US Patent 8970625 Three-dimensional tracking of a user control device in a volume

Tracking objects presented within a stereo three-dimensional (3D) scene. The user control device may include one or more visually indicated points for at least one tracking sensor to track. The user control device may also include other position determining devices, for example, an accelerometer and/or gyroscope. Precise 3D coordinates of the stylus may be determined based on location information from the tracking sensor(s) and additional information from the other position determining devices. A stereo 3D scene may be updated to reflect the determined coordinates.