Real Time 3D Fluid and Particle Simulation and Rendering

This application uses a GPU based 3D fluid solver with a moving domain to seamlessly advect hundreds of thousands of particles. We use a globally second-order accurate fluid simulation method which takes constant calculation time, leading to a highly turbulent but stable simulation suitable for use in a real-time situation. In this demo our solver is used to simulate the turbulent wake behind a car, and we render smoke transported through that wake with a hardware-based volume renderer. The simulation domain is at a fixed position relative to the car, and we exploit Galilean invariance to transform the moving simulation domain into a motionless domain with inflow and outflow boundary conditions. Particles are advected through this fluid, but seamlessly transition to simple Newtonian dynamics as they leave the simulation domain. After simulation, the particles are sorted using a GPU-accelerated radix sort, and then rendered as alpha blended sprites with motion blur and volumetric shadows.