A randomized algorithm to make virtual contact and friction forces by experimental calibration

We propose a randomized algorithm to make contact and friction force models which are used in a 3D graphics animation. We first retrieve a small set of regions where a dynamic object and static objects exist. This is done via an octree representation with a 3D hierarchical structure in positioning. By the synchronous binary search on the X, Y, and Z axes under the structure, the octree-based algorithm efficiently selects the set. Next, using translation of a dynamic object, we detect an initial contact from the set. Based on the contact point, we calculate the base contact and friction force vectors. Then, we calibrate an exact set of contact and friction force vectors by a randomized algorithm using many experimental results. By composing a sequence of best-first motions and that of random motions, the randomized algorithm can build approximated models of contact and friction forces and consequently can generate a impulse force with high quality.