PQP was adapted from RAPID2, and the API should be familiar to RAPID2 users.
In addition, collision detection techniques have been borrowed from RAPID2, including the tree building strategies and the use of oriented bounding boxes (OBBs). However, this package uses a different bounding volume type, the rectangle swept sphere (RSS), for distance and tolerance queries.
As with RAPID, the models used with PQP do not need to contain adjacency information, or obey topological constraints. The models may contain cracks, holes, self-intersections, and nongeneric (e.g. coplanar and collinear) configurations.