Environment map

An environment map is used for three purposes in a game engine:

1. Reflections: simulates the look of a shiny surface, like chrome or water.
2. Refractions: simulates the view behind or through a transparent surface, like glass or water.
3. Background: simulates the distant view behind the game models.

An environment map is usually painted to look like an all-encompassing world.

In this example, the sky texture on the right has been used as a reflection on the torus.

Environment mapping can also be used to fake the look of specular highlights on an object, by painting only the light sources into the environment texture.

• Cube map
• Diffusely convolved cube map
• DuDv map
• Spherical environment map

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