Precomputation-Based Rendering

High quality image synthesis is a long-standing goal in computer graphics. Complex lighting, reflection, shadow and global illumination effects can be rendered with modern image synthesis algorithms, but those methods are focused on offline computation of a single image. They are far from interactive, and the image must be recomputed from scratch when any aspect of the scene changes. On the other hand, real-time rendering often fixes the object geometry and other attributes, such as relighting a static image for lighting design. In these cases, the final image or rendering is a linear combination of basis images or radiance distributions due to individual lights. We can therefore precompute offline solutions to each individual light or lighting basis function, combining them efficiently for real-time image synthesis. Precomputation-based relighting and radiance transfer has a long history with a spurt of renewed interest, including adoption in commercial video games, due to recent mathematical developments and hardware advances. In this survey, we describe the mathematical foundations, history, current research and future directions for precomputation-based rendering.