Title
Small steps in physics simulation
Abstract
In this paper we re-examine the idea that implicit integrators with large time steps offer the best stability/performance trade-off for stiff systems. We make the surprising observation that performing a single large time step with n constraint solver iterations is less effective than computing n smaller time steps, each with a single constraint solver iteration. Based on this observation, our approach is to split every visual time step into n substeps of length Δt/n and to perform a single iteration of extended position-based dynamics (XPBD) in each such substep. When compared to a traditional implicit integrator with large time steps we find constraint error and damping are significantly reduced. When compared to an explicit integrator we find that our method is more stable and robust for a wider range of stiffness parameters. This result holds even when compared against more sophisticated implicit solvers based on Krylov methods. Our method is straightforward to implement, and is not sensitive to matrix conditioning nor is it to overconstrained problems.
Year
DOI
Venue
2019
10.1145/3309486.3340247
Proceedings of the 18th annual ACM SIGGRAPH/Eurographics Symposium on Computer Animation
Keywords
Field
DocType
physics-based animation, real-time simulation
Dynamical simulation,Matrix (mathematics),Stiffness,Computer science,Algorithm,Integrator,Constraint satisfaction problem,Real-time simulation
Conference
ISBN
Citations 
PageRank 
978-1-4503-6677-9
0
0.34
References 
Authors
0
7
Name
Order
Citations
PageRank
Miles Macklin124817.11
Kier Storey200.34
Michelle Lu300.34
Pierre Terdiman400.34
Nuttapong Chentanez567538.02
Stefan Jeschke6164.75
Matthias Müller7392.97