Nonlinear Interactive Motion Control Techniques for Virtual Space Navigation

For virtual reality scienti c visualization applications, the traditional navigational analogue of moving in a room (the \emersion" technique) is not adequate. Moving out of the simulation box and getting a panoramic view of the visualization is essential. In this way the sense of emersion is augmented by the ability of overviewing. Visualization applications also require that interactions in a global scale are possible at any time. We present in this paper non-linear motion control techniques that allow fast and intuitive control of the viewpoints as well as the hand positions within a virtual workspace. They allow the users to quickly move in and out of the simulation box, and at the same time interact with the simulation with the hand device no matter where the viewpoint is located. The principle is to divide the working range of a physical input device into several parts and use di erent mapping functions to map the parameters of the device into virtual space. Providing a consistent cognitive model and maintaining smooth transitions between subspaces are the basic requirements for this type of techniques. Our proposed techniques are natural to users