Particle Merging-and-Splitting

TL;DR

This paper presents a merging-and-splitting scheme for particle collision handling in simulations, effectively preventing inter-penetrations and enabling coupling of different simulation systems.

Contribution

The paper introduces a simple, robust merging-and-splitting method for collision handling in particle simulations, improving stability and compatibility across systems.

Findings

Effective collision handling without inter-penetration.

Robust in complex solid-fluid interactions.

Enables coupling of incompatible simulation systems.

Abstract

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.