Diffuse inter-reflection
Diffuse inter-reflection is a process whereby light reflected from an object strikes other objects in the surrounding area, illuminating them. Diffuse inter-reflection specifically describes light reflected from objects which are not shiny or specular. In real life terms what this means is that light is reflected off non-shiny surfaces such as the ground, walls, or fabric, to reach areas not directly in view of a light source. If the diffuse surface is colored, the reflected light is also colored, resulting in similar coloration of surrounding objects.
In computer graphics, diffuse inter-reflection is an important component of global illumination. There are a number of ways to achieve diffuse inter-reflection. Radiosity is one of the most common techniques in use.