Deformable Objects Collision Handling with Fast Convergence
Computer Graphics Forum (Special Issue of Pacific Graphics'2015), Wiley, 2015, 34(7): 269-278.
Siwang Li, Zherong Pan, Jin Huang, Hujun Bao, Xiaogang Jin
Eight dinosaurs fall together. Collision
decoupling scheme is adopted to handle the complex constraints
efficiently,while stability and robustness are still preserved.
Abstract
We present a stable and efficient simulator for
deformable objects with collisions and contacts. For stability, an
optimization derived from the implicit time integrator is solved in each
timestep under the inequality constraints coming from collisions. To
achieve fast convergence, we extend the MPRGP based solver from handling
boxconstraints only to handling general linear constraints and prove its
convergence. This generalization introduces a cost of solving dense
linear systems in each step, but these systems can be reduced into
diagonal ones for efficiency without affecting the general stability via
pruning redundant collisions. Our solver is an order of magnitude
faster, especially for elastic objects under large deformation compared
with iterative constraint anticipation method (ICA), a typical method
for stability. The efficiency, robustness and stability are further
verified by our results.