Cartoon animation style rendering of water

Abstract

We present a cartoon animation style rendering method for water animation. In an effort to capture and represent crucial features of water observed in traditional cartoon animation, we propose a Cartoon Water Shader. The proposed rendering method is a modified Phong illumination model augmented by the optical properties that ray tracing provides. We also devise a metric that automatically changes between refraction and reflection based on the angle between the normal vector of the water surface and the camera direction. An essential characteristic in cartoon water animation is the use of flow lines. We produce water flow regions with a Water Flow Shader. Assuming that an input to our system is a result of an existing fluid simulation, the input mesh contains proper geometric properties. The water flow lines can be recovered by computing the curvature from the input geometry, through which ridges and valleys are easily identified. © 2009 Springer-Verlag.