Color bleeding

Color bleeding is a term that is used to describe the effect of a red carpet next to a white wall giving a pink tint to the wall. Color bleeding is a diffuse-to-diffuse effect.

In the following example, the sphere and box have constant, bright colors, and those colors “bleed” onto the diffuse ground plane.

Diffuse lighting
Image Unavailable

Let's compare both types of illumination. On the left, the box has only direct illumination. On the right, the box has direct illumination and one-bounce indirect illumination.

Cornell box - direct lighting
Image Unavailable
Cornell box - 1 bounce lighting
Image Unavailable

A slightly more involved example that mixes reflection/refraction effects with indirect lighting.

WinOSi test scene
Image Unavailable