We present a novel contact model, termed Offset Geometric Contact (OGC), for guaranteed penetration-free simulation of codimensional objects with minimal computational overhead. Our method is based on constructing a volumetric shape by offsetting each face along its normal direction, ensuring orthogonal contact forces, thus allows large contact radius without artifacts. We compute vertex-specific displacement bounds to guarantee penetration-free simulation, which improves convergence and avoids the need for expensive continuous collision detection. Our method relies solely on massively parallel local operations, avoiding global synchronization and enabling efficient GPU implementation. Experiments demonstrate real-time, large-scale simulations with performance more than two orders of magnitude faster than prior methods while maintaining consistent computational budgets.
@article{ankachen_2025_OGC,
author = {Chen, Anka He and Hsu, Jerry and Liu, Ziheng and Macklin, Miles and Yang, Yin and Yuksel, Cem},
title = {Offset Geometric Contact},
year = {2025},
issue_date = {August 2025},
publisher = {Association for Computing Machinery},
address = {New York, NY, USA},
volume = {44},
number = {4},
issn = {0730-0301},
url = {https://doi.org/10.1145/3731205},
doi = {10.1145/3731205},
journal = {ACM Trans. Graph.},
month = jul,
articleno = {160},
numpages = {21},
keywords = {physics-based simulation, elastic body, rigid body, time integration}