Efficient frictional contacts for soft body dynamics via ADMM

Siyan Zhu, Cheng Fang, Peng Yu, Xiao Zhai, Aimin Hao, Junjun Pan

Abstract: This paper addresses the longstanding challenge of soft body dynamics with frictional contact through a novel combination of Projective Dynamics for elasticity simulation and Alternating Direction Method of Multipliers for frictional contact handling. The approach utilizes parallel local strain projection for deformable bodies and nonlinear Projected Gauss-Seidel for contact with Coulomb friction, consolidated by a pre-factorized global strain propagation step. Integration of contact stabilization, Matchstick anisotropic friction, and Rayleigh damping enhances reliability and usability. Effectiveness, accuracy, and computational efficiency are demonstrated in challenging cases, including multi-layer and persistent contacts. With a CPU-based parallel implementation, our method achieves visually plausible and stable simulation results at an interactive framerate in moderate-scale scenes, showcasing its applicability across various graphics applications.