Direct Raytracing of Particle-based Fluid Surfaces Using Anisotropic Kernels

Abstract

Particle-based simulation models have assumed a significant role in the numerical computation of high-fidelity transient flow and continuum mechanical problems. However, direct visualization of surfaces from particle data without intermediary discrete triangulation remains a challenging task. We demonstrate a novel direct raytracing scheme for free surface intersection based on anisotropic smoothing kernels. Our approach efficiently reduces the number of candidate kernels evaluated to converge to the surface threshold, thereby running in image space rather than object space complexity. We conduct comprehensive benchmarks with respect to data set size, scene complexity, visual fidelity and hardware setup. Our versatile system is suitable for both high quality and interactive desktop rendering, scales reasonably well even with trivial parallelization and renders up to 170 million particles on 32 distributed compute nodes at close to interactive frame rates at 4K resolution with ambient occlusion.