VC BP infield FRT LA structure part formed with a unit of VC region  906  and extending to surface  102  at infield FRT LA area part  1580 L or  1580 R, (b) a VC main outfield FRT LA structure part formed with a unit of region  906  and extending to surface  102  at main outfield FRT LA area part  1582 L or  1582 R, (c) a VC track FRT LA structure part formed with a unit of region  906  and extending to surface  102  at track FRT LA area part  1584 L or  1584 R if track  1538  is present, and (d) a VC barrier FRT LA structure part formed with a unit of region  906  and extending to surface  102  at barrier FRT LA area part  1586 L or  1586 R. 
     Batted ball  104  is fair if it impacts a joint foul-line portion  1506 J or/and a joint FRT LA portion  1588 . Ball  104  is also fair if it simultaneously impacts a joint foul-line portion  1506 J and adjoining joint FLT LA portion  1558 . However, ball  104  solely impacting an FLT LA portion  1558  or simultaneously impacting an FLT LA portion  1558  and one or more of an FC FLT dirt part  1560 L or  1560 R, FC FLT grass part  1562 L or  1562 R, FC FLT track part  1564 L or  1564 R if track  1538  is present, and FC FLT barrier part  1566 L or  1566 R without further simultaneously impacting anywhere in fair area  1502  or FRT barrier section  1534 C is foul. 
     Letting “FLV” mean foul-line vicinity, each VC BP infield-adjoining FLT LA structure part normally appears along its LA area part  1550 L or  1550 R as a PP infield-vicinity FLV color AIL or AIR. Each VC main outfield-adjoining FLT LA structure part normally appears along its LA area part  1552 L or  1552 R as a PP outfield FLV color AOL or AOR. If track  1538  is present, each VC track FLT LA structure part normally appears along its LA area part  1554 L or  1554 R as a PP track FLV color ATL or ATR. Each VC barrier FLT LA structure part normally appears along its LA area part  1556 L or  1556 R as a PP barrier FLV color ABL or ABR. Normal-state colors AIL, AIR, AOL, AOR, ATL, ATR, ABL, and ABR, each embodying PP color A, are usually the same. 
     Each VC BP infield foul-line structure part normally appears along its foul-line area part  15061 L or  15061 R as an AD infield-vicinity FLV color BIL or BIR. Each VC main outfield foul-line structure part normally appears along its foul-line area part  15060 L or  1506 OR as an AD outfield FLV color BOL or BOR. If track  1538  is present, each VC track foul-line structure part normally appears along its foul-line area part  1506 TL or  1506 TR as an AD track FLV color BTL or BTR. Each VC barrier foul-line structure part normally appears along its foul-line area part  1506 BL or  1506 BR as an AD barrier FLV color BBL or BBR. Infield-path foul-line area parts  1506 PL and  1506 PR are FC line area parts that appear as the same fixed color FL. Normal-state colors BIL, BIR, BOL, BOR, BTL, BTR, BBL, and BBR, each embodying AD color B, are usually largely color FL. 
     Each VC BP infield FRT LA structure part normally appears along its LA area part  1580 L or  1580 R as an FR infield-vicinity FLV color CIL or CIR. Each VC main outfield FRT LA structure part normally appears along its LA area part  1582 L or  1582 R as an FR outfield FLV color COL or COR. If track  1538  is present, each VC track FRT LA structure part normally appears along its LA area part  1584 L or  1584 R as an FR track FLV color CTL or CTR. Each VC barrier FRT LA structure part normally appears along its LA area part  1586 L or  1586 R as an FR barrier FLV color CBL or CBR. Normal-state colors CIL, CIR, COL, COR, CTL, CTR, CBL, and CBR, each embodying FR color C, are usually the same. 
     IDVC portion  138  of each VC FLT LA structure part responds to ball  104  impacting LA area part  1550 L,  1550 R,  1552 L,  1552 R,  1554 L,  1554 R,  1556 L, or  1556 R of that structure part at OC area  116  as described above for the general OI structure without intelligent control with changed color X embodied as a changed FLV color XIL, XIR, XOL, XOR, XTL, XTR, XBL, or XBR materially different from PP FLV color AIL, AIR, AOL, AOR, ATL, ATR, ABL, orABR of that structure part. Each color XIL or XIR is a changed infield-vicinity FLV color. Each color XOL or XOR is a changed outfield FLV color. Each color XTL or XTR is a changed track FLV color. Each color XBL or XBR is a changed barrier FLV color. Changed-state colors XIL, XIR, XOL, XOR, XTL, XTR, XBL, and XBR, each embodying changed color X, are usually the same. 
     IDVC portion  926  of each VC foul-line structure part responds to ball  104  impacting foul-line area part  15061 L,  15061 R,  1506 OL,  1506 OR,  1506 TL,  1506 TR,  1506 BL, or  1506 BR of that structure part at OC area  896  as prescribed for the general OI structure without intelligent control with altered color Y embodied as an altered FLV color YIL, YIR, YOL, YOR, YTL, YTR, YBL, or YBR materially different from AD FLV color BIL, BIR, BOL, BOR, BTL, BTR, BBL, or BBR. Each color YIL or YIR is an altered infield-vicinity FLV color. Each color YOL or YOR is an altered outfield FLV color. Each color YTL or YTR is an altered track FLV color. Each color YBL or YBR is an altered barrier FLV color. Changed-state colors YIL, YIR, YOL, YOR, YTL, YTR, YBL, and YBR, each embodying altered color Y, are usually the same. 
     An FR IDVC portion of each VC FRT LA structure part responds to ball  104  impacting LA area part  1580 L,  1580 R,  1582 L,  1582 R,  1584 L,  1584 R,  1586 L, or  1586 R of that structure part at an OC area  916  as prescribed for the general OI structure without intelligent control with modified color Z embodied as a modified FLV color ZIL, ZIR, ZOL, ZOR, ZTL, ZTR, ZBL, or ZBR materially different from FR FLV color CIL, CIR, COL, COR, CTL, CTR, CBL, or CBR. Each color ZIL or ZIR is a modified infield-vicinity FLV color. Each color ZOL or ZOR is a modified outfield FLV color. Each color ZTL or ZTR is a modified track FLV color. Each color ZBL or ZBR is a modified barrier FLV color. Changed-state colors ZIL, ZIR, ZOL, ZOR, ZTL, ZTR, ZBL, and ZBR, each embodying modified color Z, are usually the same. 
     IP structure  1500  preferably contains CC controller  1114  for implementing one of IP structures  1110  and  1170  or CC controller  1134  for implementing one of IP structure  1130  and  1200 . It is usually sufficient for controller  1114 / 1134  to operate as a duration controller for making fair/foul determinations. If controller  1114 / 1134  is to operate as an intelligent controller for making fair/foul determinations, the BP infield-adjoining FLT LA structure parts, their area parts  1550 L and  1550 R, the VC BP infield foul-line structure parts, their area parts  15061 , the BP infield FRT LA structure parts, and their area parts  1580 L and  1580 R interact with controller  1114 / 1134  the same as the VC far-edge 3P LA structure parts, their area parts  1344 , the 3PL structure parts, their lines  1334 , the near-edge 3P LA structure parts, and their area parts  1358  respectively interact with controller  1114 / 1134  operating as an intelligent controller in basketball IP structure  1300  subject to the PP, AD, FR, and CP supplemental impact criteria being criteria for a baseball/softball impacting surface  102 . The same applies to (a) the main outfield-adjoining FLT LA structure parts, their area parts  1552 L and  1552 R, the main outfield foul-line structure parts, their area parts  15060 , the main outfield FRT LA structure parts, and their area parts  1582 L and  1582 R, (b) the track FLT LA structure parts, their area parts  1554 L and  1554 R, the track foul-line structure parts, their area parts  1506 T, the track FRT LA structure parts, and their area parts  1584 L and  1584 R if track  1538  is present, and (c) the barrier FLT LA structure parts, their area parts  1556 L and  1556 R, the barrier foul-line structure parts, their area parts  1506 B, the barrier FRT LA structure parts, and their area parts  1586 L and  1586 R. 
     Depending on the configuration of the ballpark especially for professional baseball, the CC capability can be utilized near the top of selected area of barrier  1532  to determine whether batted ball  104  impacting that area is, or is not, a home run. 
     A basketball, volleyball, football, or baseball/softball IP structure according to the invention may have less CC capability than what occurs in IP structure  1300 ,  1380 ,  1440 , or  1500 . In general, a basketball, volleyball, football, or baseball/softball IP structure according to the invention selectively contains one or more of the VC structures parts or portions described above for structure  1300 ,  1380 ,  1440 , or  1500  generally provided that the basketball, volleyball, football, or baseball/softball IP structure usually contains both of each pair of symmetrically situated VC structure parts or portions. When the CC capability is provided at elongated area directly along the non-critical edge of a line, the elongated area along the critical edge of the line is usually at least as wide as, preferably wider than, the elongated area along the non-critical edge of the line. The width of the elongated area along the critical edge usually exceeds the width of the elongated area along the non-critical edge by approximately the width of that line. 
     The present CC capability can be used in numerous other sports, especially where a penalty is assessed or a reward is made or/and active play is temporarily stopped if an object, such as a ball, impacts certain areas. Other sports suitable for the CC capability include squash, racketball, racquetball, handball (American), team handball (European), jai alai, platform tennis, paddle tennis, Basque pelota, padel, paleta fronton, real tennis, soft tennis, and squash tennis. In each of these other sports, each location having the CC capability contains at least one unit of VC region  106 , typically at or directly along a finite-width line where a penalty/reward/play-stoppage decision needs to be made. SF zone  112  of each unit of region  106  can be the line or an area, usually elongated, extending along the line so as to adjoin it on one edge (or side) or the other depending on the rules of the sport. 
     Preferably, the CC capability is embodied with units of both VC regions  106  and  886  similar to what occurs in tennis IP structure  1260 . One of SF zones  112  and  892  is then embodied with the line. The other of zones  112  and  892  is embodied with an area, again usually elongated, extending directly along the line so as to adjoin it on one edge or the other depending on the sport&#39;s rules. The CC capability can be embodied with units of VC regions  106 ,  886 , and  906  similar to what occurs in tennis IP structure  1230 . If so, zone  892  is embodied with the line. Zones  112  and  892  are then respectively embodied with a pair of areas, likewise usually elongated, adjoining the line along both edges. 
     Each unit of VC region  106  preferably includes components  182  and  184  typically implemented as in OI structure  200 . Each unit of VC region  886  preferably includes components  932  and  934  typically implemented as in OI structure  930 . Each unit of VC region  906  preferably includes an IS component and a CC component typically implemented the same as CC component  184  in structure  200 . 
     Squash played inside a hollow rectangular court similar to a shoe box but potentially open at the top has a floor, a front wall, two parallel sidewalls, a back wall, and usually a ceiling. The top surface of the floor, the inside surfaces of the walls, and the bottom surface of the ceiling (when present) embody surface  102 . A squash court employs lines on the insides of the walls and the top of the floor. An out line is formed by a straight front-wall line extending parallel to the floor, a straight back-wall line extending parallel to the floor at a lower height above the floor than the front-wall line, and two straight side-wall lines extended slantedly from the front-wall line to the back-wall line. The front wall has a straight service line extending parallel to the floor. A rectangular metal plate, usually substantially tin, extends from the floor partway up the front wall and ends below the service line. Lines on the floor include a short line extending parallel to the front (or back) wall and a half-court line extending perpendicular to the short line. The short and half-court lines in conjunction with the side and back walls define inwardly two quarter courts. Each quarter court has a service box spaced apart from the half-court line and extending to the closest sidewall. 
     A served ball embodying object  104  in squash is served with the server&#39;s feet/shoes positioned in the service box of one of the quarter courts. The ball must impact the front wall above the top edge of the service line and below the bottom edge of the front-wall line, i.e., the part of the out line on the front wall, and then impact the floor fully in the other (or opposite) quarter court, i.e., beyond the outside edge of the short line, where “outside” is again relative to the front wall, and inside the inside edge of the half-court line, where “inside” is relative to that other quarter court, in order to be “in”. A returned ball embodying object  104  must impact the front wall above the tin plate and, in impacting the front wall or any other wall, must impact each wall below the out line in order to be “in”. 
     The top edge of the service line, the bottom edge of the out line, and the outside edge of the short line constitute the critical edges of those lines. Hence, the CC capability is preferably at least provided as three units of SF zone  112  respectively in three elongated areas, usually straight, directly along the top edge of the service line, the bottom edge of the out line, and the outside edge of the short line. The server can be positioned in the service box of either quarter court depending on the play status so that each edge of the half-court line constitutes its critical edge at some point. The CC capability is then preferably at least provided as units of SF zones  112  and  912  in elongated areas, usually straight, directly along both edges of the half-court line. The CC capability can also be provided as a unit of SF zone  892  at each service, out, short, or half-court line. 
     The top of the tin plate forms a straight zero-width line extending parallel to the floor and essentially having a critical edge along the front wall. Inasmuch as a returned ball impacting the tin plate is “out”, the CC capability is preferably at least provided as a unit of SF zone  112  in elongated front-wall area, usually straight, directly along, and extending upward from, the top edge of the tin plate. The CC capability can also be provided as a unit of SF zone  892  in an elongated cover plate, usually largely rectangular, situated over the tin plate directly along, and extending downward from, its top edge partway to the floor. Alternatively, the tin plate can be replaced with CC capability provided as a unit of zone  892  in elongated front-wall area, usually largely straight, extending downward from the prior location of the top of the tin plate partway to the floor. A narrower tin plate can extend from that unit of zone  892  in the elongated front-wall area down to the floor. 
     Racketball uses the same court as squash. The ball in/out rules during service and return play in racketball are the same as in squash except that racketball apparently does not use the parts of the out line along the side and back walls. The locations provided with CC capability for squash are adequate for racketball. 
     Racquetball, different from racketball, is played inside a rectangular court similar to a shoebox having a floor, a front wall, two sidewalls, a back wall, and a ceiling. Handball (American) is played both indoors in a rectangular court having a floor, a front wall, two sidewalls, a back wall, and a ceiling and outdoors in a rectangular court having a floor, a front wall, and two parallel sidewalls but no back wall or ceiling. In both racquetball and handball, the top surface of the floor, the adjoining surfaces of the walls, and the bottom surface of the ceiling (when present) embody surface  102 . 
     Both racquetball and handball employ a short line located on the top of the floor and extending parallel to the front wall. A served ball embodying object  104  must impact surface  102  beyond (or behind) the outside (or back) edge of the straight short line for the ball to be “in” where “outside” (or “back”) is relative to the front wall. When the back wall is absent, handball employs a straight long line located on the top of the floor beyond the short line and extending parallel to the front wall. A served or returned ball embodying object  104  is “in” if it impacts the long line but “out” if it impacts surface  102  beyond the outside edge of the long line. The outside edge of the short line or, for handball, the long line is its critical edge. The CC capability is preferably at least provided as a unit of SF zone  112  in elongated area, usually largely straight, lying directly along the outside edge of each short or long line. The CC capability can also be provided as a unit of SF zone  892  at each short or long line. 
     Handball is also played in a one-wall version in which the top of the floor has two parallel sidelines extending perpendicular to the short and long lines. A served or returned ball embodying object  104  is “in” if it impacts either side line but “out” if it impacts surface  102  beyond the outside edge of either side line. The outside edge of each side line is its critical edge. 
     Team handball (European) is played between two teams on a court whose top surface embodies surface  102  and consists of a rectangular IB area divided into two half courts and an OB area directly surrounding the IB area. Each half court has a number of lines, including a long curved goal-area line (6-m line) and a short straight goalkeeper&#39;s restraining line (4-m line). Neither foot, specifically shoe, of either goalkeeper is permitted to impact surface  102  outside that goalkeeper&#39;s restraining line during a 7-m free-throw attempt before the ball has left the hand(s) of the shooter. The critical edge of each goalkeeper&#39;s restraining line is its outside edge, i.e., the edge farthest from the nearest goal line, for object  104  embodied with a shoe such as that of either goalkeeper. Either edge of each goal area line can variously act as its critical edge for object  104  similarly embodied with a shoe of a player. 
     The CC capability is provided for the goal-area lines and/or the goalkeeper restraining lines in an IP structure formed with two team handball goal fixtures and a team handball court configured to implement OI structure  900  or  1100  (a) using CC controller  1114  or  1134  for implementing IP structure  1110  or  1130  or/and (b) IG system  1152  or  1182  implementing IP structure  1170  or  1200  when controller  1114  or  1134  and system  1152  or  1182  are both present. Controller  1114 / 1134  in the team handball IP structure operates as an intelligent controller for the goalkeeper&#39;s restraining lines and the goal area lines. In particular, controller  1114 / 1134  usually causes color change at elongated area, usually straight, directly along the outside edge of each goalkeeper&#39;s restraining line so as to embody a unit of SF zone  112  and at curved elongated area directly along each edge of each goal area line so as likewise to embody a unit of zone  112  only when the supplemental impact characteristics meet the PP or CP expanded impact criteria for impact of a person&#39;s shoe. Controller  1114 / 1134  may cause color change at each goalkeeper&#39;s restraining line, or at each goal area line, embodying a unit of SF zone  892  when the supplemental impact characteristics meet the FR or CP expanded impact criteria for impact of a person&#39;s shoe. Impact of a ball, such as that used in team handball, on any of the goalkeeper&#39;s restraining and goal area lines and adjoining VC area portions usually does not cause a color change. 
     Jai alai is played on a rectangular court having a floor, a front wall, a left sidewall, a back wall, and sometimes a ceiling but no right sidewall. The top surface of the floor, the inside surfaces of the three walls, and the bottom surface of the ceiling, when present, embody surface  102 . The top of the floor has, for regulating certain aspects of jai alai, fourteen straight lines extending parallel to the front wall and numbered 1-14 starting from the front wall. The floor&#39;s top also has a straight right sideline extending parallel to the left sidewall. The inside of the front wall is divided into an interior rectangular portion of a first color, termed the interior color, and a ⊐-shaped peripheral portion of a second color, termed the peripheral color, different form the interior color. The peripheral portion adjoins the interior region along its entire top, entire right side, and entire bottom to define three straight zero-width lines respectively extending parallel to the top, right side, and bottom of the front wall. 
     A served pelota (ball) embodying object  104  in jai alai must impact inside the interior portion of the front wall, i.e., inside the inside edges of the three lines on the front wall, and then rebound so as to impact the floor beyond the inside (or front) edge of line  4 , in front of the outside (or back) edge of line  7 , and inside the inside (or left) edge of the floor&#39;s right sideline where “inside” is relative to the red portion of the front wall for the three front-wall lines, where “inside” (or front) and “outside” (or “back”) are relative to the front wall for lines  1 - 14 , and where “inside” (or “left”) is relative to the left sidewall for the floor&#39;s right sideline. The critical edges for the three front-wall lines are their inside edges. The critical edges for lines  4  and  7  are respectively their inside and outside edges. The critical edge for the floor&#39;s right sideline is its inside edge. 
     The CC capability is preferably at least provided as a unit of SF zone  112  at each of (a) three elongated front-wall areas, usually straight, respectively situated at least directly along the inside edges of the three front-wall lines, (b) two elongated areas, usually straight, respectively extending directly along the inside edge of line  4  and the outside edge of line  7 , and (c) elongated area, usually straight, extending directly along the inside edge of the floor&#39;s right sideline. The CC capability may also be provided as a unit of SF zone  892  at each of (a) three elongated areas of the peripheral front-wall portion directly along the inside edges of the three front-wall lines, (b) lines  4  and  7 , and (c) the floor&#39;s right sideline. 
     Platform tennis is played with paddles and a rubber ball on a wire-mesh enclosed court configured the same as, but smaller than, a regular tennis court. A platform tennis court, which has a net dividing the court into two half courts the same as a regular tennis court, is described in the same terminology as a regular tennis court except as follows. Singles sidelines  30 , servicelines  34 , centerline  36 , servicecourts  38 , and doubles sidelines  46  are respectively termed alley lines, service lines, center service line, service courts, and sidelines for a platform tennis court. The parts of the alley lines between the net and the service lines are termed service sidelines. The rules regarding the rubber ball being “in” and “out” in platform tennis are the same as for a tennis ball. The highest and next highest priority locations described above for the CC capability in a regular tennis court apply to a platform tennis court subject to the indicated terminology changes. 
     The CC capability is similarly provided as one or more units of SF zone  112  in area, usually elongated, directly along the critical edge of each of one or more finite-width lines used in many other sports including paddle tennis, Basque pelota, padel, paleta fronton, real tennis, soft tennis, and squash tennis. The CC capability may be provided as a unit of SF zone  892  directly at each of these lines. 
     As occurs in sports IP structure  1230 ,  1300 ,  1380 ,  1440 , and  1500 , the CC capability may optionally be provided as VC SF zone  912  (or  112 ) in area, usually elongated, directly along the edge, termed the non-critical edge, opposite the critical edge of each finite-width line used in squash, racketball, racquetball, handball, team handball, jai alai, platform tennis, paddle tennis, Basque pelota, padel, paleta fronton, real tennis, soft tennis, squash tennis, and many other sports. When the CC capability is provided at elongated area directly along the non-critical edge of any of these lines, the elongated area along the critical edge of each such line is usually at least as wide as, preferably wider than, the elongated area along the non-critical edge of that line. The width of the elongated area along the critical edge of each such line usually exceeds the width of the elongated area along the non-critical edge of that line by approximately the line&#39;s width. 
     The units of VC regions  106 ,  886 , and  906  for the preceding sports, including tennis, can be manufactured (a) as separate unicolor plates, each only having a unit of region  106 ,  886 , or  906  so as to be of only normal-state color A, B, or C or (b) as multicolor plates, each having units of regions  886  and  106  or/and  906 . Each multicolor plate is of normal-state colors B and A or/and C depending on whether that plate contains, in addition to a unit of region  886 , a unit of only one of regions  106  and  906  or a unit of both of regions  106  and  906 . If the multicolor plates contain cells  404  and  1084 , the plates can be cell programmed as described above for  FIG. 86  to define the location of the boundary of each unit of SF zone  892  with each adjoining unit of SF zone  112  on surface  102 . If they contain cells  404 ,  1084 , and  1104 , the multicolor plates can be cell programmed as described above for  FIG. 87  to define the locations of the boundaries of each unit of zone  892  with the adjoining units of SF zones  112  and  912  on surface  102 . 
     The units of VC regions  106 ,  886 , and  906  for these sports can also be removable VC units, e.g., unicolor or multicolor plates readily installed on, and removed from, substructure  134 . The removable VC units are installed on substructure  134  prior to a block of one or more sports activities for which the present CC capability is needed, removed from substructure  134  subsequent to the block of activities usually before surface  102  is used significantly for one or more activities not needing the CC capability, and so on with further installations and removals. The removable units can even be initially installed on substructure  134  as multiple unicolor plates and thereafter so removed and reinstalled as multicolor plates. If the depressions created in surface  102  due to the removal of the removable VC units would significantly affect activities not needing the CC capability, units of removable FC regions are installed on surface  102  at the locations of the removable VC units after their removal and removed from surface  102  before the removable VC regions are reinstalled on surface  102 . 
     Consecutive ones of the removable units meet smoothly along surface  102 . SF zones  112 ,  892 , and  912  of the removable VC units are largely coplanar with adjoining parts of surface  102 . To facilitate removal, the removable units usually have markings at their boundaries along surface  102 . The removable units for an embodiment of the units of VC regions  106 ,  886 , and  906  are usually rectangular in shape when two opposite boundaries of the unit of region  886  are parallel lines along surface  102 . Deterioration of the units of regions  106 ,  886 , and  906  is significantly reduced by implementing them as removable VC units used in the preceding way. This implementation and usage of regions  106 ,  886 , and  906  can, of course, be applied to activities other than sports. 
     Velocity Restitution Matching 
     The rebound characteristics of object  104  are preferably independent of where it impacts surface  102  in sports such as tennis where object  104  is in play after it initially rebounds off surface  102  during each stroke. In this section, object  104  is again termed ball  104  meaning a largely spherical hollow ball such as a tennis ball. During impact, ball  104  moves with its center of mass at a linear vector velocity V defined by (a) a linear scalar velocity (speed) V, (b) an inclination (vertical-plane) angle θ measured along a vertical plane perpendicular to surface  102  at approximately the center of total OC area  124  relative to a fixed reference line extending along that vertical plane and (c) an azimuthal (lateral-plane) angle φ measured along a lateral plane parallel to surface  102  at approximately the center of area  124  relative to a fixed reference line extending along that lateral plane. The reference line for inclination angle θ extends along the lateral plane for azimuthal angle φ. During impact, ball  104  is capable of rotating about its center of mass at an angular vector velocity  ω  having a scalar magnitude w. Letting subscript “i” mean incident, ball  104  impacts surface  102  with its center of mass at an incident linear vector velocity  V   i  and an incident angular vector velocity  ω   i  where incident linear vector velocity  V   i  is defined by an incident linear scalar velocity V i , an incident inclination angle θ i , and an incident azimuthal angle φ i . Letting subscript “r” similarly mean rebound, ball  104  rebounds from surface  102  with its center of mass at a rebound linear vector velocity  V   r  and a rebound angular vector velocity  ω   r  where rebound linear velocity  V   r  is defined by a rebound linear scalar velocity V r , a rebound inclination angle θ r , and a rebound azimuthal angle φ r . 
       FIG. 102 a    two-dimensionally illustrates how ball  104  deforms in impacting surface  102  here being a plane at an elevation angle α to a tangent to Earth&#39;s surface. The center  1600  of mass of ball  104  is located in the open space inside ball  104  since it is hollow. Ball  104 , moving from left to right, impacts surface  102  along an incident trajectory  1602  parallel to incident linear velocity  V   i  at impact time t ip . Ball  104  rebounds from surface  102  along a rebound trajectory  1604  parallel to rebound linear velocity  V   r  at OS time t os .  FIG. 102 a    employs a tilted Cartesian xyz coordinate system in which the x and y directions respectively extend parallel and perpendicular to surface  102 . The orthogonal direction is the y direction. The tangential direction is the direction which azimuthal angle φ defines along the xz plane during impact. Inasmuch as rebound azimuthal angle (Pr may differ from incident azimuthal angle (pi, the rebound tangential direction may differ from the incident tangential direction. The z direction, not indicated in  FIG. 102 a   , extends perpendicular to the plane of the figure toward the viewer. Symbol ω z  in  FIG. 102 a    indicates the component of angular velocity  ω  about the z direction, specifically the negative z direction. 
     The rebound characteristics formed with rebound linear velocity V r , rebound inclination angle θ r , rebound azimuthal angle φ r , and rebound angular velocity  ω   r  are preferably the same for any given set of incident characteristics formed with incident linear velocity V i , incident inclination angle θ i , incident azimuthal angle φ i , and incident angular velocity  ω   i  regardless of where ball  104  impacts surface  102 . A comparison of the rebound characteristics to the incident characteristics is provided by the coefficient (or ratio) e o  of orthogonal velocity restitution and the ratio e t  of tangential velocity restitution. Coefficient e o  of orthogonal velocity restitution equals V ry /V iy  where V ry  is the component of rebound linear velocity V r  in the positive y direction and V iy  is the component of incident linear velocity V i  in the negative y direction. Scalar velocities V iy  and V ry  are both positive here. Orthogonal velocity restitution coefficient e o  is largely a characteristic of the properties of ball  104  and the material forming surface  102  and generally depends only slightly on incident velocities  V   i  and  ω   i . 
     Ratio e t  of tangential velocity restitution equals V rt /V it  where V rt  is the component of rebound linear velocity V r  in the rebound tangential direction defined by rebound azimuthal angle φ r  and V it  is the component of incident linear velocity V i  in the incident tangential direction defined by incident azimuthal angle (pi. Incident tangential velocity component V it  and rebound tangential velocity component V rt  are:
 
 V   it =( V   ix   2   +V   iz   2 ) 1/2   (C1)
 
 V   rt =( V   rx   2   +V   rz   2 ) 1/2   (C2)
 
where V ix  and V iz  respectively are the components of incident velocity V i  in the positive x and z directions, and V rx  and V rz  respectively are the components of rebound velocity V r  in the positive x and z directions.
 
     Rebound linear vector velocity  V   r  at which ball  104  approaches a tennis player in the tangential and orthogonal directions in generally considerably more important than rebound angular vector velocity  ω   r  in the player&#39;s effort to successfully return ball  104 . Arranging for restitution parameters e o  and e t  to be independent of where ball  104  impacts surface  102  enables the rebound characteristics to be largely independent of the impact location in a practical sense. In other words, rebound location independence is largely achieved by having orthogonal coefficient e o  be approximately the same across surface  102  for the same conditions of incident vector velocities  V   i  and  ω   i  and by having tangential ratio e t  be approximately the same across surface  102  for the same  V   i  and  ω   i  conditions. 
     The impact causes ball  104  to flatten, i.e., compress in the y direction and usually expand in the x and z directions. A flattened part  1606  of ball  104  contacts surface  102  at total OC area  124 . A portion  1608 , indicated in dotted line, of flattened ball-contact part  1606  may separate from surface  102  during impact. The forces acting on ball  104  during impact consist of the gravitational force F m  caused by the ball&#39;s weight, the frictional force F f  resisting the ball&#39;s movement along surface  102  in the x and z directions, and the orthogonal force F o  exerted by surface  102  on ball  104  in the y direction. Gravitational force F m  equals mg where m is the mass of ball  104  and g is the acceleration of gravity. Force F m , although distributed throughout the mass of ball  104 , effectively acts at its mass center  1600 . Frictional force F f  and orthogonal force F o  are both distributed along area  124 . 
       FIG. 102 b    two-dimensionally illustrates a simplified model of ball  104  impacting surface  102  for analyzing the impact dynamics. The following assumptions are made for the model: (a) ball  104  remains spherical during impact so as to contact surface  102  at a single movable point  1610  during OC duration Δt oc , i.e., total OC area  124  devolves to contact point  1610 , (b) ball  104  moves only in the xy plane during impact so that z-direction tangential velocity components V iz  and V rz  are zero, (c) ball  104  rotates only about the z axis during impact so that angular velocity components in the x and y directions are zero, (d) gravitational force F m  acts through mass center  1600 , (e) point  1610  and center  1600  are in a straight line extending perpendicular to surface  102 , (f) orthogonal force F o  acts at point  1610  and thus in line with center  1600 , and (g) frictional force F f  acts at point  1610  only in the negative x direction. Angular velocity @ of ball  104  is formed solely with scalar angular velocity  ω   z  in the negative z direction. Scalar angular velocity  ω   z  is positive when ball  104  undergoes forward rotation, termed overspin or topspin, as depicted in the example of  FIG. 102 b    (and  FIG. 102 a   ) and negative when ball  104  undergoes backward rotation, termed underspin or backspin. Angular velocity ω z  has an incident component ω iz  and a rebound component ω rz . The terminologies used in the references cited below in this section have been converted into the preceding terminology. 
     Pallis, “Follow The Bouncing Ball Ball/Court Interaction”, The Tennis Server, Tennis Set, Part I, www.tennisserver.com/set/set_02_09.html, September 2002, 8 pp., Part II, www.tennisserver.com/set/set_02_10.html, October 2002, 21 pp., and Part III, www.tennisserver.com/set/set_02_11.html, November 2002, 20 pp., contents incorporated by reference herein, presents experimental data on incident velocity V i , incident angle θ i , rebound velocity V r , and rebound angle θ r  for tennis balls impacting four different types of tennis court surfaces at six different rates of incident spin, i.e., angular velocity ω iz , on the balls. The four courts respectively had a grass surface, a hard-court (often simply “hard”) surface, a red clay service, and a green clay surface. The six ω iz  spin rates were high underspin at roughly −2,500 rev/min, medium underspin at roughly −1,500 rev/min, none (flat) at roughly 0 rev/min, low overspin at roughly 900 rev/min, medium overspin at roughly 1,500 rev/min, and high overspin at roughly 3,000 rev/min. Elevation angle α was presumably largely zero for these courts. 
     Table 4 below presents the part of Pallis&#39;s experimental data on the four types of court surfaces using the same kind of standard tennis balls, namely Wilson U.S. Open tennis balls. Because Pallis presented velocity data in mi/hr, the velocity data has been converted to m/s in Table 4 followed parenthetically by the actual data in mi/hr. Table 4 also presents the values of orthogonal coefficient e o  and tangential ratio e t  calculated from Pallis&#39;s velocity/angle data. Coefficient e o , defined as V ry /V iy , was calculated as V r  sin θ r /V i  sin θ i . Ratio e t , defined as V rx /V ix , was calculated as V r  cos θ r /V i  cos θ i . For each court, Table 4 further presents the average value of coefficient e o  for the six ω iz  spin rates and the standard deviation from the average e o  value. 
                                                 TABLE 4                       Incid. Vel.   Incid.   Reb&#39;d Vel.   Reb&#39;d   Orth.   Tang.               V i  (m/s   Angle θ i     V r  (m/s   Angle θ r     Restit.   Restit.       Surface   Spin   (mi/hr))   (°)   (mi/hr))   (°)   Coef. e o     Ratio e t                    Grass   High under   14.8 (33)   23.1   7.2 (16)   29.1   0.60   0.46           Med. under   16.1 (36)   21.6   8.0 (18)   24.4   0.56   0.49           None   15.6 (35)   24.9   8.0 (18)   29.4   0.60   0.50           Low over   17.0 (38)   25.3   9.4 (21)   28.7   0.62   0.54           Med. over   17.4 (39)   22.8   10.7 (24)    23.2   0.63   0.61           High over   17.4 (39)   24.8   12.5 (28)    18.6   0.54   0.75           Average                   0.59           Stand. Dev.                   0.03       Hard   High under   12.5 (28)   20.6   7.2 (16)   29.7   0.80   0.53           Med. under   13.0 (29)   24.6   6.7 (15)   40.8   0.81   0.43           None   14.3 (32)   23.9   8.9 (20)   32.9   0.84   0.57           Low over   15.6 (35)   26.6   10.7 (24)    33.1   0.83   0.64           Med. over   16.5 (37)   21.9   12.5 (28)    27.4   0.93   0.72           High over   15.6 (35)   25.1   13.9 (31)    24.8   0.88   0.89           Average                   0.85           Stand. Dev.                   0.05       Red clay   High under   13.9 (31)   20.1   8.0 (18)   30.1   0.84   0.54           Med. under   13.9 (31)   23.7   7.6 (17)   37.9   0.83   0.47           None   13.0 (29)   26.5   8.0 (18)   37.5   0.85   0.55           Low over   13.9 (31)   25.5   9.4 (21)   34.4   0.89   0.62           Med. over   15.6 (35)   22.8   11.6 (26)    28.3   0.90   0.71           High over   16.1 (36)   24.1   13.4 (30)    24.5   0.84   0.83           Average                   0.86           Stand. Dev.                   0.03       Green   High under   10.3 (23)   20.8   5.8 (13)   31.5   0.83   0.52       clay   Med. under   14.3 (32)   25.1   7.6 (17)   39.9   0.78   0.45           None   14.8 (33)   26.8   8.9 (20)   37.5   0.82   0.54           Low over   15.2 (34)   27.5   10.3 (23)    35.5   0.85   0.62           Med. over   NA   NA   NA   NA   NA   NA           High over   16.5 (37)   28.0   13.9 (31)    27.7   0.83   0.84           Average                   0.82           Stand. Dev.                   0.03                    
Examination of the e o  and standard deviation data indicates that the average values of orthogonal coefficients e o  for the grass, hard, red clay, and green clay courts respectively were 0.59, 0.85, 0.86, and 0.82 with respective small standard deviations of 0.03, 0.05, 0.03, and 0.03.
 
     The foregoing average e o  values are consistent with Lindsey, “Follow the Bouncing Ball”, Racquet Sports Industry, April 2004, pp. 39-43, which reports orthogonal coefficients e o  of approximately 0.6, 0.83, and 0.85 for grass, hard, and clay tennis courts. Brody et al. (“Brody”),  The Physics and Technology of Tennis  (Racquet Tech Pub.), 2002, pp. 343-357, reports the same 0.83 and 0.85 e o  values respectively for hard and clay courts. Brody mentions that coefficient e o  decreases slightly with increasing incident orthogonal velocity V iy , at least when incident angle θ i  is approximately 90° and that coefficient e o  mysteriously increases slightly as angle θ i  decreases. Cross et al. (“Cross”), Technical Tennis (Racquet Tech Pub.), 2005, pp. 90-108, similarly reports e o  values of 0.80 and 0.85 respectively for hard and clay courts. 
     A composite of the e o  values reported by Lindsey, Brody, and Cross and calculated from Pallis&#39;s data indicates that orthogonal coefficient e o  is the same for typical hard and clay courts, namely approximately 0.85, and that coefficient e o  is approximately 0.60 for a typical grass court subject to slight decrease with increasing incident orthogonal linear velocity V iy , slight increase with increasing incident angle θ i , and slight dependence on initial ω iz  spin rate, the e o  values in Table 4 being slightly greater for moderate overspin than for the other spin rates. Percentage variations in coefficient e o  with linear velocity V iy , angle θ i , and initial ω iz  angular velocity are expected to be approximately the same for a grass court as for a hard or clay court. The percentage difference Δe o /e oav  between coefficient e o  for a typical hard or clay court and coefficient e o  for a typical grass court is somewhat greater than 30% for the same incident conditions, i.e., the same values of incident linear vector velocity  V   i  and incident angular vector velocity  ω   i , where Δe o  is the actual difference between the two e o  values, and e oav  is their average. 
     Grass, on one hand, and hard surface or clay, on the other hand, represent tennis-court extremes for orthogonal coefficient e o . Coefficient e o  across a court incorporating the present IP technology is preferably approximately fixed at a value ranging from a low of 0.60 for grass to a high of 0.85 for hard surface or clay. For the same incident conditions, the court acts more like grass than hard surface or clay when its e o  value is closer to 0.60 than to 0.85 and more like hard surface or clay than grass when its e o  value is closer to 0.85 than 0.60. In percentage terms at the same incident conditions, the court generally acts more like grass than hard surface or clay when its e o  value is no more than approximately 15% above 0.60 and more like hard surface or clay than grass when its e o  value is no more than approximately 15% below 0.85. 
     Orthogonal coefficient e o  is usually constant along VC SF zone  112 ,  892 , or  912  depending on which of zones  112 ,  892 , and  912 , hereafter simplified to zones  112  and  912  for the reasons given above, are present. Coefficient e o  is likewise usually constant along FC SF zone  114 ,  894 , or  914  depending on which of zones  114 ,  894 , and  914 , hereafter simplified to zones  114  and  894  for the above reasons, are present. However, coefficient e o  along zone  112  or  892  can differ from coefficient e o  along zone  114  or  894  because VC region  106  or  886  is constituted differently than FC region  108  or  888 . With the e o  data for typical grass, hard, and clay courts in mind, one factor in having the rebound characteristics be independent of the impact location entails having coefficient e o  along zone  112  or  892  differ by no more than 15%, preferably by no more than 10%, more preferably by no more than 5%, even more preferably by no more than 3%, yet even more preferably by no more than 2%, from coefficient e o  along zone  114  or  894  for ball  104  separately impacting zones  112  and  114  or  892  and  894  at identical conditions (values) of incident vector velocities  V   i  and  ω   i . By meeting this e o  specification, court areas such as VC court portions  1240 ,  1242 ,  1244 , and  1246  embodying zone  112  in tennis IP structure  1230  avoid approximating the e o  rebound characteristics of a typical grass court when court areas such as FC parts  1250 ,  1252 ,  1254 , and  1256  embodying zone  114  in structure  1230  have the e o  rebound characteristics of a typical hard or clay court, and vice versa. 
     Coefficient e o  may be considerably higher than 0.6 for some grass courts, e.g., 0.75 per Cross. By modifying the preceding e o  specification to require that coefficient e o  along VC SF zone  112  or  892  differ by no more than 5%, preferably by no more than 4%, more preferably by no more than 3%, even more preferably by no more than 2%, yet even more preferably by no more than 1%, from coefficient e o  along FC SF zone  114  or  894 , the modified e o  specification is applied to avoid having court areas such as VC court portions  1240 ,  1242 ,  1244 , and  1246  in IP structure  1230  approximate the e o  rebound characteristics of a grass court with an e o  value up to 0.75 when court areas such as FC parts  1250 ,  1252 ,  1254 , and  1256  in structure  1230  have the e o  rebound characteristics of a typical hard or clay court, and vice versa. 
     Subject to color B differing from color A, VC regions  106  and  886  are usually constituted the same when both are present. In view of this, orthogonal coefficient e o  along each VC SF zone  112  or  892  differs by no more than 5%, preferably by no more than 3%, more preferably by no more than 2%, even more preferably by no more that 1%, from coefficient e o  along each other zone  112  or  892  for ball  104  separating impacting zones  112  and  892  at identical conditions of vector velocities  V   i  and  ω   i . FC regions  108  and  888  are likewise usually constituted in the same way when both are present. Coefficient e o  along each FC SF zone  114  or  894  differs by no more than 5%, preferably by no more than 3%, more preferably by no more than 2%, even more preferably by no more that 1%, from coefficient e o  along each other zone  114  or  894  for ball  104  separately impacting zones  114  and  894  at identical  V   i  and  ω   i  conditions. 
     Ball  104  slides or/and rolls while it contacts surface  102  during an impact. In particular, ball  104  usually begins an impact by sliding and may complete the impact by sliding or rolling. In the model of  FIG. 102 b   , contact point  1610  is instantaneously motionless during rolling as ball  104  rotates around it. Frictional force F f  is much greater during sliding than rolling. 
     Frictional force F f  insofar as it is directed in the negative x direction causes ball  104  to slow down and thereby causes rebound tangential velocity V rx  to decrease. Tangential ratio e t  generally increases as force F f  in the negative x direction decreases and vice versa. Referring again to Table 4, the values of ratio e t  calculated from Pallis&#39;s data generally increase as incident angular velocity ω iz  increases, i.e., as the spin goes from high underspin to high overspin. This seemingly occurs because (i) the tennis balls undergo both sliding and rolling during impact at the incident conditions examined in Pallis and (ii) increasing incident angular velocity ω iz  causes rolling to occur progressively earlier during impact so that the total amount of force F f  in the negative x direction progressively decreases. 
     Grass presents less friction than hard surface or clay. The e t  values in Table 4 show, with a few exceptions, that tangential ratio e t  is considerably lower for grass than for hard surface or clay at any particular ω iz  spin value consistent with frictional force F f  being lower for grass than hard surface or clay. Hence, ratio e t  can be used to distinguish the rebound characteristics of grass from those of hard surface or clay. 
     Clay courts are generally perceived as being “slower” than hard courts, i.e., frictional force F f  is seemingly greater for clay than hard surface at the same  V   i  and  ω   i  conditions. Tangential ratio e t  should be lower for clay than hard surface. However, the e t  values in Table 4 at any particular ω iz  spin value are generally not significantly different. The so-calculated e t  values do not provide a basis for distinguishing between the rebound characteristics of hard surface and clay. This lack of differentiation may arise because rolling occurs much more than sliding during impact at Pallis&#39;s incident conditions, especially the values of incident angle θ i , all 20° or more. 
     Cross mentions that tennis balls only slide during impact when incident angle θ i  is sufficiently small, less than 20°, perhaps considerably less than 20°. Consider the dynamics of the sliding-only situation. Frictional force F f  is then the force of sliding friction. The total force F x  in the (positive) x direction is −F f +F m  sin α. The total force in the (positive) y direction is F o −F m  cos α. Frictional force F f  and normal force F o  respectively are:
 
 F   f   =−F   x   +F   m  sin α  (C3)
 
 F   o   =F   y   +F   m  cos α  (C4)
 
The average coefficient μs of sliding friction during OC duration Δt oc  is:
 
                     μ   s     =         ∫   0     Δ   ⁢           ⁢     t   oc         ⁢       F   f     ⁢   dt           ∫   0     Δ   ⁢           ⁢     t   oc         ⁢       F   o     ⁢   dt                 (   C5   )               
Combining Eqs. C3 and C4 into Eq. C5 leads to:
 
     
       
         
           
             
               
                 
                   
                     μ 
                     s 
                   
                   = 
                   
                     
                       
                         
                           ∫ 
                           0 
                           
                             Δ 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               t 
                               oc 
                             
                           
                         
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 - 
                                 
                                   F 
                                   x 
                                 
                               
                               + 
                               
                                 
                                   F 
                                   m 
                                 
                                 ⁢ 
                                 sin 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 α 
                               
                             
                             ) 
                           
                           ⁢ 
                           dt 
                         
                       
                       
                         
                           ∫ 
                           0 
                           
                             Δ 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               t 
                               oc 
                             
                           
                         
                         ⁢ 
                         
                           
                             ( 
                             
                               
                                 F 
                                 y 
                               
                               + 
                               
                                 
                                   F 
                                   m 
                                 
                                 ⁢ 
                                 cos 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 α 
                               
                             
                             ) 
                           
                           ⁢ 
                           dt 
                         
                       
                     
                     = 
                     
                       
                         
                           - 
                           
                             
                               ∫ 
                               0 
                               
                                 Δ 
                                 ⁢ 
                                 
                                     
                                 
                                 ⁢ 
                                 
                                   t 
                                   oc 
                                 
                               
                             
                             ⁢ 
                             
                               
                                 F 
                                 x 
                               
                               ⁢ 
                               dt 
                             
                           
                         
                         + 
                         
                           
                             F 
                             m 
                           
                           ⁢ 
                           Δ 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             t 
                             oc 
                           
                           ⁢ 
                           sin 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           α 
                         
                       
                       
                         
                           
                             ∫ 
                             0 
                             
                               Δ 
                               ⁢ 
                               
                                   
                               
                               ⁢ 
                               
                                 t 
                                 oc 
                               
                             
                           
                           ⁢ 
                           
                             
                               F 
                               y 
                             
                             ⁢ 
                             dt 
                           
                         
                         + 
                         
                           
                             F 
                             m 
                           
                           ⁢ 
                           Δ 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           
                             t 
                             oc 
                           
                           ⁢ 
                           cos 
                           ⁢ 
                           
                               
                           
                           ⁢ 
                           α 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   C6 
                   ) 
                 
               
             
           
         
       
     
     Evaluating the integrals using Newton&#39;s second law that force equals the time derivative of momentum and therefore that the time integral of force equals the change in momentum, and substituting mg for gravitational force F m  yields: 
                     μ   s     =           -     m   ⁡     (       V   rx     -     V   ix       )         +     m   ⁢           ⁢   g   ⁢           ⁢   Δ   ⁢           ⁢     t   oc     ⁢   sin   ⁢           ⁢   α           m   ⁡     (       V   ry     +     V   iy       )       +     m   ⁢           ⁢   g   ⁢           ⁢   Δ   ⁢           ⁢     t   oc     ⁢   cos   ⁢           ⁢   α         =         V   ix     -     V   rx     +     g   ⁢           ⁢   Δ   ⁢           ⁢     t   oc     ⁢   sin   ⁢           ⁢   α           V   iy     +     V   ry     +     g   ⁢           ⁢   Δ   ⁢           ⁢     t   oc     ⁢   cos   ⁢           ⁢   α                   (   C7   )               
OC duration Δt oc  is typically several ms, invariably less than 10 ms, when ball  104  is a tennis ball. The term gΔt oc  cos α in the denominator of Eq. C7 is a very small percent, usually considerably less than 1%, of the orthogonal velocity denominator summation term V iy +V ry  for V iy  and V ry  values during a tennis match. Elevation angle α is usually very close to zero for a tennis court. The term gΔt oc  sin α in the numerator of Eq. C7 is likewise a very small percent, usually considerably less than 1%, of the tangential velocity numerator difference term V ix −V rx  for V ix  and V rx  values during a tennis match. Sliding friction coefficient μ s  is then closely approximated as:
 
     
       
         
           
             
               
                 
                   
                     μ 
                     s 
                   
                   = 
                   
                     
                       
                         V 
                         ix 
                       
                       - 
                       
                         V 
                         rx 
                       
                     
                     
                       
                         V 
                         iy 
                       
                       + 
                       
                         V 
                         ry 
                       
                     
                   
                 
               
               
                 
                   ( 
                   C8 
                   ) 
                 
               
             
           
         
       
     
     Overall tangential velocity components V it  and V rt  respectively equal x-direction tangential velocity components V ix  and V rx  since z-direction tangential velocity components V iz  and V rz  are assumed to be zero. Tangential ratio e t  equals V rx /V ix . Applying this relationship and the relationship that orthogonal coefficient e o  equals V ry /V iy  to Eq. C8 results in: 
                     μ   s     =           (     1   -     e   t       )     ⁢     V   ix           (     1   +     e   o       )     ⁢     V   iy         =       (       1   -     e   t         1   +     e   o         )     ⁢           ⁢   cot   ⁢           ⁢     θ   i                 (   C9   )               
where the ratio V ix /V iy  is the cotangent of incident angle θ i . Solving Eq. C9 for tangential ratio e t  yields:
 
 e   t =1−μ s (1+ e   o )tan θ i   (C10)
 
     In addition to the characteristics of the material forming surface  102 , sliding friction coefficient μ s  depends on dynamic factors, including incident vertical velocity V iy . Various μ s  values are reported for grass, hard, and clay court for various incident conditions. For the same incident conditions, the μ s  value for clay exceeds the μ s  value for hard surface which exceeds the μ s  value for grass. Various references, e.g., Brody, report μ s  values of 0.8, 0.7, and 0.6 respectively for clay, hard, and grass courts, presumably at the same incident conditions. 
     Table 5 below shows how tangential ratio e t  varies with incident angle θ i  for grass, hard surface, and clay having the preceding μ s  values and the preceding respective e o  values of 0.60, 0.85, and 0.85. For comparison purposes, Table 5 also shows how ratio e t  varies with incident angle θ i  for hard surface having μ s  and e o  values of 0.7 and 0.80. Three values, 12°, 16°, and 20°, of angle θ i  are used in Table 5. A tennis ball is generally expected to slide without rolling when angle θ i  is 12° or 16° and may slide without rolling when angle θ i  is 20°. 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 5 
               
               
                   
               
               
                   
                 Sliding 
                 Orthogonal 
                 Inci- 
                 Tangen- 
                 Percentage 
               
               
                   
                 Friction 
                 Restitution 
                 dent 
                 tial 
                 Diff. 
               
               
                 Sur- 
                 Coeffi- 
                 Coeffi- 
                 Angle 
                 Restitution 
                 Hard-clay 
               
               
                 face 
                 cient μ s   
                 cient e o   
                 θ i  (°) 
                 Ratio e t   
                 Δe t /e tav   
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Clay 
                 0.8 
                 0.85 
                 12 
                 0.69 
                   
               
               
                   
                   
                   
                 16 
                 0.58 
               
               
                   
                   
                   
                 20 
                 0.46 
               
               
                 Hard 
                 0.7 
                 0.85 
                 12 
                 0.72 
                 4 
               
               
                   
                   
                   
                 16 
                 0.63 
                 8 
               
               
                   
                   
                   
                 20 
                 0.53 
                 14 
               
               
                 Hard 
                 0.7 
                 0.80 
                 12 
                 0.73 
                 6 
               
               
                   
                   
                   
                 16 
                 0.64 
                 10 
               
               
                   
                   
                   
                 20 
                 0.54 
                 16 
               
               
                 Grass 
                 0.6 
                 0.60 
                 12 
                 0.80 
               
               
                   
                   
                   
                 16 
                 0.72 
               
               
                   
                   
                   
                 20 
                 0.65 
               
               
                   
               
            
           
         
       
     
     As Table 5 indicates, tangential ratio e t  varies considerably with incident angle θ i  for any particular type of court surface. The International Tennis Federation indicates in “ITF Approved Tennis Balls, Classified Surfaces &amp; Recognised Courts, a Guide to Products &amp; Test Methods”, part B, sect. 4, www.itftennis.com/media/165935/165935.pdf, 2014, pp. 37-40, that it uses 16° as a reference value of angle θ i  for assessing court friction and restitution characteristics. At the 16° θ i  reference value, ratio e t  is approximately 0.58 for a clay court and approximately 0.63 or 0.64 for a hard court depending on whether its e o  value is 0.85 or 0.80. 
     Table 5 presents the percentage difference Δe t /e tav  between tangential ratio e t  for a hard court and ratio e t  for a clay court at each 0 value where Δe t  is the actual difference between the two e t  values, and e tav  is their average. Hard-clay percentage difference Δe t /e tav  increases with increasing incident angle θ i . At the 16° θ i  reference value, hard-clay percentage difference Δe t /e tav  is approximately 8% or 10% depending on whether the e o  value for a hard court is 0.85 or 0.80. Ratio e t  is approximately 8-10% higher for a typical hard court than a typical clay court at 16° incidence. For the same incident impact conditions including 16° incidence, a court acts more like hard surface than clay when its e t  value is closer to 0.63 or 0.64 than to 0.58 and more like clay than hard surface when its e t  value is closer to 0.58 than 0.63 or 0.64. In percentage terms at the same incident conditions including 16° for incident angle θ i , the court acts more like hard surface than clay when its e t  value is above 0.63-0.64 or no more than 4-5% below 0.63-0.64 and more like clay than hard surface when its e t  value is below 0.58 or no more than 4-5% above 0.58. 
     The 0.58 and 0.63 or 0.64 e t  values for clay and hard surface at 16° incidence are based on the simplified model of  FIG. 102 b   . While actual e t  values for clay and hard surface at 16° incidence may respectively differ somewhat from 0.58 and 0.63 or 0.64, tangential ratio e t  is still expected to be approximately 8-10% higher for typical hard surface than typical clay at 16° incidence using the actual e t  values. A court acts more like hard surface than clay when its ratio e t  is above the actual e t  value for hard surface or no more than 4-5% below the actual hard-surface e t  value and more like clay than hard surface when its ratio e t  is below the actual e t  value for clay or no more than 4-5% above the actual clay e t  value. 
     Tangential ratio e t  is usually the same along VC SF zone  112  or  892  for any particular θ i  value, e.g., the 16° reference value, depending on which of zones  112  and  892  are present. Ratio e t  is likewise usually the same along FC SF zone  114  or  894  for any particular θ i  value depending on which of zones  114  and  894  are present. However, ratio et along zone  112  or  892  can differ from ratio et along zone  114  or  894  for any particular 08 value because VC region  106  or  886  is constituted differently than FC region  108  or  888 . With the e t  data for typical hard and clay courts in mind, another factor in having the rebound characteristics be independent of the impact location entails having ratio et along zone  112  or  892  differ by no more than 5%, preferably by no more than 4%, more preferably by no more than 3%, even more preferably by no more than 2%, yet even more preferably by no more than 1%, from ratio et along zone  114  or  894  for ball  104  separately impacting zones  112  and  114  or  892  and  894  at identical conditions (values) of incident vector velocities  V   i  and  ω   i  at 16° for incident angle θ i . By meeting this e t  specification, court areas such as VC court portions  1240 ,  1242 ,  1244 , and  1246  in tennis IP structure  1230  avoid having the e t  rebound characteristics of a typical clay court when court areas such as FC parts  1250 ,  1252 ,  1254 , and  1256  in structure  1230  have the e t  rebound characteristics of a typical hard court and vice versa. 
     A standard clay tennis court is usually largely covered with loose particles whose maximum average diameter is several mm. Some of these particles invariably migrate over the units of SF zones  112  and  912  in a clay tennis court provided with the present CC capability. It is expected that the presence of these particles on the units of VC SF zones  112  and  892  will cause tangential ratio et along zone  112  or  892  to approach ratio et along FC SF zone  114  or  894 . 
     The characteristics of SF structures  242  and  962  variously in OI structures  240 ,  260 ,  270 ,  320 ,  330 ,  440 ,  450 ,  460 ,  490 ,  500 ,  960 ,  980 ,  990 , and  1010  can readily be chosen to achieve the preceding e o  and e t  matching between VC SF zone  112  or  892  and FC SF zone  114  or  894 . For instance, the material defining zone  114  or  894  can be an SF layer of the same material and the same thickness, and thus the same sliding friction coefficient μ s  and light transmissivity, as SF structure  242  or  962 . If structure  242  or  962  consists of multiple layers, the material along zone  114  or  894  can consist of multiple layers respectively identical material-wise and thickness-wise to, and in the same order as, the layers of structure  242  or  962 . The two or more layers along zone  114  or  894  then have the same sliding friction coefficient μ s  and light transmissivity, as structure  242  or  962 . The presence of structures  242  and  962  thus facilitates having the rebound characteristics of ball  104  be independent of where it impacts surface  102 . Also, the layer directly below this SF layer or two or more layers along zone  114  or  894  largely defines color A′ or B″ that FC region  108  or  888  appears along zone  114  or  894 . 
     Variations 
     While the invention has been described with reference to particular embodiments, this description is solely for the purpose of illustration and is not to be construed as limiting the scope of the claimed invention. For instance, the above timing and color-difference parameters can be presented in spectral radiance terms in which the wavelength variation of the power present in light is characterized by its spectral radiance L eλ  instead of its spectral radiosity JA. Subject to replacing maximum value J pmax  of radiosity parameter J p  with a corresponding maximum value for a corresponding radiance parameter, the relationships given above for approximate times t fs , t fe , t rs , and t re  can be used with spectral radiance L eλ  replacing spectral radiosity J λ . The minimum values presented above for full XN delays Δt f  and Δt r , CC duration Δt dr , 50% XN delays Δt f50  and Δt r50 , 90% XN delays Δt f90  and Δt r90 , and 10%-to-90% XN delays Δt f10-90  and Δt r10-90  carry over to the situation where spectral radiance L eλ  replaces spectral radiosity J λ . 
     If VC region  106  in OI structure  130 ,  240 ,  280 , or  320  is installed on substructure  134  after being manufactured, region  106  can include an installation/protective layer extending along substructure  134 . CC component  184  in OI structure  180  or  260  can include an installation/protective layer, embodied with FA layer  206  in OI structure  200  or  270 , extending along substructure  134  if region  106  is separately manufactured. Each installation/protective layer, used for installing region  106  on substructure  134 , protects the adjacent ISCC material from damage during the time period between the manufacture of region  106  and its installation on substructure  134 . Each of VC regions  886  and  906  in OI structure  920  or  960  can include such an installation/protective layer, embodied with FA layer  946  of region  886  in OI structure  930  or  980 , situated along substructure  134 . 
     DE structure  282  in OI structure  280  or  320  can also include an installation/protective layer extending along substructure  134  for installing VC region  106  on substructure  134  if region  106  is separately manufactured. This installation/protective layer protects the DE and ISCC material from damage during the period between the manufacture of region  106  and its installation on substructure  134 . If VC regions  886  and  906  in OI structure  990  are separately manufactured, each DE structure  992  or  994  can include such an installation/protective layer situated along substructure  134 . 
     Instead of having PP IDVC portion  138  in OI structure  280  or  300  change color directly in response to the deformation along SF DF area  122  meeting the above-mentioned PP basic SF DF criteria, portion  138  can change color in response to the PP general CC control signal generated in response to the deformation along area  122 , specifically print area  118 , meeting the basic SF DF criteria sometimes dependent on other impact criteria, typically the PP supplemental impact criteria, also being met. The same applies to portion  138  and, subject to appropriate control signal and criteria changes, AD IDVC portion  926  and the FR IDVC portion in variations of OI structure  990  or  1110  lacking SF structures  242 ,  962 , and  964 . Rather than have portion  138  in OI structure  320  or  330  change color directly in response to the deformation along internal DP IF area  256  meeting the above-mentioned PP basic internal DF criteria, portion  138  can change color in response to the PP general CC control signal generated in response to the deformation along area  256 , specifically IF segment  256 , meeting the basic internal DF criteria sometimes dependent on other impact criteria, again typically the PP supplemental impact criteria, also being met. The same applies to portion  138  and, subject to appropriate control signal and criteria changes, AD IDVC portion  926  and the FR IDVC portion in OI structure  990  or  1110 . 
     Rather than have each CM cell  404  in OI structure  470  or  480  change color directly in response to the deformation along that cell&#39;s SF part  406  meeting the above-mentioned PP cellular SF DF criteria, each CM cell  404  can change color in response to its cellular CC control signal generated in response to the deformation its SF part  406  meeting the cellular SF DF criteria sometimes dependent on other impact criteria, typically the PP supplemental impact criteria, also being met. The same applies to CM cells  404  and, subject to appropriate control signal and criteria changes, CM cells  1084  and  1104  in cellular embodiments of variations of OI structure  990  or  1110  lacking SF structures  242 ,  962 , and  964 . Instead of having each CM cell  404  in OI structure  490  or  500  change color directly in response to the deformation along that cell&#39;s IF part  444  meeting the above-mentioned PP cellular internal DF criteria, each CM cell  404  can change color in response to its cellular CC control signal generated in response to the deformation along its IF part  444  meeting the cellular internal DF criteria sometimes dependent on other impact criteria, likewise typically the PP supplemental impact criteria, also being met. The same applies to CM cells  404  and, subject to appropriate control signal and criteria changes, CM cells  1084  and  1104  in cellular embodiments of OI structure  990  or  1110 . 
     DE structures  282  and  302  can be replaced with structures directly responsive to excess pressure. The same applies to the DE parts of cells  404 ,  1084 , and  1104 . If substructure-reflected ARsb or XRsb light exits SF zone  112  in any of the four general embodiments of CC component  184  based on light-reflection changes or in any of the six general embodiments of component  184  based on light-emission changes, ARsb light is included in each total light determination for VC region  106  during the normal state, and XRsb light is included in each total light determination for IDVC portion  138  during the changed state. 
     The object tracking provided by IG structure  804  can be performed by a non-optical technique, e.g., a Doppler-shift technique such as radar or sonar. Rather than track the movement of object  104  and generate a moving image that follows the movement of object  104 , structure  804  can provide an image of surface  102  as object  104  moves over surface  102  and then zoom in on object  104  at OC area  116 . 
     When IG structure  804  generates PP PAV images as described above, CC controller  832  or  852  can sometimes be deleted in a variation of IP structure  830  or  850 . IP structure  1150  (or  1170 ) or  1180  (or  1200 ) can be modified the same as IP structure  800  (or  830 ) or  840  (or  850 ) subject to changing OI structure  100  or  400  to OI structure  900  or  1100 , IG controller  806  or  846  to IG controller  1154  or  1184 , PP LI impact signals to PP, AD, and FR LI impact signals, print area  118  to print areas  118 ,  898 , and  918 , SF zone  112  to SF zones  112 ,  892 , and/or  912 , a PP PAV image to a PP, AD, FR, or CP PAV image, and CC controller  832  or  852  to CC controller  1114  or  1134 . 
     The capability to selectively activate and deactivate the VC strips can be extended beyond tennis. In general, each of two or more different VC parcels of the VC structure formed with at least one of VC regions  106 ,  886 , and  906  can be selectively activated and deactivated at selected times. Subject to each VC parcel consisting of material of the VC structure different from each other VC parcel, each VC parcel may include one or more portions of the VC structure present in one or more other VC parcels. One of the VC parcels may consist of the entire VC structure. The time periods during which two or more of the VC parcels are activated may partly or fully overlap. 
     The selective activation and deactivation of the VC parcels is controlled with a suitable switch located on CC controller  1114 / 1134  or separate from it for communicating with it remotely via a COM path. A person can operate the switch manually or by voice. IG structure  804 , again specifically image-collecting apparatus  808 , can provide controller  1114 / 1134  with images of activities occurring along surface  102 . Controller  1114 / 1134  employs a shape-recognition capability for recognizing shapes present in those images and, when specified shapes are recognized, automatically selectively activates and deactivates the VC parcels at selected times. Apparatus  808  may then include separate components for respectively collecting PAV images and images of other activities occurring along surface  102 . 
     CC controller  1114 / 1134  may consist of separate units, including one for the (optional) sound-generation capability. CC controller  832 ,  852 ,  1114 , or  1134  and IG controller  806 ,  846 ,  1154 , or  1184  can be merged into one controller. OI structure  900  or  1100  can be extended to include more than three VC regions variously laterally adjoining one another. 
     A particular implementation of intelligent controller  702  or  752  can respond to different embodiments of object  104 , e.g., a person&#39;s foot and a ball such as a tennis ball, impacting (the same embodiment of) VC SF zone  112  sufficient to cause the PP supplemental impact criteria to be generated by having the supplemental impact criteria formulated as respective different PP supplemental impact criteria groups to which the PP general supplemental impact information is compared to determine if it meets any of these criteria groups and, if so, for providing the PP general CC initiation signal or PP cellular CC initiation signals for causing the PP IDVC portion ( 138 ) to temporarily undergo color change at print area  118 . Changed color X can be the same for all the criteria groups or different for at least two of the criteria groups. The same applies to CC controller  832  or  852  when it is implemented as controller  702  or  752 . A particular implementation of CC controller  1114  or  1134  functioning as an intelligent controller akin to controller  702  or  752  can operate in the same way subject to changing VC SF zone  112 , the PP supplemental impact criteria, the different PP supplemental impact criteria groups, the PP general CC initiation signal, the PP cellular CC initiation signals, the PP IDVC portion, and print area  118  respectively to VC SF zones  112 ,  892 , and  912 , the PP, AD, FR, and CP supplemental impact criteria, different PP, AD, FR, and CP supplemental impact criteria groups, the PP, AD, and FR general CC initiation signals, the PP, AD, and FR cellular CC initiation signals, the PP, AD, and FR IDVC portions, and print areas  118 ,  898 , and  918 . 
     In tennis matches using linespersons to (initially) decide whether tennis balls are “in” or “out”, the most difficult in/out decisions on groundstroked balls are often on balls impacting surface  102  on or close to baselines  28  because the balls are moving roughly perpendicular to the lines of vision of the specific linespersons making the decisions. The present CC capability is limited, in a singles/doubles variation of tennis IP structure  1260 , to ␣-shaped VC OB area portions  1276  or to the parts of portions  1276  along baselines  28 . In a singles-only variation of structure  1260  lacking alleys  48 , the CC capability is limited to the parts of OB portions  1276  along shortened baselines  28  and potentially also to VC singles HA area portions  1274  that become parts of OB portions  1276  in this variation. Limiting the CC capability to OB area in any of these ways avoids any need for velocity restitution matching. This is especially attractive for grass courts where it may be difficult to achieve good velocity restitution matching between VC IB court portions  1270 ,  1272 ,  1274 , and  1276 , on one hand, and FC IB court parts  1280 ,  1282 , and  1284 , on the other hand. Although only a partial solution to improved line calling, limiting the CC capability in any of these ways may be a good compromise between keeping the CC-capability implementation cost down while overcoming a serious line-call problem. 
     The present CC capability can generally be used in situations (a) where two SF zones of different colors meet to form a zero-width line at their interface and (b) a SF zone is sandwiched between two SF zones of different color than the sandwiched zone. A major example of the sandwiched zone is a finite-width line, such as a line on a sports playing area, which can be straight or curved or various combinations of straight and/or curved lines. The CC capability can be used in numerous non-sports situations, e.g., in a carpet to track and record the path of a person undergoing a drunk-driving walking test. The CC capability is generally best suited for indoor usage to avoid harsh weather conditions but can be used outdoors. Object  104 , although usually moving through air, can be employed in situations where it moves through gas whose constituency differs from standard air. Object  104  can move through a substantial vacuum in some situations. 
     In order to distinguish between impacts by object  104  and impacts by bodies not intended to cause color change, the material forming surface  102  can be of a nature as to cause color change only when the outside surface of an impacting body has the chemical, electrical, or/and intensive physical properties of the outside surface of object  104 . Exemplary intensive physical properties include texture and hardness. This characteristic of the material forming surface  102  can, for example, be used to distinguish between impact of a shoe and impact of a ball such as a tennis ball, basketball, or volleyball because a shoe almost invariably has different chemical, electrical, or/and intensive physical properties than a ball. 
     The words “principal”, “additional”, and “further” and their acronyms “PP”, “AD”, and “FR” as used in differentiating VC regions  106 ,  886 , and  906 , corresponding SF zones  112 ,  892 , and  912 , the TH impact criteria, the supplemental impact criteria, and the expanded impact criteria are arbitrary and can be variously interchanged. The PP, AD, FR, and CP PAV images can be described as close-up images. When OC areas  896  and  116  or/and  916  are continuous with one another, they can be described as a single OC area. When print areas  898  and  118  or/and  918  are continuous with one another, they similarly can be described as a single print area. Various modifications may be made by those skilled in the art without departing from the true scope of the invention as defined by the claims.