Particle Merging-and-Splitting

• Published in: IEEE transactions on visualization and computer graphics 2022-12, Vol.28 (12), p.4546-4557
• Main Authors: Truong, Nghia, Yuksel, Cem, Watcharopas, Chakrit, Levine, Joshua A., Kirby, Robert M.
• Format: Article
• Language: English
• Subjects: Collision avoidance; collision handling; Collisions; Computational modeling; Couplings; Fractures; Handling; Mathematical model; Numerical models; Particle measurements; Particle-based simulation; Simulation; Solid modeling; solid-fluid coupling; Splitting
• ISSN: 1077-2626; 1941-0506
• DOI: 10.1109/TVCG.2021.3093776

Robustly handling collisions between individual particles in a large particle-based simulation has been a challenging problem. We introduce particle merging-and-splitting , a simple scheme for robustly handling collisions between particles that prevents inter-penetrations of separate objects without introducing numerical instabilities. This scheme merges colliding particles at the beginning of the time-step and then splits them at the end of the time-step. Thus, collisions last for the duration of a time-step, allowing neighboring particles of the colliding particles to influence each other. We show that our merging-and-splitting method is effective in robustly handling collisions and avoiding penetrations in particle-based simulations. We also show how our merging-and-splitting approach can be used for coupling different simulation systems using different and otherwise incompatible integrators. We present simulation tests involving complex solid-fluid interactions, including solid fractures generated by fluid interactions.