A practical vision based approach to unencumbered direct spatial manipulation in virtual worlds

We present a practical approach for developing interactive environments that allows humans to interact with large complex 3D models without them having to manually operate input devices. The system provides support for scene manipulation based on hand tracking and gesture recognition and for direct 3D interaction with the 3D models in the display space if a suitably registered 3D display is used. Being based on markerless tracking of a user's two hands, the system does not require users to wear any input or output devices. 6DOF input is provided by using both hands simultaneously,making the tracker more robust since only tracking of position information is required. The effectiveness of the method is demonstrated with a simple application for model manipulation on a large stereo display, in which rendering constraints are met by employing state-of-the-art multiresolution techniques.