Loosely-constrained volumetric contact force computation for rigid body simulation

A novel method to compute the contact force in forward dynamics simulation of rigid bodies based on contact volume is proposed. The conventional methods are based on contact vertices, where the normal and tangential directions are estimated with respect to each pair of facets or facet and vertex of colliding bodies. However, the normal direction is intrinsically determined based on the solid deformation. This paper proposes a novel method that combines the constraint-based method and the volumetric intersection computation. Since the method estimates a 6-axis resultant force directly, there are two problems that are how to predict the preferred deformation of the volume and how to confirm the friction limit. The idea is to apply the least-square method for the former and to check if the computed force can be resolved into each stress within the friction limit. The proposed method checks the condition with linear programming method through a pyramidal approximation.