Interactive collision detection

Collision detection and response can make a virtual-reality application seem more believable. Unfortunately, existing collision-detection algorithms are too slow for interactive use. The authors present a new algorithm that is not only fast but also interruptible, allowing an application to trade quality for more speed. The algorithm uses simple four-dimensional geometry to approximate motion, and sets of spheres to approximate three-dimensional surfaces. The algorithm allows a sample application to run five to seven times faster than it runs with existing algorithms.>