chapter  16
Global Illumination Algorithms
Pages 50

In order for global illumination computations to reach a photorealistic level of accuracy, it is necessary that all aspects of the image-generation pipeline are based in fundamental physics. More precisely, this means that the reflection properties of all materials are described by proper BRDFs1, the light sources are radiometrically modeled, the transport of light through the scene is computed accurately, and the display of the image uses accurate tone-mapping operators.