Radiosity

Radiosity Wikipedia

Radiosity is a global illumination algorithm used in 3D computer graphics rendering. Radiosity is an application of the finite element method to solving the rendering equation for scenes with purely diffuse surfaces. Unlike Monte Carlo algorithms (such as path tracing) which handle all types of light paths, typical radiosity methods only account for paths of the form LD*E, i.e., paths which leave a light source and are reflected diffusely some number of times (possibly zero) before hitting the eye.

As a rendering method, radiosity was introduced in 1984 by researchers at Cornell University (C. Goral, K. E. Torrance, D. P. Greenberg and B. Battaile) in their paper "Modeling the interaction of light between diffuse surfaces". The theory had been in use in engineering to solve problems in radiative heat transfer since about 1950.