In this paper we describe a system for animating flames. Stochastic models of flickering and buoyant diffusion provide realistic local appearance while physics-based wind fields and Kolmogorov noise add controllable motion and scale. Procedural mechanisms are developed for animating all aspects of flame behavior including moving sources, combustion spread, flickering, separation and merging, and interaction with stationary objects. At all stages in the process the emphasis is on total artistic and behavioral control while maintaining interactive animation rates. The final system is suitable for a high volume production pipeline. CR Categories: I.3.7 (Computer Graphics): Three-Dimensional Graphics and Realism