Abstract: Collision detection is a vital task in almost all forms of computer animation and physical simulation. It is also one of the most computationally expensive, and therefore a frequent impediment to efficient implementation of real-time graphics applications. We describe how graphics hardware can be used as a geometric co-processor to carry out the bulk of the computation involved with collision detection. Hardware frame buffer operations are used to implement a ray-casting algorithm which detects static interference between solid polyhedral objects. The algorithm is linear in both the number of objects and number of polygons in the models. It also requires no preprocessing or special data structures.