A Texture Synthesis Method for Liquid Animations

Abstract

Liquid simulation techniques have become a standard tool in production environments, producing extremely realistic liquid motion in a variety of films, commercials, and video games. Surface texturing is an essential computer graphics tool, which gives artists additional control over their results by allowing them to stylize surfaces or add detail to a lowresolution simulations. For example, an artist could use texturing techniques to add the appearance of foam to a wave, bubbles to beer, or fat globules to soup. Unfortunately, texturing liquid surfaces is difficult because the surfaces have no inherent parameterization. Creating a temporally consistent parameterization is extremely difficult for two primary reasons. First, liquid simulations are characterized by their complex and frequent topological changes. These topological changes result in significant discontinuities in any parameter tracked on the surface. Second, liquid surfaces tend to stretch and compress dramatically over the course of a simulation. Similarly, an advected parameterization will also stretch and compress. For these reasons, advected texture coordinates are often unsuitable for texturing liquid surfaces. In this sketch we present a method for generating textures on animated liquid surfaces. Rather than advecting texture coordinates on the surface, we synthesize a new texture at every frame. We initialize the texture with color values advected from the surface at the previous frame. We then run an optimization procedure which attempts to match the surface texture to an input sample texture and, for temporal coherence, the advected colors.