Rendering to texture, or "texture baking,” allows you to create texture maps based on an object's appearance in the rendered scene. The textures are then “baked” into the object: That is, they become part of the object via mapping, and can be used to display the textured object rapidly on Direct3D devices such as graphics display cards or game engines.
When you render to texture or “bake” a texture, you choose one or more elements to render. These elements save aspects of the rendered scene: its geometry, lighting, shadows, and so on.
You can render to textures using the Scanline Renderer or the mental ray renderer. The iray renderer and Quicksilver Hardware renderer don't support Render To Texture.
Baked textures appear correctly—that is, as they would in a game engine—when you view the scene using Nitrous viewports or a Direct3D display driver.