Real time accurate collision detection for virtual characters

This paper presents an accurate real time collision detection algorithm for interactively animated virtual characters using sphere-trees as Bounding Volume Hierarchies. We build upon a fast mathematical method for on-demand sphere refitting during the animation and improve it for being applicable to any object, without dependency on its geometrical level of detail or its dynamic/static behavior. It uses sphere-plane intersection test as the exact test in the collision detection algorithm instead of the usual triangle-triangle one. Corner-trees, a special hierarchy that ensures the utilization of the plane-sphere intersection test is right, are also presented. In the worst case, the optimization decreases in 25% the time needed to process a frame in extreme conditions. The algorithm has been successfully tested on a real time and collaborative 3D virtual world