Derivation of contact states from geometric models of objects

An efficient algorithm is presented to identify the topological contacts between two contacting polytopes from their geometric models. The algorithm extends the result of the polytope distance algorithm by Gilbert et. al (1988) by exploring local topological information. Its worst-case time complexity is O(N+n_ev/²), where N is the total number of vertices of two contacting polytopes and n_e v/ is the average number of edges at one vertex. The algorithm is fully implemented and used in a computer simulation system for a contact-based fine motion planning scheme. With its great efficiency and effectiveness, the algorithm can be used in any computer modeling and simulation environment which require reasoning about topological contacts