Renders the material ID information assigned to objects.
Material ID information is useful when you are making selections in other image-processing or special-effects applications, such as Autodesk Combustion. For example, you could select all of the objects with a given material ID in Combustion. The material ID corresponds to the value you set for the material with the material ID channel. Any given material ID will always be represented by the same color. The correlation between a specific material ID and a specific color is the same in Combustion.