Learning contact corrections for handle-based subspace dynamics

Fig. 1. The left images show a dynamic simulation of an FEM Neo-Hookean jelly with 12,469 triangles. The deformation is rich but slow (20 fps). The central images show the same scene using a linear subspace model built with just 8 point handles. The simulation is fast (420 fps), but it misses all the detail and suffers distortion under moderate forces. The right images show the result with our model, which augments the linear model with nonlinear learning-based corrections. We retain fast dynamics close to the linear model (140 fps), but we recover the detailed contact-driven deformations of the full model.

This paper introduces a novel subspace method for the simulation of dynamic deformations. The method augments existing linear handle-based subspace formulations with nonlinear learning-based corrections parameterized by the same subspace. Together, they produce a compact nonlinear model that combines the fast dynamics and overall contact-based interaction of subspace methods, with the highly detailed deformations of learning-based methods. We propose a formulation of the model with nonlinear corrections applied on the local undeformed setting, and decoupling internal and external contactdriven corrections. We define a simple mapping of these corrections to the global setting, an efficient implementation for dynamic simulation, and a training pipeline to generate examples that efficiently cover the interaction space. Altogether, the method achieves unprecedented combination of speed and contact-driven deformation detail.