Lighting Functions for Realistic Images

摘要

We present a new method for representing light sources for use in realistic image synthesis. Each light source is described as a multi-dimensional function based on product tensor splines. This representation allows the radiance of the light sources to vary according to the direction of emission, wavelength, and position on the emitting surface. The product tensor spline lighting functions are easily evaluated, can be generated from sample rays and can generate samples for distributing light throughout the scene. The product tensor spline lighting functions have been incorporated into a wavelength dependent bidirectional ray tracing program and example images are provided which exhibit prismatic effects.