Local Density Calibration for Position Based Fluids

抄録

This paper propose a improved PBF(position based fluid model)-based method for simulating realistic incompressible fluid flow. Our goal is to present simulation method of fluid phenomena as realistic as possible in realtime to many applications that require a high frame rate. Rapid fluid simulations are important for realizing real-time applications in computer graphics. Position based fluids (PBF) has been suggested as a practical method for real-time simulations of incompressible fluids. This method is based on the SPH(smoothed particle hydrodynamics) and realizes incompressibility by restricting the density. Furthermore, it reduces the calculation costs by allowing large time steps. However, because it iteratively calculates the density constraints, PBF is impractical for applications requiring high resolution and high frame rate. To increase the simulation speed of PBF, we replace the iterative density calculation by a density model. In the conventional method, iterating few density calculations compresses the simulated fluid. To resolve this problem, we consider the particle density and the direction of the fluid flow. We develop a computational model based on this hypothesis and verify its usefulness in simulations. The method suppresses the fluid compression even in a non-iterative model. We conclude that the proposed computational model effectively maintains a constant density in PBF.