A collision model for rigid and deformable bodies

We describe models and algorithms designed to produce efficient and physically consistent dynamic simulations. These models and algorithms have been implemented in a unique framework, modeling both deformations and contacts through visco-elastic relations. Since this model of interaction (known as "penalty based") is much debated, we present it in detail. The "penalty" based model is said to have two major drawbacks: the difficulty in determining viscoelastic parameters, and in choosing the computation time step. We present a solution for both problems based on physical concepts. Finally, we show results comparing real data, "impulse" based simulation and "penalty" based simulation.