Steerable illumination textures
Michael Ashikhmin, Peter Shirley · ACM Transactions on Graphics · 2002
We introduce a new set of illumination basis functions designed for lighting bumpy surfaces. This lighting includes shadowing and interreflection. To create an image with a new light direction, only a linear combination of precomputed textures is required. This is possible by using a carefully selected set of steerable basis functions. Steerable basis lights have the property that they allow lights to move continuously without jarring visual artifacts. The new basis lights are shown to produce images of high visual quality with as few as 49 basis textures.