Lighting models used in the production of computer generated feature animation have to be flexible, easy to control, and efficient to compute. Global illumination techniques do not lend themselves easily to flexibility, ease of use, or speed, and have remained out of reach thus far for the vast majority of images generated in this context. This paper describes the implementation and integration of indirect illumination within a feature animation production renderer. For efficiency reasons, we choose to partially solve the rendering equation. We explain how this compromise allows us to speed-up final gathering calculations and reduce noise. We describe an efficient ray tracing strategy and its integration with a micro-polygon based scan line renderer supporting displacement mapping and programmable shaders. We combine a modified irradiance gradient caching technique with an approximate lighting model that enhances caching coherence and provides good scalability to render complex scenes into high-resolution images suitable for film. We describe the tools that are made available to the artists to control indirect lighting in final renders. We show that our approach provides an efficient solution, easy to art direct, that allows animators to enhance considerably the quality of images generated for a large category of production work.

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.