In addition to standard materials, you can use compound materials. Most compound materials combine two or more sub-materials. Compound materials are similar to compound maps, but they exist at the material level. Applying a compound material to an object inherently creates a compound effect that often uses mapping. You load or create compound materials using the Material/Map Browser.
Using a filter control, you can choose whether the Browser lists maps or materials or both.
Different types of materials create different effects, behave in particular ways, or are provided as ways to combine multiple materials.
Note: The submaterial buttons and submap buttons for most materials and maps have checkboxes beside each button. These let you disable or enable that branch of the material or map. For example, in the Top/Bottom material, the Top Material and Bottom Material buttons each have checkboxes. Similarly, the Checker map has two map buttons, one for each color. Each button has checkbox beside it that lets you disable that color’s map.
These are the different kinds of compound materials:
Blend: Blend materials, like Mix maps, combine two materials by mixing their pixel colors.
Double Sided: Double Sided materials also store two materials. One material is rendered on the object’s outer faces (the usual side for one-sided materials, as determined by face normals), and the other is rendered on the object’s inner faces.
Matte/Shadow: Matte/Shadow material is used specifically for creating matte objects to use with environment maps. Strictly speaking, it isn’t a compound material because it doesn’t combine other materials: but it doesn’t fit into the standard category, either.
Multi/Sub-Object: Multi/Sub-Object materials are a general way to let you assign more than one material to the same object. The Multi/Sub-Object material stores two or more sub-materials, which you assign at the sub-object level by using the Mesh Select modifier. You can also assign the sub-materials to whole objects by using the Material modifier.
Raytrace: Generates accurate, fully raytraced reflections and refractions. Strictly speaking, Raytrace is not a compound material, but it differs from standard material, using a more realistic color model.
Top/Bottom: Top/Bottom materials store two materials. One material is rendered on an object’s top faces and the other on the object’s bottom faces, depending on whether a face normal points up or down.
This option is available only when you’re at the material level in the Material Editor; otherwise, it’s grayed out.