Off-line Model Simplification for Interactive Rigid Body Dynamics Simulations

Rigid body dynamics simulations require use of accurate computation of contacts among bodies. Often collision detection algorithms are used for determining the contact between moving bodies. Mechanical parts have a large number of features and hence collision detection with the detailed part models often slows down the rigid body dynamics simulations. In many simulation scenarios, all the parts participating in the simulation are known in advance. In such cases, the simulation context (i.e., a priori knowledge of parts) can be exploited to simplify the part geometries such that the contact points among parts do not change. For example, parts with significant concavities may have regions on their boundaries that will be inaccessible to other parts in the simulation and hence contact points cannot lie on such inaccessible regions. Removing such regions from the parts can simplify the model and hence speed up the simulation. In this paper, we describe an off-line simplification algorithm that performs part simplification based on accessibility considerations. Our algorithm ensures that the potential contact points among parts do not change as a result of the simplification process and hence it preserves the underlying physics.