The article focuses on modeling water for computer animation. An ongoing goal for computer graphics is to provide tools not only for the artistic rendition of our physical world but for re-creating as much of our world in as realistic a way as possible. The reasons for wanting greater physical realism vary depending on the application. Modeling physics on a computer and visualizing the results using graphics techniques can lead to complex pictures as dazzling as the real-world phenomena they are intended to represent, especially for such fluid effects as the motion of water, fire, and smoke. Mechanical engineers and physicists have been modeling the behavior of liquids on computers for nearly 40 years. A pragmatic approach to the problem of water simulation is described in this article. The system for modeling and animating the interaction between realistic-looking water and a computer graphics environment described in this article, draws on the science of computational fluid dynamics to calculate an approximate velocity field describing the time-varying motion of a volume of water.