they decided to track the location of the glasses in the depth image instead of tracking the eyes. They used that information to compute the user’s viewpoint. This camera tracks the user's eyes and performs a real time capturing of both shape and appearance of any object placed in front of the camera. The system enables perspective stereoscopic 3D visualization to a single user. Figure 4 shows the experimental results. This allows the user to interact with virtual objects through freehand actions without handling.