Exact collision detection of scaled convex polyhedral objects with inner ellipsoidal bounds

For collision detection between identically scaled convex polyhedral objects (i.e. objects deformed with shape unchanged but size changed), we have presented an accuracy-tunable collision detector based on inner-outer ellipsoidal deformation bounds (S. Liu et al., 2005). This paper explores further the possibility of exact collision detection based only on approximate closest points, in which a special design of exact collision detector tailored to identically scaled convex polyhedral objects is detailed. The collision detector is parametric distance difference in the direction of shortest path between inner ellipsoids, which measures how far the current configuration from the configuration of objects assumed touching each other externally without overlapping