A Simple Physically-Based 3D Liquids Surface Tracking Algorithm

Navier-Stokes-based methods have been used in computer graphics to simulate liquids, especially water. These physically based methods are computationally intensive, and require rendering the water surface at each step of the simulation process. The rendering of water surfaces requires knowing which 3D grid cells are crossed by the water’s surface, that is, tracking the surface across the cells is necessary. Solutions to water surface tracking and rendering problems exist in literature, but they are either too computationally intensive to be appropriate for real-time scenarios, as is the case of deformable implicit surfaces and ray-tracing, or too application-specific, as is the case of height-fields to simulate and render water mantles (e.g., lakes and oceans). This paper proposes a novel solution to water surface tracking that does not compromise the overall simulation performance. This approach differs from previous solutions in that it directly classifies and annotates the density of each 3D grid cell as either water, air, or water-air (i.e., water surface), opening the opportunity for easily reconstructing the water surface at an interactive frame rate.