Physicsforests: real-time fluid simulation using machine learning

PhysicsForests is a fluid-simulation framework that can simulate large scenes with several million particles in real time, including surface generation, foam, rigid-body coupling, and rendering. Instead of solving underlying Navier-Stokes equations, it predicts particle behavior approximately using machine-learning-based regression-forest method that is trained on a large set of randomly generated scenes obtained by a traditional fluid solver. The result is faster and more stable than standard methods. The simulation does not diverge even if the incompressibility constraint cannot be satisfied, for example in case of an extremely aggressive impact caused by user interaction. The parametric-input feature vector allows for simulation of a wide range of materials, differing in density, viscosity, static friction, or surface tension, and coupling of fluids with rigid bodies or with each other.