Real-Time Large Scale Fluids for Games

This report presents an implementation of a stable height-field fluid solver on non-uniform quadtree grids. It build upon the well known techniques of height field representation of the fluid volume, semi-Lagrangian advection, upwind differencing in the discretized representation and adaptive quadtree grids for faster calculations. A novel contribution is the applications of certain concepts and techniques to the standard approaches. Smoothing kernel interpolation is used to enable semi-Lagrangian advection on a non uniform grid. A definition of a cell neighbor is introduced which doesn’t require the neighbor to be a quadtree leaf solves the problem of hanging nodes inherent to quadtrees. The model is suitable for water propagating over height field terrains in interactive environments like video games.