Smoke Simulation

This report presents an approach for simulation of smoke and other gaseous phenomena. The method used builds mainly on the paper Stable Fluids by Jos Stam. This ensures that the simulations are unconditionally numerically stable. The Navier-Stokes equations that describe the motion of the fluid are divided into four components, which are solved term-by-term. Solving the diffusion and mass conservation terms involves solving large, sparse linear matrices. These are solved using an iterative numerical method called Gauss-Siedel relaxation. The presented results show real-time 2D simulation of smoke. The flow of the smoke is controlled by changing the viscosity and diffusion rate of the fluid, and insertion of external forces and density sources. Furthermore, simple internal boundaries are considered. The obstacles correctly hinder the fluid, but the current solver cannot manage objects that are thinner than two grid cells. Although the results are neither physically correct nor photorealistic, they show reasonably realistic behavior. The next step of the project is to extend the solver and the representation to 3D. This requires a volume renderer and possibly more sophisticated numerical methods.