B. Solenthaler ∗ University of Zurich R. Pajarola † University of Zurich
Figure 1: Three examples produced with our incompressible simulation: (Left) 2M particles splashing against the simulation boundaries. (Center) Close-up view of a wave tank. (Right) A ﬂuid represented by 700k particles colliding with cylinder obstacles.
We present a novel, incompressible ﬂuid simulation method based on the Lagrangian Smoothed Particle Hydrodynamics (SPH) model. In our method, incompressibility is enforced by using a predictioncorrection scheme to determine the particle pressures. For this, the information about density ﬂuctuations is actively propagated through the ﬂuid and pressure values are updated until the targeted density is satisﬁed. With this approach, we avoid the computational expenses of solving a pressure Poisson equation, while still being able to use large time steps in the simulation. The achieved results show that our predictive-corrective incompressible SPH (PCISPH) method clearly outperforms the commonly used weakly compressible SPH (WCSPH) model by more than an order of magnitude while the computations are in good agreement with the WCSPH results. CR Categories: I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling—Physically based modeling; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism— Animation. Keywords: ﬂuid simulation, SPH, incompressibility
process and thus renders particle methods less attractive for high quality and photorealistic water animations. In the context of Smoothed Particle Hydrodynamics (SPH), two different strategies have been pursued to model incompressibility. First, the weakly compressible SPH (WCSPH) method has been used where pressure is modeled using a stiff equation of state (EOS), and second, incompressibility has been achieved by solving a pressure Poisson equation. Although both methods satisfy incompressibility, the computational