An important consideration in how many materials render is how they are “mapped” to the surfaces of the objects they are assigned to. This is especially important for materials that use bitmaps to define the diffuse color of a material, or the bump and cutout special effects.

As an example, you might have scanned a picture of wood grain for use in a material, but when the material is applied to an object, how large should the image of the wood grain be? Which way do you want the grain to run, and how do you want the grain to wrap around the corners of a three-dimensional object?

How two-dimensional maps are applied to three-dimensional surfaces is represented by mapping coordinates, which are stored as UVW coordinates. Revit assigns UVW coordinates to object components, so in cases where mapping coordinates are important to the rendered appearance of an object, 3ds Max translates these coordinates and stores them in the object mesh that is displayed and rendered in the 3ds Max scene.