Global illumination

Global illumination refers to a class of algorithms used in 3D computer graphics which, when determining the light falling on a surface, takes into account not only the light which has taken a path directly from a light source (local illumination), but also light which has undergone reflection from other surfaces in the world.

Images rendered using global illumination algorithms are often considered to be more photorealistic than images rendered using using local illumination algorithms. However, they are also much slower and more computationally expensive to create as well.

Radiosity and [photon mapping]? are examples of global illumination algorithms.