Particle

Particle is a GPU-accelerated particle-based solver that simulates fluids and granular materials by treating them as collections of interacting particles. Each particle carries physical properties like density, pressure, and velocity, and interacts with neighbors within a smoothing radius. The solver supports three material modes: Fluids-SPH for liquid simulations using Smoothed Particle Hydrodynamics, Fluids-PBF for Position Based Fluids, and Grains for granular materials like sand with repulsion and attraction forces.

The simulation computes particle interactions through neighbor searches within the smoothing radius, calculating density-based pressure forces to maintain target density and optional viscosity forces for fluid thickness. You control the physical behavior through parameters like target density (incompressibility), viscosity (fluid thickness), cohesion (particle stickiness), surface tension (droplet formation), and adhesion (sticking to surfaces). The solver uses substeps and iterations to improve stability and accuracy, with adjustable time scaling for slow-motion or accelerated effects.

Particle supports multiple collision types including ground planes, bounding boxes, arbitrary collision geometry, and volumetric container geometry for creating vessels. This makes Particle suitable for water splashes, pouring liquids, sand and debris, viscous fluids like honey, and interactive particle-based effects.