Abstract:
A method and apparatus for displaying a three-dimensional picture is disclosed. The picture display apparatus includes a display device for displaying a three-dimensional picture, a pointing device for pointing a position in the picture displayed in the display device, a holding device for holding the control information of a plurality of possible stop points pre-determined in a three-dimensional space, and a control device for causing the three-dimensional picture to be displayed on the display device based on the control information of the possible stop points in the three-dimensional space held by the holding device. The possible stop points correspond to positions in the picture pointed by the pointing device. The producer of a virtual reality can easily reflect the intention of a three-dimensional virtual reality, while the-user can easily walk in the three-dimensional virtual reality.

Description:
RELATED APPLICATION 
     This is a divisional application of application No. 08/658,506 filed on Jun. 5, 1996, now issued as U.S. Pat. No. 6,028,609. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to method and apparatus for displaying a three-dimensional picture. 
     2. Description of Related Art 
     A server computer, as a central information processing apparatus, and a client computer, as a user terminal information processing apparatus, maybe interconnected using a cable, a telephone line or a network, for purveying the information in the server computer to the user client computer, or retrieving the information in the server computer from the user client computer, It is recently practiced to represent the virtual reality three-dimensionally, as a conceptual model or metaphoric representation for information purveying services on a display device of the client computer which is capable of displaying graphics. Thus the user is able to use or retrieve the information purveying services in a form similar to reality. 
     Specifically, a variety of objects or equipments, such as desks, shelves, television receivers or doors, exist in the virtual reality. The user points the direction of movement in the three-dimensional virtual reality, using a pointing device, such as a mouse, trackball or a keypad, and moves within the displayed three-dimensional virtual reality for acting on the objects or the equipments within the three-dimensional virtual reality. 
     When the user moves in the three-dimensional virtual reality, he or she is free to move in an optional direction. Thus it is difficult for the user to realize in which direction he or she is to move or which objects or equipments will be encountered. 
     On the other hand, since the three-dimensional virtual reality is represented on a two-dimensional display device, that is a CRT display, it is difficult to reflect the intention of a producer who has produced the three-dimensional virtual reality. 
     If the user has moved to a position in the three-dimensional virtual reality not intended by the producer, the field of view of the user becomes incomprehensible such that he or she is unable to realize in which direction he or she is to move next. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a picture display method and apparatus in which the user feels free to move and it is possible to represent a picture of the three-dimensional virtual reality so as to reflect the intention of the producer. 
     In one aspect, the present invention provides a picture display apparatus including display means for displaying a three-dimensional picture, pointing means for pointing a position in the picture displayed in the display means, holding means for holding the control information of a plurality of possible stop points pre-determined in a three-dimensional space, and control means for causing the three-dimensional picture to be displayed on the display means based on the control information of the possible stop points in the three-dimensional space held by the holding means. These possible stop points correspond to positions in the picture pointed by the pointing means. 
     In another aspect, the present invention provides a picture display method including displaying a three-dimensional picture on a display device and displaying the three-dimensional picture on the display device based on the control information on predetermined possible stop points in a three-dimensional space corresponding to positions in the picture pointed by pointing means adapted for pointing a position in the picture. 
     According to the present invention, if a pre-set position in a picture displayed on a display device is pointed to by a pointing device, the control device manages control for displaying a three-dimensional picture on the display device based on the position information, line of sight information, speed information and the operational information of the possible stop points pre-set in association with the pointed to position. The information of these various sorts are held by the holding device. The inside of the three-dimensional virtual reality may be displayed easily, while the user can easily walk through the inside of the three-dimensional virtual reality. 
     In addition, the producer of the three-dimensional virtual reality can easily reflect the intention of production with a smaller data volume. Since the operation of the human being in the three-dimensional virtual reality can be assimilated to the operation of the human being in the real world, the user can easily move through the inside of the three-dimensional virtual reality so that the picture seen during such movement can be rendered analogous to a picture as encountered during movement of a human being in the real world. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic view showing an arrangement of a system inclusive of a client computer having a picture display apparatus according to the present invention. 
     FIG. 2 is a schematic view showing an arrangement of a client computer having a picture display apparatus according to the present invention. 
     FIGS. 3A and 3B illustrate dwell points and pass points. 
     FIGS. 4A and 4B illustrate the user&#39;s operation and viewing point. 
     FIGS. 5A,  5 B and  5 C illustrate viewing angles. 
     FIG.6 illustrates a first embodiment of the user&#39;s operation and viewing point in the three-dimensional virtual reality. 
     FIG. 7 shows a picture viewed by the user. 
     FIG. 8 shows another picture viewed by the user. 
     FIG. 9 shows still another picture viewed by the user. 
     FIG. 10 illustrates a viewing point of the user. 
     FIG. 11 illustrates a second embodiment of the user&#39;s operation and viewing point in the three-dimensional virtual reality. 
     FIG. 12 shows a picture viewed by the user. 
     FIG. 13 shows a picture viewed by the user. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings, preferred embodiments of the present invention will be explained in detail. 
     Before proceeding to a description of the illustrative contents of the present invention, the overall system inclusive of the picture display apparatus according to the present invention will be explained by referring to FIGS. 1 and 2. 
     In the system of the present embodiment, an on-line terminal device  2 , which is an information processing apparatus according to the present invention, as a client computer, is connected via a large-scale ATM (asynchronous transmission mode) network  3 , a relay  4 , and a fiber distribution data interface (FDDI)  5 , to a service management server  13 , a video server  12  and a service AP server  14 , which are service purveying side on-line servers, as shown in FIG.  1 . The asynchronous transmission mode (ATM) divides the transmission data into plural fixed-length data, that is plural 48-byte-based data, irrespective of data types, and appends a 5-byte header, inclusive of the information on the address of the destination of data transmission, to the fixed-length data, in order to transmit data in terms of data units called “cells” each made up of 53 bytes. These cells, fed into the ATM network  3 , are switched by the ATM switcher based on the header information. On arrival at the receiving terminal, the cells are restored to the original data based on the header information. The ATM network can transmit speech, moving pictures and computer data in admixture. The FDDI is a medium accessing system of a 100 Mbit/second token passing system employing optical fibers. 
     The video server  12  is comprised of a data storage device  6 , made up of the server computer  7  and a data storage device  6 , such as a hard disc or an optical disc. In the data storage device  6  is stored digital video data processed into a format, such as MPEG format as later explained. The digital video data is read out from the data storage device  6  of the video server  12  for transfer in response to a request from the client computer  2 . 
     The service AP server  14  is similarly comprised of a server computer  11  and a data storage unit  10 . In the data storage unit  10 , data or scripts which form the basis of a three-dimensional picture as application (AP) program data is stored. From the data storage device  10  of the service AP server  14 , the application program data is read out for transfer in response to the request from the client computer  2 . 
     The service management server  13  is similarly comprised of a server computer  9  and a data storage device  8 . The service management server  13  accepts requests from the client computer  2  and controls or manages the video server  7  or the service AP server  11  in response to the requests. 
     It is possible to provide plural video servers  12  and plural service AP servers  14 , or to assemble the servers  12  to  14  in a single server. 
     The requests transferred through the ATM network  3  are transmitted to a server via a device for doing protocol conversion, termed relay  4 , relay  4  performs automatic data distribution and data transfer speed conversion, and via the FDDI interface  5 . 
     The data sent from the server in response to the requests from the client computer  2  is processed for display by the client computer  2  so as to be displayed on the display of the monitor. This completes a graphical user interface (GUI), that is a user interface employing the graphic display. Thus the user may operate or receive services as he or she views the graphic display on the monitor device  1 . 
     The client computer  2  shown in FIG. 1 is arranged as shown in FIG.  2 . 
     Referring to FIG. 2, the EISA board  36  is a board for communication which interconnects the client computer  2  and the ATM network  3 . The signals supplied from the ATM network  3  to the EISA board  36  are transiently stored in the hard disc  43  which is controlled as to data reading and data writing by the processing unit  41 . The signals are then read out depending on data sorts and supplied to the three-dimensional rendering engine  34 , MPEG2 decoder  35 , PC audio decoder  39  and to the MPEG2 audio decoder  40 . 
     The  3 D rendering engine  34  is a coordinate converter for converting three-dimensional coordinate data of a three-dimensional object into data for display on the display  20  of the monitoring device  1 . That is, three dimensional coordinate data is turned into picture data in the three-dimensional virtual reality. That is, the 3D rendering engine  34  is designed to construct the graphical user interface (GUI) conforming to the application. 
     The MPEG2 decoder  35  is a decoder for expanding data compressed by the MPEG2 standard. Meanwhile, MPEG (Moving Picture Experts Group)  2  is an international standard for the technique of compression and expansion of moving pictures. 
     Since data from the 3D rendering engine  34  and data from the MPEG2 decoder  35  are both data of three prime colors of red (R), green (G) and blue (B), the RGB mixer  33  generates data which is a mixture of these three colors R, G and B. 
     The NTSC encoder  32  converts data from the RGB mixer  33  into signals of the television standards of NTSC (National Television System Committee) system. The video signals from the NTSC encoder  32  are displayed on the display  20  of the monitoring device  1 . On the display  20  in the present embodiment, shown in FIG. 2, there are displayed the pointer (cursor)  22  by the pointing device, a picture  23  obtained on decoding MPEG2 data and a picture for GUI produced by the 3D rendering engine  34 , such as the three-dimensional or two-dimensional picture  21 . The picture from the MPEG2 and the picture for GUI may be synthesized for display. 
     The PC audio decoder  39  generates, for example, the effect sound, using an ADPCM (adaptive differential pulse code modulation) sound source. The MPEG2 audio decoder.  40  expands audio data compressed by MPEG2. The data from the PC audio decoder  39  and the data from the MPEG2 audio decoder  40  are mixed by the audio mixer  38  into audio signals which are sent to a speaker  30 . The output sound from the speaker  30  is preferably stereo sound or multi-channel sound. Use may be made of a recently developed system in which a sound image may be three-dimensionally fixed by controlling the phase difference of the stereo sound. 
     The operation on the display  20  employing GUI is executed using the pointing device, for example, a wireless air mouse  31 . The coordinate data transmitted by a radio route by electrical waves from the wireless air mouse  31  is received by a wireless tuner  37 . The received coordinate data is sent to the processing unit  41 . The pointing device  31  may also be a usual mouse, trackball, joystick or a touch panel associated in the coordinate positions thereof with the display  20 , in place of the wireless air mouse  31 . Of course, a variety of pointing devices, such as usual mouse, trackball, keypad, joystick or a touch panel, having coordinate positions corresponding in coordinate positions to the display, may also be provided as data entry means for the pointing device  31 . 
     The processing unit  41  has a central processing unit (CPU), and controls various component elements over a bus based on program data stored in the program ROM of the memory  42  having the function of both the program ROM and the work RAM. The processing unit also controls the GUI based on coordinate data from the wireless air mouse  31  and occasionally executes the communication with the server computer. Although the 3D rendering engine  34  and the MPEG2 decoder  35  are provided as independent chips in the embodiment of FIG. 2, signal processing by these components may also be performed by software on the above processing unit  41 . 
     The illustrative operation of on-line service purveying to the user by using the system of FIGS. 1 and 2 is now explained. 
     The user first instructs connection on the network of the client computer  2  to the server computer, herein the computer  9  of the service management server  13 , using the pointing device of the client computer  2 . 
     When the connection on the network is completed and the request is supplied from the client computer  2 , the computer  9  of the service management server  13  on the server side is responsive to the request to control the video server  12  and the service AP server  14  to transfer data and software to the client computer  2 . The data and software, thus transferred, are those required for processing, and may be enumerated by scripts stating the behavior of the virtual reality space, three-dimensional coordinate data and sound data in the virtual reality space and scripts stating alternatives instructed from the client computer  2  to the user. 
     The client computer  2  presents the virtual reality space, derived from the data and the software received from the server side, using the screen of the display  20  of the monitor device  1  and occasionally the speaker  30 . 
     The user strolls in the inside of the virtual reality space presented on the client computer  2 , as he or she views the virtual reality space and instructs the direction of movement and so forth. The user also operates on a component or installation in the virtual reality space by actuating an operating button or the like provided on the pointing device. 
     The client computer  2  is responsive to the user actuation by the viewing point position, viewing line direction, speech and the operation or behavior of the components in the virtual reality space in accordance with the scripts, and presents the virtual reality space to the user, with the aid of the speaker  30  and the display  20  of the monitoring device  1 , as though the user were present in the virtual reality space. The client computer  2  is also responsive to the statement of the scripts to present a variety of information items or give advice to the user or place an order for the user. 
     The picture display apparatus according to the present invention is provided in the above-mentioned client computer  2 , and includes the monitoring device  1 , as display means for displaying a three-dimensional picture, the wireless mouse  31  as pointing device for indicating a position in the picture displayed on the monitoring device  1 , and holding means for holding the information on the positions of plural possible pre-set stop points in a three-dimensional space, the information on the line of sight, the information on the speed and the information on the operation. The picture display apparatus also includes the processor  41 , as control means for controlling the monitor device  1  to display the three-dimensional picture on the monitoring device  1 . The picture display apparatus displays the three-dimensional picture based on the information on the positions of plural possible pre-set stop points in a three-dimensional space, the information on the line of sight, the information on the speed and the information on the operation in the three-dimensional space, held by the holding means, in association with the positions in the picture as pointed by the wireless mouse  31 . The holding means is the hard disc  43  or a memory  42 . If the above information of various sorts is transmitted from the server, and are not stored on the hard disc  43  or in the memory  42 , the holding means correspond to the data storage units  6 ,  8  and  10 . 
     In order to permit the user to move in the three-dimensional virtual reality displayed by the above picture display apparatus, plural points are pre-set in which the user is allowed to dwell in the three-dimensional virtual reality. These plural points are termed dwell points. By actuating the wireless mouse  31  and pointing to a desired position or object in the picture representing the three-dimensional virtual reality, the user may move to and dwell at one of the dwell points in the three-dimensional virtual reality. By moving through plural dwell points, the user may move through the inside of the three-dimensional virtual reality. The picture viewed by the user as he or she moves through the inside of the three-dimensional virtual reality is displayed on the picture display apparatus. 
     Referring to FIGS. 3A and 3B, the dwell points are explained in detail. 
     FIGS. 3A and 3B show a three-dimensional picture looking at shelves  51 ,  52  for commercial products in a store in the three-dimensional virtual reality from the oblique transverse direction and from above, respectively. FIGS. 3A and 3B also show plural dwell points  61  to  65  by black circles, movable relative to the shelves for products  51  and  52  in the store. The direction of the lines of sight of the user at these dwell points  61  to  65  are indicated by solid-line arrows. 
     When the user moves from a given dwell point to another dwell point, the dwell point to which the user can move is determined as the operational information of the dwell point, as will be explained subsequently. That is, the user can move only to the dwell points to which the user can move next based on the information on operation set at the given dwell point. However, the user cannot move to any other points, that is to any places where the dwell points are not provided in the three-dimensional virtual reality. For example, the user at the dwell point  62  can move only to the dwell points  61  or  63 . 
     There are occasions wherein pass points, that is points to be passed through, are set between two dwell points. The pass points are the points indicating the positions to be passed through during movement between two dwell points, and also indicating the directions of the lines of sight. The user cannot stop at these pass points even on indication by the wireless mouse  31  and can only pass through these points. When moving from the dwell point  64  to the dwell point  65  or from the dwell point  65  to the dwell point  64  in the store of the three-dimensional virtual reality, the user must necessarily pass through the pass points  71  and  72 . Plural control information items are set in these pass points  71 ,  72 , as in the dwell points. The directions of the lines of sight of the user in these pass points  71 ,  72  are indicated by solid-line arrows in FIGS. 3A and 3B. 
     The control information items set in the dwell points and in the pass points include the position information, line of sight information, speed information and operational information. The position information is the values of the position in a three-dimensional coordinate system. The line of sight information includes the direction of the line of sight, rolling angle of the line of sight, and the visibility angle. The speed information includes the maximum value of the movement speed, maximum value of the rotational angular velocity of the direction of line of sight, maximum value of the rotational angular velocity of the rolling angle of the line of sight, and the maximum value of the increasing velocity of the angle of visibility. The operation information includes the state of the operation to be performed next. 
     The rolling angle corresponds to an angle of rotation when an airplane, for example, gyrates in a three-dimensional space. The operational information is written in scripts and is specifically the operation produced by the user actuating the wireless mouse  31  for moving the pointer, pointing to the position or object and clicking the button within a picture viewed by the user stopped at a dwell point. The operation information is such information for permitting the user to move to the next dwell point or open the door to enter the store in the three-dimensional virtual reality. 
     Since it is possible that plural dwell points or pass points have the same information items, pre-set values (default values) may be provided for respective information items. If the information at a given dwell point or at a given pass point is the same as the information at a dwell point or pass point to which the user moves next, the information at the given dwell point or at the given pass point may be inherited so as to be directly used as the information for the dwell point or pass point to which the user moves next. 
     Meanwhile, the points in the three-dimensional virtual reality other than the dwell points and the pass points (inner points) and the position information and line of sight information at the inner points are found by interpolation of the information at the neighboring dwell points and pass points. 
     During movement from a given dwell point or a given pass point to the next dwell point or pass point, the speed information set in the given dwell point or pass point is used. As for position movement, the movement occurs linearly at a constant speed not exceeding the maximum value of the movement speed. As for the direction of line of sight, rotation occurs at a constant speed not exceeding the maximum value of the rotational angular velocity. As for the rolling angle of the line of sight, rotation occurs at a constant speed not exceeding the maximum value of the rotational angular velocity of the rolling angle of the line of sight. Finally, as for the angle of visibility, it is increased at a constant rate not exceeding the maximum value of the rate of increase of the angle of visibility. 
     By interpolation of the inner points and the position information and line of sight information at these inner points, it becomes possible to smooth the display of the movement operation from a given dwell point or a given pass point to the next dwell point or the next pass point. That is, the picture displayed on the display unit  20  becomes analogous in picture quality to the picture viewed by the user on actual movement. 
     The movement and the line of sight of the user with the use of the dwell and pass points are now explained specifically. 
     It is assumed that the user moves from a dwell point  81 , the direction of line of sight for which is as indicated by a solid-line arrow in FIG. 4A, to a dwell point  82 , the direction of line of sight for which is set as shown by a solid-line arrow, that is  180  opposite to that at the dwell point  81 . The change in the line of sight, in which the direction of line of sight is moved at a constant rate in the sequence of solid-line arrows  83 ,  84  an  85 , is different from the change in the line of sight of the human being in the real world. Thus a pass point  86 , for which the direction of line of sight is set so as to be the same as that of the direction of the line of sight at the dwell point  82 , is provided in the vicinity of the dwell point  81 , as shown in FIG.  4 B. Thus, if the user moves from the dwell point  81  to the dwell point  82 , the direction of the line of sight is set at the pass point  86  so as to be the same as that at the dwell point  82 , after which movement occurs to the dwell point  82 . The movement of the line of sight occurs based on the speed information set at the dwell point  81 . 
     By passing through the pass point  86  in moving from the dwell point  81  to the dwell point  82 , the user first turns round before starting walking, thus simulating the operation of the human being in the three-dimensional virtual reality. The displayed picture becomes more analogous to the picture viewed by the human being in the actual world. 
     The angle of visibility may be set from one dwell point to another. By changing the angle of visibility, it becomes possible to change the amount of the information included in the picture of the same size. When the human being moves from within a house  500  to outdoors, as shown in FIG. 5A, the angle of visibility at a dwell point  502  is set so as to be wider than that at a dwell point  501 . In this manner, the picture viewed by the user, that is the picture displayed on the display  20 , at the dwell point  501 , is a picture including buildings  503  and  504  shown in FIG.  5 B. However, the picture viewed by the user on movement to the dwell point  502  is such a picture in which the perspective feeling is accentuated such that the buildings  503 ,  504  become smaller and mountains  505 ,  506  are also visible, thus representing the open outdoor feeling, as shown in FIG.  5 C. 
     The information on picture data representing the three-dimensional virtual reality, dwell point and pass points is sent from the server of FIG. 1 via an ATM network  3  to the client computer  2 . The processor  41  of the client computer controls the user movement in the three-dimensional virtual reality based on the information on the dwell and pass points, and causes the picture from the viewing points of the moving user to be displayed on the display  20 . The information on the dwell and pass points, sent from the server, is recorded on the hard disc  43  or stored in the memory  42 . 
     A first embodiment of the operation and the line of sight of the user in the three-dimensional virtual reality is explained in detail. 
     FIG. 6 shows a two-dimensional picture looking into a given three-dimensional virtual reality from above. In this three-dimensional virtual reality, there are plural stores  301  to  306 ,  308  and  310 , from which to obtain a variety of information purveying services, on both sides of the user, who walks straight between the plural stores. 
     It is assumed that the user is at a standstill at a dwell point  309   1 . The directions of the line of sight of the user is indicated by a solid-line arrow, while the movement operation of the user is indicated by a broken line arrow. 
     At this dwell point  309   1 , the user can move in any one of the forward, left and right directions. The picture viewed by the user at the dwell point  309   1  is displayed on the display  20 . This picture is shown in FIG.  7 . The user sees left-hand side stores  302 ,  303 ,  308  and right-hand side stores  305 ,  306 ,  310 . 
     The pointer is changed in shape or pattern depending on the position it occupies in the picture displayed on the display  20  and specifies the operation that can be done next by its position. That is, the pointer performs navigation by the pointer shape with regard to the operation to be done at the position of the pointer. Thus, by clicking the button of the wireless mouse  31  when the pointer is at a position in the display  20 , the operating state indicated by the pointed shape is entered. 
     That is, by moving the pointer to a pre-set area and clicking the button of the wireless mouse  31 , the next operation is performed under control by the processor  41  based on the operation information at the dwell point. By such operation, the picture viewed by the user is displayed on the display  20 . It should be noted that the area in the picture in which the button of the wireless mouse  31  can be clicked is predetermined, such that, if the pointer moved to an area other than such predetermined area is clicked, the next operation is not entered by control of the processor  41 . 
     In the picture of FIG. 7, the user can perform the next operation if he or she moves the pointer to one of the positions indicated by the forward arrow pointer  401 , left arrow pointer  402  and the right arrow pointer  403  and clicks the button of the wireless mouse  31 . The pointer shape at each position specifies the operation to be performed next at each position, that is, movement in the forward direction, towards left or towards right. 
     If the user clicks the left arrow pointer  402 , he or she moves to a dwell point  309   2  shown in FIG.  6 . The picture seen by the user at this time is shown in FIG.  8 . The user stands at a position spaced from the store  302 . The line of sight of the user is directed to the store  302 . Thus the user sees five stores  301 ,  302 ,  303 ,  307  and  308 , in place of the three left side stores he or she viewed at the dwell point  309   1 . The possible movement direction at this dwell point  309   2  is one of the directions specified by the forward arrow pointer  404 , left arrow pointer  402  and the right arrow pointer  403  in the picture shown in FIG.  8 . If, in the picture of FIG. 8, the user actuates the wireless mouse  31  to move the pointer and clicks the button at a position of the forward arrow pointer  404 , the user moves to a dwell point  309   3  in FIG.  6 . If the user clicks the button at the left arrow pointer  405  or at the right arrow pointer  406 , the user moves to dwell points  309   4  or  309   5  in FIG. 6, respectively. 
     If, in the picture of FIG. 8, the user clicks the button at the forward arrow pointer  404 , moves and is halted, he or she views a picture shown in FIG.  9 . The dwell point  309   3  lies directly ahead of the store  302  so that the user sees three stores  301 ,  302  and  303 . In this picture, the user can move the pointer to one of a pointer  409  specifying the opening of the door of the store  302 , left arrow pointer  407 , right arrow pointer  408  and a pointer  410  specifying the return to the position of the original dwell point  309   2  (zoom-back) in order to click the button of the wireless mouse  31 . For example, if the button is clicked at the position of the pointer  409 , access may be had to the service contents of the store  302 . The contents of services offered by the store  302  may be previewed automatically by characters or pictures at a time point when the pointer is moved to the position of the pointer  409 . 
     In the above-described first embodiment, the user is free to move because of a larger number of dwell points. 
     A second embodiment of the operation and viewing point of the user in the three-dimensional virtual reality is now explained. 
     Referring first to FIG. 10, the viewing point of the user is explained. 
     In the previous embodiment, the user walks straight between both rows of stores. The direction of line of sight of the user is the same as the walking direction. Conversely, while the user walks in a direction indicated by an arrow A in FIG. 10, the direction of the line of sight is not the same as the walking direction but is set at an angle θ towards one of the rows of stores. This angle θ is on the order of 30 to 60°. In the example of FIG. 10, the line of sight of the user  105  is inclined 30 to 60° towards the row of the stores  301 ,  302 ,  303  and  308 , so that the user has a field of view W. 
     FIG. 11 shows a two-dimensional picture for the row of the stores  301  to  303  as well as the operation and the line of sight of the user. The user initially is halted at the dwell point  105   1  in FIG.  11 . The directions of the line of sight and the movement operation of the user are indicated by a solid-line arrow and a broken-line arrow, respectively. 
     The picture the user sees at the dwell point  105   1  is represented on the display  20  and is a picture shown in FIG.  12 . The user sees the stores  301 ,  302  and  303 . 
     The user moves the pointer of the wireless mouse to one of the positions indicated by the forward arrow pointer  201 , left arrow pointer  202  or the store  301 , right arrow pointer  203  or the store  303  and clicks the button for entering the next operation. If the button is clicked at the position of the forward arrow pointer  201 , the user moves to a dwell point  105   2  in FIG.  11 . That is, the user moves automatically to a position directly ahead of the store  302 , with the store  302  being at the center of the field of view. If the button is clicked at the left arrow pointer  202  or at the position of the store  301 , the user moves automatically to a position directly ahead of the store  301 , with the store  301  being at the center of the field of view. If the button is clicked at the right arrow pointer  203  or at the position of the store  303 , the user moves automatically to a position directly ahead of the store  303 , with the store  303  being at the center of the field of view. 
     FIG. 3 shows a picture the user views at the dwell point  105   2 . The picture of FIG. 13 is the same as the picture shown in FIG.  9 . Thus, with the present second embodiment, the user can move to the dwell point  105   2  of FIG. 11, which is the same as the dwell point  309   3  of FIG. 6, by a single movement operation. 
     In the picture of FIG. 13, similarly to the picture shown in FIG. 9, the pointer can be moved to one of the pointer  204  specifying the opening of the door of the store  302 , left arrow pointer  205 , right arrow pointer  206  and the pointer  207  specifying reversion to the position of the original dwell point  105   1  (zoom-back) by clicking the button of the wireless mouse  31 . By clicking the button at the position of the pointer  204 , access may be had to the contents of services offered by the store  302 . The contents of the services of the store  302  can be automatically previewed with characters or pictures at a time when the pointer has been moved to the position of the pointer  204 . If the button is clicked at the position of the pointer  207  for zoom-back to the dwell point  105   1 , the direction of the line of sight, for example, is also reverted to the original state, so that the picture seen by the user is the picture shown in FIG.  12 . 
     By setting the dwell points or pass points, in which the position information, line of sight information, speed information and the operational information, convenient for the user, have been set, as in the instant second embodiment, the user can easily judge the direction of movement, for example, in the movement operation in the three-dimensional virtual reality.