Simulating Articulated Subspace Self-Contact
Proceedings of ACM SIGGRAPH 2014

Above: A hand mesh composed of 458K tetrahedra, running at 5.8 FPS (171 ms), including both self-contact detection and resolution. Our algorithm accelerates the computation of complex self-contacts by a factor of 5x to 52x over other subspace methods and 166x to 391x over full-rank simulations. Our self-contact computation never dominates the total time, and takes up at most 46% of a single frame.

We present an efficient new subspace method for simulating the self-contact of articulated deformable bodies, such as characters. Self-contact is highly structured in this setting, as the limited space of possible articulations produces a predictable set of coherent collisions. Subspace methods can leverage this coherence, and have been used in the past to accelerate the collision detection stage of contact simulation. We show that these methods can be used to accelerate the entire contact computation, and allow self-contact to be resolved without looking at all of the contact points. Our analysis of the problem yields a broader insight into the types of non-linearities that subspace methods can efficiently approximate, and leads us to design a pose-space cubature scheme. Our algorithm accelerates self-contact by up to an order of magnitude over other subspace simulations, and accelerates the overall simulation by two orders of magnitude over full-rank simulations. We demonstrate the simulation of high resolution (100K - 400K elements) meshes in self-contact at interactive rates (5.8 - 50 FPS).