Patent Publication Number: US-9417763-B2

Title: Three dimensional user interface effects on a display by using properties of motion

Description:
BACKGROUND 
     It&#39;s no secret that video games now use various properties of motion and position collected from, e.g., compasses, accelerometers, gyrometers, and Global Positioning System (GPS) units in hand-held devices or control instruments to improve the experience of play in simulated, i.e., virtual, three dimensional (3D) environments. In fact, software to extract so-called “six axis” positional information from such control instruments is well-understood, and is used in many video games today. The first three of the six axes describe the “yaw-pitch-roll” of the device in three dimensional space. In mathematics, the tangent, normal, and binormal unit vectors for a particle moving along a continuous, differentiable curve in three dimensional space are often called T, N, and B vectors, or, collectively, the “Frenet frame,” and are defined as follows: T is the unit vector tangent to the curve, pointing in the direction of motion; N is the derivative of T with respect to the arclength parameter of the curve, divided by its length; and B is the cross product of T and N. The “yaw-pitch-roll” of the device may also be represented as the angular deltas between successive Frenet frames of a device as it moves through space. The other three axes of the six axes describe the “X-Y-Z” position of the device in relative three dimensional space, which may also be used in further simulating interaction with a virtual 3D environment. 
     Face detection software is also well-understood in the art and is applied in many practical applications today including: digital photography, digital videography, video gaming, biometrics, surveillance, and even energy conservation. Popular face detection algorithms include the Viola-Jones object detection framework and the Schneiderman &amp; Kanade method. Face detection software may be used in conjunction with a device having a front-facing camera to determine when there is a human user present in front of the device, as well as to track the movement of such a user in front of the device. 
     However, current systems do not take into account the location and position of the device on which the virtual 3D environment is being rendered in addition to the location and position of the user of the device, as well as the physical and lighting properties of the user&#39;s environment in order to render a more interesting and visually pleasing interactive virtual 3D environment on the device&#39;s display. 
     Thus, there is need for techniques for continuously tracking the movement of an electronic device having a display, as well as the lighting conditions in the environment of a user of such an electronic device and the movement of the user of such an electronic device—and especially the position of the user of the device&#39;s eyes. With information regarding lighting conditions in the user&#39;s environment, the position of the user&#39;s eyes, and a continuous 3D frame-of-reference for the display of the electronic device, more realistic virtual 3D depictions of the objects on the device&#39;s display may be created and interacted with by the user. 
     SUMMARY 
     The techniques disclosed herein use various position sensors, e.g., a compass, a Micro-Electro-Mechanical Systems (MEMS) accelerometer, a GPS module, and a MEMS gyrometer, to infer a 3D frame of reference (which may be a non-inertial frame of reference) for a personal electronic device, e.g., a hand-held device such as a mobile phone. Use of these position sensors can provide a true Frenet frame for the device, i.e., X- and Y-vectors for the display, and also a Z-vector that points perpendicularly to the display. In fact, with various inertial clues from an accelerometer, gyrometer, and other instruments that report their states in real time, it is possible to track the Frenet frame of the device in real time, thus providing a continuous 3D frame of reference for the hand-held device. Once the continuous frame of reference of the device is known, the techniques that will be disclosed herein can then either infer the position of the user&#39;s eyes, or calculate the position of the user&#39;s eyes directly by using a front-facing camera. With the position of the user&#39;s eyes and a continuous 3D frame-of-reference for the display, more realistic virtual 3D depictions of the objects on the device&#39;s display may be created and interacted with. 
     To accomplish a more realistic virtual 3D depiction of the objects on the device&#39;s display, objects may be rendered on the display as if they were in a real 3D “place” in the device&#39;s operating system environment. In some embodiments, the positions of objects on the display can be calculated by ray tracing their virtual coordinates, i.e., their coordinates in the virtual 3D world of objects, back to the user of the device&#39;s eyes and intersecting the coordinates of the objects with the real plane of the device&#39;s display. In other embodiments, virtual 3D user interface (UI) effects, referred to herein as “2½D” effects, may be applied to 2D objects on the device&#39;s display in response to the movement of the device, the movement of the user, or the lighting conditions in the user&#39;s environment in order to cause the 2D objects to “appear” to be virtually three dimensional to the user. 
     3D UI Effects Achievable Using this Technique 
     It is possible, for instance, using a 2½D depiction of a user interface environment to place realistic moving shines or moving shadows on the graphical user interface objects, e.g., icons, displayed on the device in response to the movement of the device, the movement of the user, or the lighting conditions in the user&#39;s environment. 
     It is also possible to create a “virtual 3D operating system environment” and allow the user of a device to “look around” a graphical user interface object located in the virtual 3D operating system environment in order to see its “sides.” If the frame of reference is magnified to allow the user to focus on a particular graphical user interface object, it is also possible for the user to rotate the object to “see behind” it as well, via particular positional changes of the device or the user, as well as user interaction with the device&#39;s display. 
     It is also possible to render the virtual 3D operating system environment as having a recessed “bento box” form factor inside the display. Such a form factor would be advantageous for modular interfaces. As the user rotated the device, he or she could look into each “cubby hole” of the bento box independently. It would also then be possible, via the use of a front-facing camera, to have visual “spotlight” effects follow the user&#39;s gaze, i.e., by having the spotlight effect “shine” on the place in the display that the user is currently looking into. It is also possible to control a position of a spotlight effect based solely on a determined 3D frame of reference for the device. For example, the spotlight effect could be configured to shine into the cubby hole whose distorted normal vector pointed the closest in direction to the user of the device&#39;s current position. 
     Interaction with a Virtual 3D World Inside the Display 
     To interact via touch with the virtual 3D display, the techniques disclosed herein make it possible to ray trace the location of the touch point on the device&#39;s display into the virtual 3D operating system environment and intersect the region of the touch point with whatever object or objects it hits. Motion of the objects caused by touch interaction with the virtual 3D operating system environment could occur similarly to how it would in a 2D mode, but the techniques disclosed herein would make it possible to simulate collision effects and other physical manifestations of reality within the virtual 3D operating system environment. Further, it is possible to better account for issues such touchscreen parallax, i.e., the misregistration between the touch point and the intended touch location being displayed, when the Frenet frame of the device is known. 
     How to Prevent the GPU from Constantly Re-Rendering 
     To prevent the over-use of the Graphics Processing Unit (GPU) and excessive battery drain on the device, the techniques disclosed herein employ the use of a particularized gesture to turn on the “virtual 3D operating system environment” mode, as well as positional quiescence to turn the mode off. In one embodiment, the gesture is the so-called “princess wave,” i.e., the wave-motion rotation of the device about one of its axes. For example, the “virtual 3D operating system environment” mode can be turned on when more than three waves of 10-20 degrees along one axis occur within the span of one second. 
     In one embodiment, when the “virtual 3D operating system environment” mode turns on, the display of the UI “unfreezes” and turns into a 3D depiction of the operating system environment (preferably similar to the 2D depiction, along with shading and textures indicative of 3D object appearance). When the mode is turned off, the display could slowly transition back to a standard orientation and freeze back into the 2D or 2½D depiction of the user interface environment. Positional quiescence, e.g., holding the device relatively still for two to three seconds, could be one potential cue to the device to freeze back to the 2D or 2½D operating system environment mode and restore the display of objects to their more traditional 2D representations. 
     Desktop Machines as Well 
     On desktop machines, the Frenet frame of the device doesn&#39;t change, and the position of the user with respect to the device&#39;s display would likely change very little, but the position of the user&#39;s eyes could change significantly. A front-facing camera, in conjunction with face detection software, would allow the position of the user&#39;s eyes to be computed. Using field-of-view information for the camera, it would also be possible to estimate the distance of the user&#39;s head from the display, e.g., by measuring the head&#39;s size or by measuring the detected user&#39;s pupil-to-pupil distance and assuming a canonical measurement for the human head, according to ergonomic guidelines. Using this data, it would then be possible to depict a realistic 2½D or 3D operating system environment mode, e.g., through putting shines on windows, title bars, and other UI objects, as well as having them move in response to the motion of the user&#39;s eyes or the changing position of the user&#39;s head. Further, it would also be possible to use the position of the user&#39;s head and eyes to allow the user to “look under” a window after the user shifts his or her head to the side and/or moves his or her head towards the display. 
     Because of innovations presented by the embodiments disclosed herein, the 3D UI effects utilizing properties of motion that are described below may be implemented directly by a personal electronic device&#39;s hardware and/or software, making the techniques readily applicable to any number of personal electronic devices, such as mobile phones, personal data assistants (PDAs), portable music players, televisions, gaming consoles, portable gaming devices, as well as laptop, desktop, and tablet computers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an exemplary prior art personal electronic device. 
         FIG. 2  illustrates an exemplary 3D UI technique that may be employed by a personal electronic device operating in a 2½D operating system environment mode. 
         FIG. 3  illustrates a personal electronic device presenting a virtual 3D depiction of a graphical user interface object lit by a virtual light source, in accordance with one embodiment. 
         FIG. 4  illustrates a personal electronic device presenting a virtual 3D depiction of a graphical user interface object lit by a representative ambient light source, in accordance with one embodiment. 
         FIG. 5  illustrates the Frenet frame for a personal electronic device, in accordance with one embodiment. 
         FIG. 6  illustrates the effects of device movement on a personal electronic device presenting a virtual 3D depiction of a graphical user interface object, in accordance with one embodiment. 
         FIG. 7  illustrates the effects of user movement on a personal electronic device presenting a virtual 3D depiction of a graphical user interface object, in accordance with one embodiment. 
         FIG. 8  illustrates a recessed, “bento box” form factor inside the virtual 3D display of a personal electronic device, in accordance with one embodiment. 
         FIG. 9  illustrates a point of contact with the touchscreen of a personal electronic device ray traced into a virtual 3D operating system environment, in accordance with one embodiment. 
         FIG. 10  illustrates an exemplary gesture for activating the display of a personal electronic device to operate in a virtual 3D operating system environment mode, in accordance with one embodiment. 
         FIG. 11  illustrates, in flowchart form, one embodiment of a process for operating a personal electronic device in a virtual 3D operating system environment mode. 
         FIG. 12  illustrates, in flowchart form, one embodiment of a process for toggling a personal electronic device between operating in a virtual 3D operating system environment mode and a non-virtual 3D operating system environment mode. 
         FIG. 13  illustrates, in flowchart form, one embodiment of a process for projecting spotlights indicative of the position of a user&#39;s eyes into a virtual 3D operating system environment of a personal electronic device. 
         FIG. 14  illustrates, in flowchart form, one embodiment of a process for implementing graphical user interface effects on the display of a personal electronic device based on ambient light sources detected in the environment of the device and/or the relative position of the device. 
         FIG. 15  illustrates a simplified functional block diagram of a personal electronic device, in accordance with one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure pertains to techniques for continuously tracking the movement of an electronic device having a display, as well as lighting conditions in the environment of a user of such an electronic device and the movement of the user of such an electronic device—and especially the position of the user of the device&#39;s eyes. With the position of the user&#39;s eyes and a continuous 3D frame-of-reference for the display of the electronic device, more realistic virtual 3D depictions of the objects on the device&#39;s display may be created and interacted with. While this disclosure discusses a new technique for creating more realistic virtual 3D depictions of the objects on a personal electronic device&#39;s display, one of ordinary skill in the art would recognize that the techniques disclosed may also be applied to other contexts and applications as well. The techniques disclosed herein are applicable to any number of electronic devices with positional sensors, proximity sensors, and/or digital image sensors: such as digital cameras, digital video cameras, mobile phones, personal data assistants (PDAs), portable music players, televisions, gaming consoles, portable gaming devices, desktop, laptop, and tablet computers, and game controllers. An embedded processor, such a Cortex® A8 with the ARM® v7-A architecture, provides a versatile and robust programmable control device that may be utilized for carrying out the disclosed techniques. (CORTEX® and ARM® are registered trademarks of the ARM Limited Company of the United Kingdom.) 
     In the interest of clarity, not all features of an actual implementation are described in this specification. It will of course be appreciated that in the development of any such actual implementation (as in any development project), numerous decisions must be made to achieve the developers&#39; specific goals (e.g., compliance with system- and business-related constraints), and that these goals will vary from one implementation to another. It will be appreciated that such development effort might be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill having the benefit of this disclosure. Moreover, the language used in this disclosure has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter, resort to the claims being necessary to determine such inventive subject matter. Reference in the specification to “one embodiment” or to “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one embodiment of the invention, and multiple references to “one embodiment” or “an embodiment” should not be understood as necessarily all referring to the same embodiment. 
     Referring now to  FIG. 1 , an exemplary prior art personal electronic device  100  is shown. Personal electronic device  100  in  FIG. 1  is depicted as a mobile phone, but this is not the only type of device in which the techniques disclosed herein may be implemented. Device  100  is depicted as having display  102 , which may be a capacitive touchscreen interface capable of displaying graphical objects and receiving touch input from a user. Device  100  is also depicted as having a front facing camera  112  and a proximity sensor  114 , which may comprise, e.g., an infrared sensor. Front facing camera  112  may be used to locate a user of device  100  and estimate a distance of the user to the display  102  of device  100 , in addition to the position and direction of gaze of the user&#39;s eyes, as will be explained further below. Proximity sensor  114  may be one of a number of well known proximity sensors known and used in the art, and it may be used, e.g., to detect the presence of nearby objects without any physical contact. As is known in the art, a proximity sensor often emits an electromagnetic or electrostatic field, or a beam of electromagnetic radiation. Front facing camera  112  and proximity sensor  114  may also be used to measure light levels in the environment around the user and to locate light sources in the user&#39;s environment. As described below, such information may be useful in making a realistic virtual 3D depiction of a graphical user interface that appears to be “responsive” to light sources located in the “real world.” In  FIG. 1 , display  102  is shown to be displaying several graphical user interface objects, e.g., icon  104 . Icon  104  may be indicative of a program, file, or other application that the device is capable of executing should the icon be selected by a user. Also shown on display  102  is an object springboard  110 . In the prior art, icons  106  have been depicted as sitting on the surface of springboard  110  to give them the appearance of being in a 3D operating system environment. Additional visual cues may be added to the icons  104 / 106 , such as shines  113  and/or reflections  108  to further enhance the 3D appearance of the icons  104 / 106 . In some embodiments, this enhanced 2D representation may be referred to herein as 2½D. 
     Referring now to  FIG. 2 , an exemplary 3D UI technique that may be employed by a personal electronic device operating in a 2½D operating system environment mode is illustrated, in accordance with one embodiment. In  FIG. 2 , icon  202  is presented in three different virtual lighting environments,  208   a - c . In each environment, shadow layer  200  is repositioned appropriately underneath icon  202  to create the illusion that virtual light source  204  is causing a realistic shadow to be cast by icon  202 . For example, in virtual lighting environment  208   a , virtual lighting source  204   a  is positioned directly over icon  202   a . Thus, shadow layer  200  is placed directly below icon  202   a , i.e., with no offset. This is indicated by coordinate  206   a , representing the lower left corner of shadow layer  200  in virtual lighting environment  208   a . Hypothetical coordinates (x, y) have been assigned to coordinate  206   a  in order to illustrate the repositioning of shadow layer  200  in virtual lighting environments  208   b  and  208   c  as compared to its position in virtual lighting environment  208   a.    
     In virtual lighting environment  208   b , virtual lighting source  204   b  has been positioned above and to the left of icon  202   b . Thus, shadow layer  200  is placed below icon  202   b  and offset slightly to the right. The amount of offset, s, is determined based on the position and distance between the virtual lighting source and the icon, and creates a realistic lighting effect on icon  202   b . The offset, s, is indicated by coordinate  206   b , representing the lower left corner of shadow layer  200  in virtual lighting environment  208   b  and having hypothetical coordinates (x+s, y). 
     In virtual lighting environment  208   c , virtual lighting source  204   c  has been positioned above and to the right of icon  202   c . Thus, shadow layer  200  is placed below icon  202   c  and offset slightly to the left. The amount of offset, s, is determined based on the position and distance between the virtual lighting source and the icon, and creates a realistic lighting effect on icon  202   c . The offset, s, is indicated by coordinate  206   c , representing the lower left corner of shadow layer  200  in virtual lighting environment  208   c  and having hypothetical coordinates (x-s, y). 
     The location of virtual lighting source  204  in a virtual lighting environment used by a personal electronic device employing the techniques disclosed herein may be, e.g., determined programmatically by the device&#39;s operating system, selected manually by the user of the device, or positioned by the device&#39;s operating system to simulate the location of an ambient light source detected in the user&#39;s environment. That is, if a bright light source is located directly above the user of a device, the device&#39;s operating system may place the virtual lighting source directly above the virtual lighting environment, so as to accurately simulate the lighting conditions in the user&#39;s environment. Further, multiple light sources may be detected and simulated in the virtual lighting environment, and the intensities of such detected light sources may also be accurately simulated. 
     The 2½D operating system environment techniques, e.g., the one described above in reference to  FIG. 2 , may be rendered in a relatively computationally cheap and flexible manner by utilizing a suitable graphical programming framework such as Apple Inc.&#39;s CORE ANIMATION® framework. (CORE ANIMATION® is a registered trademark of Apple Inc.) For example, shadow layer  200  is an example of a separate graphical layer that may simply be repositioned at the desired location in the virtual lighting environment to create the illusion that the virtual lighting source has moved. One advantage of the repositioning technique described herein is that the pixels comprising the graphical layer do not need to be re-rendered each time the device&#39;s operating system determines that a repositioning of the graphical layer is necessitated due to e.g., the movement of the device or a change in the lighting conditions in the user&#39;s environment. Another type of graphical layer, known as a “shine map” may also be implemented as a separate graphical layer and can be repositioned over an icon or other graphical user interface object to create the illusion of different virtual lighting scenarios. Again, one advantage to this technique is that the icon or other graphical user interface object content underneath the shine map does not have to be re-rendered each time the device&#39;s operating system determines that a repositioning of the graphical layer is necessitated. 
     Referring now to  FIG. 3 , a personal electronic device  100  presenting a virtual 3D depiction  306  of a graphical user interface object  106  lit by a simulated, i.e., virtual, light source  304  is illustrated, in accordance with one embodiment.  FIG. 3  also shows a side view of virtual 3D operating system environment  300 . The two dimensional icons  104 / 106  depicted in  FIG. 1  have been replaced with virtual 3D representations  105 / 107  of the same icon objects within virtual 3D operating system environment  300 . As shown in  FIG. 3 , icon object is still sitting on springboard  110 . As shown by axes  320 , in  FIG. 3 , the X-axis extends along the width of the display  102  and into the page, the Y-axis extends along the length of display  102 , and the Z-axis extends perpendicularly away from the surface of display  102 . The additional three columns of icons depicted on display  102  in  FIG. 1  are not visible as they would extend along the X-axis into the page in the view presented in  FIG. 3 . It is also to be understood that, in some embodiments, each and every graphical user interface object in the virtual 3D operating system environment  300  would be depicted on display  102  of device  100 . This application focuses only on the representation of a single graphical user interface object, icon  107 , for simplicity and clarity. 
     As is known in the 3D graphics arts, virtual light source  304  may be created by the device&#39;s processor(s) and “placed” at various spots in the virtual 3D operating system environment  300  in order to generate realistic shading and shine effects on objects displayed by device display  102 . As illustrated in  FIG. 3 , light source  304  is placed at the top and center of virtual 3D operating system environment  300 , although such placement is not strictly necessary. Dashed line  318  indicates the path from virtual graphical user interface object  107  to light source  304 . Utilizing the path of dashed line  318  will become important later when certain aspects of ray tracing are discussed in conjunction with rendering a realistic 3D depiction of user interface objects on device display  102 . 
     The eyes of the user of device  100  are represented by element  302  in  FIG. 3 . Dashed line  308  indicates the path from the user&#39;s eyes to the front facing camera  112  of device  100 . As mentioned above, front facing camera  112  may be used to: estimate the length of dashed line  318  (that is, the distance of the user&#39;s eyes to the device); detect (and potentially recognize) the face of the user; measure the current distance between the user&#39;s pupils; or to locate light sources in the user&#39;s environment. Additionally, proximity sensor  114  may be used to further gauge ambient light levels in the user&#39;s environment. Further, light sources in the user&#39;s environment may also be detected by measuring specular reflections off the pupils of the user&#39;s eyes. 
     Vector  310  represents a binormal vector that points perpendicularly out from the display  102 . Vector  312  represents a vector extending from the display  102  directly to the position of the center of user&#39;s eyes  302  along the X-axis. Dashed line  314  is depicted to help illustrate the position of user&#39;s eyes  302  in the direction of the X-axis with respect to the display  102 . The angle  316  between vector  310  and vector  312  can be used by device  100  to determine the angle at which the user is likely viewing display  102 . As illustrated in  FIG. 3 , the user appears to be slightly to the left of the binormal vector  310 , i.e., slightly closer to the “surface” of the page rather than deeper “into” the page. The current position of the user in  FIG. 3  is also reflected in the depiction of graphical user interface object  306  as having a small amount of its left side  307  visible on the device&#39;s display  102  for the user&#39;s current orientation and position shown in  FIG. 3 . As the user&#39;s eyes  302  move farther and farther to the left with respect to the display  102  of device  100 , i.e., as angle  316  increases, the user will be able to see more and more of the left side  307  of graphical user interface object  306 . One way of understanding the 3D effect resulting from the application of such techniques is to envision the display screen  102  of the hand-held device  100  as a “window” into 3D space  300 . As with windows in the real word, as an observer gets closer to or farther from the window, or looks through the window at different angles, the observer is able to see different objects, different angles of objects, etc. To achieve these effects, a technique known as ray tracing may be utilized. 
     Ray tracing, as known in the art, involves simulating the path a photon would take moving from a light source, to an object an observer is viewing, and then reflected to the observer&#39;s eye—only in reverse order. Thus, this process is also sometimes referred to as “backward ray tracing.” In one embodiment of a ray tracing process, for each pixel in display  102 , a ray  304  is extended from the observer&#39;s eye, through the given pixel, and into the virtual 3D operating system environment  300 . Whatever virtual 3D object is “pierced” by the projection of the ray into the virtual 3D environment is then displayed in the corresponding pixel in display  102 . This process results in the creation of a view on the display screen that is the same view an observer would get if he or she was looking through a window into the virtual 3D environment. 
     A further step may be implemented once a virtual 3D object has been “pierced” by the projection of the ray into the virtual 3D environment. Specifically, a second ray  318  may be extended from the virtual 3D object to the position of the virtual lighting source  304 . If another object is pierced by the second ray  318  as it is extended to the light source  304 , it is a cue to the graphics rendering engine to place a shadow on that pixel. In the case of  FIG. 3 , it appears that ray  318  intersects icon objects  105  and  109 , indicating that icon object  107  would have a shadow cast upon its top surface if the user were to adjust his or her own position (or the position of the device) such that he or she could see the top surface of icon object  107 . If no object is detected between the pixel being rendered and the light source, then the relative distance to and intensity of the light source may be used to calculate the brightness intensity of the given pixel as it is displayed on device display  102 . Utilizing these techniques can produce virtual 3D renderings of environments that accurately portray the effects that lighting would have on the virtual 3D objects if they were actually in a real world setting. 
     The techniques described above in relation to  FIG. 3  allow the GPU of the device to apply appropriate lighting and perspective transformations to the virtual 3D depiction of at least one graphical user interface object on the display of the device, thus resulting in a more realistic and immersive virtual 3D experience for the user of the device. 
     Referring now to  FIG. 4 , a personal electronic device  100  presenting a virtual 3D depiction  406  of a graphical user interface object  107  lit by a representative ambient light source  400  is illustrated, in accordance with one embodiment. As in the embodiment described above with respect to  FIG. 3 , ray tracing techniques may be employed by the GPU of device  100  in order to present a realistic virtual 3D depiction of virtual 3D operating system environment  300 . In  FIG. 4 , however, the lighting source for the virtual 3D operating system environment  300  is not a virtual light source created arbitrarily by the operating system of the device; rather, the virtual 3D operating system environment  300  is depicted as though it were being lit by real world ambient light source  400 . Thus, the ray traced back from the virtual 3D operating system environment to ambient light source  400  for object  107  is represented by dashed line  408 . Device  100 &#39;s front facing camera  112  or proximity sensor  114  may be utilized to determine both the distance to (represented by dashed line  402 ) and relative position of the brightest real world ambient light source  400 , as well as the intensity of real world ambient light source  400 . Once this information has been ascertained, the GPU may light the objects in virtual 3D operating system environment  300  according to well known lighting and shading techniques in the 3D graphics arts. 
     As shown in  FIG. 4 , ambient light source  400  is slightly to the right of the device&#39;s display  102 , i.e., slightly farther “into” the page along the X-axis. The current position of the ambient light source  400  in  FIG. 3  is also reflected in the depiction of graphical user interface object  406  as having a small amount of shading  407  on its left side visible on the device&#39;s display  102  for the ambient light source  400 &#39;s current orientation and position as shown in  FIG. 4 . As the ambient light source  400  moves farther and farther to the right with respect to the display  102  of device  100 , i.e., as the ambient light source  400  moves deeper and deeper into the page along the X-axis, there would be more and more shading  404  created on the left sides of the graphical user interface objects  105 / 107  in the virtual 3D operating system environment  300 . Of course, such changes in shading on graphical user interface objects in the virtual 3D operating system environment would likewise be reflected in the rendering of the objects on the device&#39;s display  102  should the device  100  and/or user be positioned and oriented such that a shaded side of a graphical user interface object is visible from the vantage point of the user&#39;s eyes  302 . 
     In addition to using these techniques, the operating system software of the device can determine some light source positions in the user&#39;s environment by analyzing the front-facing camera&#39;s view. Specifically, the device may attempt to locate the brightest areas in the front-facing camera&#39;s view. To avoid falsely identifying specular reflections (e.g., reflections of a pair of eyeglasses) as light sources, the image received from the front-facing camera may be blurred using a small radius, such as with a Gaussian blur at a standard deviation of 3.0, thus reducing the salience of small specular reflections. In one embodiment, the brightest 5% of the image, if brighter than a predetermined brightness value, may be recognized as a light source and located by thresholding the image, a technique which is known in the image processing art. Once thresholded, the shape i.e., the alpha mask, as well as the centroid of the light source may be computed. The computed centroid may be used to determine the light source&#39;s bearing direction in real-world 3D space. Further, a luminance-thresholded version of the front-facing camera&#39;s image may be used to put realistic reflections on the renderings of curved objects in the virtual 3D operating system environment. Additionally, if there are no sufficiently bright ambient lights sources located in the environment of the user, the process may default to using a virtual light source, as in  FIG. 3  above. 
     It is also possible, for usage of a device outdoors, to compute the position of the Sun as a real-world light source in the user&#39;s environment. This can be done by using Greenwich Mean Time (GMT), the GPS location of the device, and compass bearings, as well as the Frenet frame of the device in the local geographic coordinate system. The technique for the computation of the Sun&#39;s relative position at a known point on the earth is well-known. Once computed, the location of the Sun may be utilized to generate a virtual light source for the virtual 3D operating system environment that is representative of the Sun&#39;s current location. 
     Referring now to  FIG. 5 , the Frenet frame  500  for a personal electronic device  100  is illustrated, in accordance with one embodiment. As discussed above, in mathematics, a Frenet Frame is defined by the tangent, normal, and binormal unit vectors for a particle moving along a continuous, differentiable curve in three dimensional space, which are often called T, N, and B vectors, as shown in  FIG. 5 . The T is the unit vector tangent to the curve, pointing in the direction of motion; N is the derivative of T with respect to the arclength parameter of the curve, divided by its length; and B is the cross product of T and N. As shown in  FIG. 5 , T is aligned with the Y axis of the display, N is aligned with the X axis of the display, and B is normal to the plane of the display. Together, the T, N, and B vectors of the Frenet frame tie the display coordinate system to the coordinate system of the real world. 
     By utilizing the various positional sensors in device  100 , such as a compass, a Micro-Electro-Mechanical Systems (MEMS) accelerometer, a GPS module, and a MEMS gyrometer, a 3D frame of reference may be inferred for the device  100 . In fact, it is now possible to track the Frenet frame of the device in real time, thus providing a continuous 3D frame of reference for the hand-held device. Once the continuous frame of reference of the device is known, in addition to the position of the user&#39;s eyes, more realistic virtual 3D depictions of the objects on the device&#39;s display may be created and interacted with, as is explained further with respect to  FIG. 6  below. 
     Referring now to  FIG. 6 , the effects of device movement  600  on a personal electronic device  100  presenting a virtual 3D depiction  606  of a graphical user interface object  107  is illustrated, in accordance with one embodiment. Notice that the Frenet frame  608  of the device  100  as oriented in  FIG. 6  is substantially different from the Frenet frame  500  of the device  100  as oriented in  FIG. 5 . Specifically, the device  100  has been tilted such that the eyes  302  of the user look slightly downwards into virtual 3D operating system environment  602 . Arrow  600  is indicative of the difference in position of device  100  between  FIG. 5  and  FIG. 6 . As can be seen from the projection ray traces  604  extending from the eyes  302  of the user through the plane of the device display  102  and into the virtual 3D operating system environment  602 , the depiction  607  of graphical user interface object  107  shows a small amount of graphical user interface object  107 &#39;s top surface  607  on the device&#39;s display  102 . This is in contrast to the depiction  406  of graphical user interface object  107  shown in  FIG. 4 , wherein the “window” into the virtual 3D operating system environment  300  (i.e., the “window” being the display  102  of device  100 ) is more parallel with respect to the orientation of the vertical stacks of icon objects in the virtual 3D operating system environment, and, thus, the user is unable to see the top surface of graphical user interface object  107 . Applying these techniques, it becomes clear that the user would be able to manipulate the position of the device and/or his or her eyes in order to see the side surfaces of graphical user interface objects or even behind graphical user interface objects. 
     Referring now to  FIG. 7 , the effects of user movement on a personal electronic device  100  presenting a virtual 3D depiction  700  of a graphical user interface object  107  is illustrated, in accordance with one embodiment. As in  FIG. 3 , dashed line  712  indicates the path from the user&#39;s eyes to the front facing camera  112  of device  100 . As mentioned above, front facing camera  112  may be used to: estimate the length of dashed line  712  (that is, the distance of the user&#39;s eyes to the device); detect (and potentially recognize) the face of the user; measure the current distance between the user&#39;s pupils; or to locate light sources in the user&#39;s environment. Vector  706  represents a binormal vector that points perpendicularly out from the display  102 . Vector  708  represents a vector extending from the display  102  directly to the position of the center of user&#39;s eyes  702  along the X-axis. Dashed line  710  is depicted to help illustrate the position of user&#39;s eyes  602  in the direction of the X-axis with respect to the display  102 . The angle  704  between vector  706  and vector  708  can be used by device  100  to determine the angle at which the user is likely viewing display  102 . As illustrated in  FIG. 7 , the user appears to be slightly to the left of the binormal vector  706 , i.e., slightly closer to the “surface” of the page rather than deeper “into” the page. 
     Compared to  FIG. 3 , the eyes  702  of the user in  FIG. 7  are much farther away from the display  102  of device  100 . As such, the ray tracing and projection (as represented by dashed lines  714 ) of graphical user interface object  107  onto the display  102  places depiction  700  of graphical user interface object  107  at a lower position on the display  102  in  FIG. 7  than the depiction  206  of graphical user interface object  107  in  FIG. 3 . This is consistent with producing the effect of the user looking through a “window” into the virtual 3D operating system environment  300 . Continuously monitoring the position of device  100  in addition to the position of the eyes  702  of the user can provide for a compelling and realistic virtual experience. It should be noted, however, that monitoring the device&#39;s Frenet frame changes over time alone (i.e., not in conjunction with the position of the user) often provides sufficient information for the device&#39;s operating system software to create realistic 3D UI effects. Creating 3D UI effects without knowing the exact position of the user is possible by assuming a typical user&#39;s position with respect to the device. For example, it is recognized that, ergonomically, there are a small number of positions that are useful for viewing a personal electronic device&#39;s display. Small devices are generally held closer to the user&#39;s eyes, and larger devices are generally held farther away from the user&#39;s eyes. Additionally, the user&#39;s gaze is generally focused centrally on the display surface of the device. 
     Referring now to  FIG. 8 , a recessed, “bento box” form factor inside the virtual 3D environment  812  of a personal electronic device  100  is illustrated, in accordance with one embodiment. As the user moves the device  100  around, the shadows  814  depicted on the display  102  could move as well, thus increasing the 3D effect perceived by the user. Various other 3D effects could also be employed to increase the 3D effect perceived by the user. For example, if the objects  802  inside the virtual 3D environment  812  are rounded, then shines  816  reflecting off the objects could also change correspondingly. If the objects  802  are diffuse, then their shading could change with device  100 &#39;s movement. 
     The recessed, “bento box” form factor inside the virtual 3D environment  812  of a personal electronic device  100  may also be constructed with individual interface objects  802  inside each of a group of sub-boxes  800 . As shown in  FIG. 8 , there are three sub-boxes  800   a / 800   b / 800   c . Each sub-box  800  may have a set of side walls  818  that form the borders of the recessed sub-box  800 . As a user reorients device  100  to “look inside” each sub-box  800 , a “spotlight” illustrated by dashed lines  804  and dashed circle  806  can highlight the sub-box into which the user&#39;s view is currently directed. In some embodiments, a decision as to whether the user is looking into a particular sub-box may be based on, for example, the fact that all walls  818  of that sub-box  800  are forward-facing to the user, and thus visible. 
     As illustrated in  FIG. 8 , the user  808   a  is hovering above device  100  and looking down into the display  102  of the device  100 , as represented by sightline  810   a  and the fact that no side surfaces of the graphical user interface objects  802 / 803 / 805 / 807  are visible on the currently rendered display  102 . For user  808   a , the spotlight effect  804 / 806  is applied to the display  102  in the area of sub-box  800   a  and serves to highlight the representations of graphical user interface objects  802  and  803 . A spotlight  806  may be considered to be a concentrated virtual light source that is directed at a particular graphical user interface object(s) or area, e.g., sub-box  800   a  in  FIG. 8 , in the virtual 3D operating system environment. In the graphics arts, displayed object color may be computed by multiplying the light source&#39;s color and intensity by the display object&#39;s color. A spotlight may be represented as a light source where the light intensity falls off as a function of distance or angular displacement from the center light vector, which may be calculated by subtracting the light source&#39;s position from the location where the light is pointed. This function may be, e.g., a function characterized by having an exponential falloff. 
     Users  808   b  and  808   c  represent alternate positions from which a user could attempt to view the virtual 3D environment  812 . From the perspective of user  808   b  looking along sightline  810   b , all walls  818  of sub-box  800   b  would be forward-facing to the user  808   b , and thus the spotlight effect  804 / 806  would be applied to the display  102  in the area of sub-box  800   b  and serve to highlight the representations of graphical user interface object  805 . From the perspective of user  808   c  looking along sightline  810   c , all walls  818  of sub-box  800   c  would be forward-facing to the user  808   c , and thus the spotlight effect  804 / 806  would be applied to the display  102  in the area of sub-box  800   c  and serve to highlight the representations of graphical user interface object  807 . It is understood that other variants to the recessed, “bento box” form factor fall within the scope of the teachings of this disclosure and could likewise be implemented to take advantage of continuously tracking a 3D frame of reference of the device and/or the position of the user&#39;s eyes to create a more realistic virtual 3D experience for the user. 
     Referring now to  FIG. 9 , a point of contact  902  with the touchscreen display  102  of a personal electronic device  101  that is ray traced  904  into a virtual 3D operating system environment  300  is illustrated, in accordance with one embodiment. By ray tracing the location of the touch point of contact  902  on the device&#39;s display  102  into the virtual 3D operating system environment  300  (as described above in reference to  FIG. 3 ) and intersecting the region of the touch point in the virtual 3D environment  906  with whatever object or objects it hits, the user can perceive that he or she is interacting with a 3D environment via a 2D touchscreen interface, providing a richer and more realistic user experience. As illustrated in  FIG. 9 , the location in which the user  900  has touched the touchscreen display  102  corresponds to touch point  906  in virtual 3D environment  300  and intersects with graphical user interface object  107 . Thus, a touch by user  900  creating point of contact  902  could result in applying a motion or effect to object  107  in the virtual 3D operating system environment  300  that would cause object  107  in the virtual 3D operating system environment  300  to behave similarly to how it would behave if the device was operating in a traditional “2D” mode. For example, the techniques disclosed herein would make it possible to simulate resizing, depressing, toggling, dragging, pushing, pulling, collision effects, and other physical manifestations of reality within the virtual 3D operating system environment  300  in a more compelling and realistic manner. In the case of simulating a “depress” 3D UI effect, e.g., the depressing of a graphical user interface object such as a button or icon  107 , the effect may be implemented in response to the detected position  902  of the user&#39;s finger  900 . This can be done because, once the touch location  902  of the user&#39;s finger  900  is located in the virtual 3D environment  300 , e.g., represented by dashed circle  906  in  FIG. 9 , it may be found that the touch location intersects the plane of some graphical user interface object, e.g., the front plane of icon  107 , and any touch movement may be translated into that plane or interpreted in the context of that particular graphical user interface object&#39;s potential degrees of freedom of movement. For example, some objects may only be able to be “depressed” inwardly, whereas others may be free to move in any number of directions. 
     In another embodiment, a shadow or other indicator  902  of the user  900 &#39;s finger tip may be displayed in the appropriate place in the 2D rendering of the virtual 3D operating system environment  300  depicted on display  102 . Information about the position of the user  900 &#39;s fingertip can be obtained from contact information reported from the touchscreen or from near-field sensing techniques, each of which is known in the art. In this way, the user of device  100  can actually feel like he or she is “reaching into” the virtual 3D environment  300 . Using near-field sensing techniques, a finger&#39;s position in the “real world” may be translated into the finger&#39;s position in the virtual 3D operating system environment by reinterpreting the distance of the finger from the device&#39;s display as a distance of the finger from the relevant graphical user interface object in the virtual 3D operating system environment, even when the relevant graphical user interface object is at some “distance” into the virtual 3D world within the display&#39;s “window.” For example, utilizing the techniques disclosed herein, if a user&#39;s finger were sensed to be one centimeter from display  102 , the relevant indication of the location of the user&#39;s touch point in the virtual 3D operating system environment, e.g., dashed circle  906  in  FIG. 9 , may cast a shadow or display some other visual indicator “in front of” the relevant graphical user interface object, thus providing an indication to the user that they are not yet interacting with the relevant graphical user interface object, but if the user were to move their finger closer to the display&#39;s “window,” i.e., touch surface display  102 , they may be able to interact with the desired graphical user interface object. The use of a visual indicator of the user&#39;s desired touch location, e.g., the “shadow offset,” is not only an enhanced 3D UI effect. Rather, because knowledge of the 3D frame of reference of the device allows for better accounting of touchscreen parallax problems, i.e., the misregistration between the touch point and the intended touch location being displayed, the techniques described herein with respect to  FIG. 9  may also provide the user of the device with a better representation of what interactions he or she would be experiencing if the graphical user interface objects were “real life” objects. 
     Referring now to  FIG. 10 , an exemplary gesture  1002  for activating the display  102  of a personal electronic device  100  to operate in a virtual 3D operating system environment mode is illustrated, in accordance with one embodiment. As mentioned above, constantly using the device&#39;s GPU for rendering 3D information or ray tracing is computationally expensive and can be a battery drain. In some embodiments, the device will operate in 2D or 2½D mode by default. Thus, a gesture can be used to “unfreeze” the 2D or 2½D display to operate in 3D mode. One potential “activation gesture” is the so-called “princess wave,” i.e., the wave-motion rotation of the device about its Y-axis  1000 . For example, the virtual 3D operating system environment mode can be turned on when more than three waves of 10-20 degrees  1002  of modulation along one axis  1000  occur within a predetermined threshold amount of time, e.g., one second. Position quiescence, e.g., holding the device relatively still for at least a predetermined threshold amount of time, e.g., two to three seconds, could be one potential cue to the device  100  to freeze back to the 2D or 2½D operating system environment mode and restore the display of objects to their traditional 2D representations. In this way, it is unlikely that the device  100  could be put into 3D mode without explicit control and intent from the user. It is also likely that the device would return to the computationally cheaper 2D or 2½D mode automatically, if left alone for a sufficient amount of time. 
     In one embodiment, when the appropriate activating gesture  1002  for activating the display  102  of a personal electronic device is detected and the virtual 3D operating system environment mode turns on, each of the graphical user interface objects on the display of the device may “unfreeze” and turns into a 3D depiction of the object, e.g., a depiction that is nearly identical to the 2D depiction of the object, along with shading, shine reflections  1012 , and/or textures indicative of 3D object appearance. For example, each of the icons  1006  on a springboard  110 , such as is shown on the display  102  of the device  100  in  FIG. 10 , could transform from 2D representations of icons into 3D “Lucite” cubes  1004 / 1006 , i.e., cubes that appear to be made of a clear plastic or glass-like material and that have pictures at the bottom of them. (LUCITE® is a registered trademark of Lucite International, Inc.) When the icons are unfrozen into the 3D mode, the pictures at the bottoms of the icon cubes  1004 / 1006  could refract and distort appropriately, providing a visually distinct impression. It is also possible for the cubes to be slightly rounded on their front surfaces. This can be done both to magnify the icons below them and also to catch reflected “light” off their surfaces when the display is reoriented with respect to the user&#39;s gaze. 
     Referring now to  FIG. 11 , one embodiment of a process for operating a personal electronic device in a virtual 3D operating system environment mode is illustrated in flowchart form. First, the process begins at Step  1100 . Next, one or more processors or other programmable control devices within the personal electronic device defines a virtual 3D operating system environment (Step  1102 ). Next, the processor(s) may receive data from one or more position sensors disposed within a hand-held device (Step  1104 ). The processor(s) may then determine a 3D frame of reference for the device based on the received position data (Step  1106 ). Next, the processor(s) may receive data from one or more optical sensors, e.g., an image sensor, a proximity sensor, or a video camera disposed within a hand-held device (Step  1108 ). The processor(s) may then determine a position of a user of the device&#39;s eyes based on the received optical data (Step  1110 ). In another embodiment, Step  1110  may be omitted, and a fixed, assumed position for the user may be used by the processor(s). For example, it is recognized that, ergonomically, there are a small number of positions that are useful for viewing a personal electronic device&#39;s display. Small devices are generally held closer to the user&#39;s eyes, and larger devices are generally held farther away from the user&#39;s eyes. Additionally, the user&#39;s gaze is generally focused centrally on the display surface of the device. Finally, the processor(s) may then project, i.e., render, a visual representation of the virtual 3D operating system environment onto a graphical user interface display of the device based on the determined 3D frame of reference and the determined position of the user of the device&#39;s eyes (Step  1112 ). As discussed in detail above, this process can provide for a distinct and more realistic presentation of a virtual 3D operating system environment onto the display of a user device, e.g., a hand-held, personal electronic device such as a mobile phone. 
     Referring now to  FIG. 12 , one embodiment of a process for toggling a personal electronic device between operating in a virtual 3D operating system environment mode and a non-virtual 3D operating system environment mode, e.g., a 2D mode, is illustrated in flowchart form. First, the process begins at Step  1200 . Next, one or more processors or other programmable control devices within the personal electronic device may display a 2D representation of an operating system environment on a graphical user interface display of a device (Step  1202 ). Then, the processor(s) detects whether it has received a gesture at the device indicative of a desire of the user to enter into a virtual 3D display mode, e.g., a one-axis sine wave modulation of the device of a sufficient number of degrees and within a sufficiently short amount of time (Step  1204 ). If it has not received such a gesture, the process returns to Step  1202  and continues to display a 2D representation of the operating system environment. If, instead, the processor(s) has received such a gesture, the process proceeds to Step  1206 , which indicates to the processor(s) to perform the process described in  FIG. 11 , i.e., a process for operating the personal electronic device in a virtual 3D operating system environment mode. While operating in the virtual 3D operating system environment mode, the processor(s) continues to “listen” for gestures at the device indicative of a desire of the user to return to a 2D display mode, e.g., quiescence (less than some threshold of motion for a threshold amount of time (Step  1208 ). If it has not received such a gesture, the process returns to Step  1206  and continues to display a virtual 3D representation of the operating system environment according to the process described in  FIG. 11 . If, instead, the processor(s) detects that it has received such a gesture indicative of a desire of the user to return to a 2D display mode, the process returns to Step  1202 , i.e., a process for operating the personal electronic device in a 2D display mode. 
     Referring now to  FIG. 13 , one embodiment of a process for projecting spotlights indicative of the position of a user&#39;s eyes into a virtual 3D operating system environment of a personal electronic device is illustrated in flowchart form. First, the process begins at Step  1300 . Next, one or more processors or other programmable control devices within the personal electronic device defines a virtual 3D operating system environment (Step  1302 ). Next, the processor(s) may project, i.e., render, a visual representation of the virtual 3D operating system environment onto a graphical user interface display of the device (Step  1304 ). Next, the processor(s) may receive data from one or more optical sensors, e.g., an image sensor, a proximity sensor, or a video camera, disposed within a hand-held device (Step  1306 ). The processor(s) may then determine a position of a user of the device&#39;s eyes based on the received optical data (Step  1308 ). Finally, the processor(s) may then project, i.e., render, a visual representation of “spotlights” into the virtual 3D operating system environment based on the determined position of the user of the device&#39;s eyes (Step  1310 ), at which the point the process may return to Step  1306 , wherein the processor(s) may receive continuous data from the one or more optical sensors disposed within the hand-held device to allow the device&#39;s display to be updated accordingly as the user&#39;s eyes continue to move to and focus on different areas of the display. 
     Referring now to  FIG. 14 , one embodiment of a process for implementing graphical user interface effects on the display of a personal electronic device based on ambient light sources detected in the environment of the device and/or the relative position of the device is illustrated in flowchart form. First, the process begins at Step  1400 . Next, one or more processors or other programmable control devices within the personal electronic device defines a virtual “2½D” operating system environment for a device, that is, an enhanced 2D representation of an operating system environment possessing certain additional visual cues on icons, toolbars, windows, etc., such as shading and/or reflections, which additional cues are used to further heighten the “3D appearance” of the 2D icons. In some embodiments, the techniques described with respect to  FIG. 14  may also be applied to a virtual 3D operating system environment (Step  1402 ). Next, the processor(s) may project, i.e., render, a visual representation of the virtual 2½D operating system environment onto a graphical user interface display of the device (Step  1404 ). Next, the processor(s) may receive data from one or more optical sensors, e.g., an image sensor, a proximity sensor, or a video camera, disposed within a hand-held device (Step  1406 ). The processor(s) may then determine a position of one or more ambient light sources based on the received optical data (Step  1408 ). Next, the processor(s) may receive data from one or more position sensors disposed within a hand-held device (Step  1410 ). The processor(s) may then determine a 3D frame of reference for the device based on the received position data (Step  1412 ). Finally, the processor(s) may apply UI effects (e.g., shine, shading) to objects in the virtual 2½D operating system environment based on the determined position of the ambient light sources and/or the determined 3D frame of reference for the device (Step  1414 ). As discussed above in reference to  FIG. 2 , various graphical layers, such as shadows and shine maps may be continuously and dynamically re-positioned without being re-rendered based on the position of the device and/or the location of an ambient light source. Further, adjustments of scale and position can also be made to various graphical user interface objects in order to make the display appear to be even more “3D-like” than it already appears. 
     Referring now to  FIG. 15 , a simplified functional block diagram of a representative personal electronic device  1500  according to an illustrative embodiment, e.g., a mobile phone possessing a camera device such as front facing camera  112 , is shown. The personal electronic device  1500  may include a processor(s)  1516 , storage device  1514 , user interface  1518 , display  1520 , coder/decoder (CODEC)  1502 , bus  1522 , memory  1512 , communications circuitry  1510 , a speaker or transducer  1504 , a microphone  1506 , position sensors  1524 , proximity sensor  1526 , and an image sensor with associated camera hardware  1508 . Processor  1516  may be any suitable programmable control device, including a GPU, and may control the operation of many functions, such as the 3D user interface effects discussed above, as well as other functions performed by personal electronic device  1500 . Processor  1516  may drive display  1520  and may receive user inputs from the user interface  1518 . In some embodiments, device  1500  may possess one or more processors for performing different processing duties. 
     Storage device  1514  may store media (e.g., photo and video files), software (e.g., for implementing various functions on device  1500 ), preference information (e.g., media playback preferences), personal information, and any other suitable data. Storage device  1514  may include one more storage mediums, including for example, a hard-drive, permanent memory such as ROM, semi-permanent memory such as RAM, or cache. 
     Memory  1512  may include one or more different types of memory which may be used for performing device functions. For example, memory  1512  may include cache, ROM, and/or RAM. Bus  1522  may provide a data transfer path for transferring data to, from, or between at least storage device  1514 , memory  1512 , and processor  1516 . CODEC  1502  may be included to convert digital audio signals into analog signals for driving the speaker  1504  to produce sound including voice, music, and other like audio. The CODEC  1502  may also convert audio inputs from the microphone  1506  into digital audio signals for storage in memory  1512  or storage device  1514 . The CODEC  1502  may include a video CODEC for processing digital and/or analog video signals. 
     User interface  1518  may allow a user to interact with the personal electronic device  1500 . For example, the user input device  1518  can take a variety of forms, such as a button, keypad, dial, a click wheel, or a touchscreen. Communications circuitry  1510  may include circuitry for wireless communication (e.g., short-range and/or long range communication). For example, the wireless communication circuitry may be Wi-Fi® enabling circuitry that permits wireless communication according to one of the 802.11 standards. (Wi-Fi® is a registered trademark of the Wi-Fi Alliance.) Other wireless network protocols standards could also be used, either as an alternative to the identified protocols or in addition to the identified protocols. Other network standards may include BLUETOOTH®, the Global System for Mobile Communications (GSM®), and code division multiple access (CDMA) based wireless protocols. (BLUETOOTH® is a registered trademark of Bluetooth SIG, Inc., and GSM® is a registered trademark of GSM Association.) Communications circuitry  1510  may also include circuitry that enables device  1500  to be electrically coupled to another device (e.g., a computer or an accessory device) and communicate with that other device. 
     In one embodiment, the personal electronic device  1500  may be a personal electronic device capable of processing and displaying media such as audio and video. For example, the personal electronic device  1500  may be a media device such as media player, e.g., a mobile phone, an MP3 player, a game player, a remote controller, a portable communication device, a remote ordering interface, an audio tour player, or other suitable personal device. The personal electronic device  1500  may be battery-operated and highly portable so as to allow a user to listen to music, play games or video, record video, stream video, take pictures, communicate with others, interact with a virtual operating system environment, and/or control other devices. In addition, the personal electronic device  1500  may be sized such that it fits relatively easily into a pocket or hand of the user. By being hand-held, the personal computing device  1500  may be relatively small and easily handled and utilized by its user and thus may be taken practically anywhere the user travels. 
     As discussed previously, the relatively small form factor of certain types of personal electronic devices  1500 , e.g., personal media devices, enables a user to easily manipulate the device&#39;s position, orientation, and movement. Accordingly, the personal electronic device  1500  may provide for improved techniques of sensing such changes in position, orientation, and movement to enable a user to interface with or control the device  1500  by affecting such changes. For example, position sensors  1524  may comprise compasses, accelerometers, gyrometers, or GPS units. Further, the device  1500  may include a vibration source, under the control of processor  1516 , for example, to facilitate sending motion, vibration, and/or movement information to a user related to an operation of the device  1500 . The personal electronic device  1500  may include an image sensor and associated camera hardware  1508  that enables the device  1500  to capture an image or series of images, i.e., video, continuously, periodically, at select times, and/or under select conditions. The personal electronic device  1500  may also include proximity sensors  1526  that enable the device  1500  to characterize and identify light sources in the real world environment surrounding the device  1500  and make determinations of whether, e.g., a user or the finger of a user is in close proximity to the display  1520  of device  1500 . 
     The foregoing description is not intended to limit or restrict the scope or applicability of the inventive concepts conceived of by the Applicants. As one example, although the present disclosure focused on 3D user interface effects for a virtual operating system environment; it will be appreciated that the teachings of the present disclosure can be applied to other contexts, e.g.: digital photography, digital videography, television, video gaming, biometrics, or surveillance. In exchange for disclosing the inventive concepts contained herein, the Applicants desire all patent rights afforded by the appended claims. Therefore, it is intended that the appended claims include all modifications and alterations to the full extent that they come within the scope of the following claims or the equivalents thereof.