Fluid Animation on Arbitrarily-Shaped Structured Grids

In this paper, we present a fast and straightforward technique to simulate two-dimensional fluid flows on planar structured grids with arbitrary shape and parameterization. Although driven by a regular uniform grid, the resulting flows correctly follow and interact with arbitrary boundary walls and internal obstacles. This is accomplished by using Jacobian matrices to relate field derivatives in the world and parameter spaces, which allows us to solve the reduced Navier-Stokes equations directly in the latter. The technique is demonstrated by using a GPU-based Eulerian Stable Fluid solver to generate real-time animations of flows confined in river-like geometry with arbitrary boundaries.