Chapter 4

# Strategies for Computing Light Transport

## 4.1 Formulation of the Rendering Equation

The global illumination problem is basically a transport problem. Energy emitted by light sources is transported by means of reflections and refractions in a three-dimensional environment. We are interested in the energy equilibrium of the illumination in the environment. Since the human eye is sensitive to radiance values, and since we want to compute photorealistic images, we are primarily interested in radiance values or average radiance values computed over certain areas and solid angles in the scene. The latter means that we should compute flux values for several areas of interest, which will be referred to as sets. The exact geometric shape of these ...