The Multi/Sub-Map shader provides the ability to assign different colors or maps to a single parameter of a material. For example, you could create an array of pebbles on a terrain and assign a single Arch & Design material to all of the pebbles. To introduce color variation, place a Multi/Sub-Map shader in the Diffuse slot of the material. In doing so, you would maintain the same BRDF properties for all pebbles, varying only the diffuse color. Judicious use of Multi/Sub-Map can vastly reduce the required number of materials in complex scenes.
Multi/Sub-Map can vary the assigned color or map at random, or based on object, material, or smoothing group ID. You can define up to 20 colors or maps to different IDs and for higher IDs you can repeat the assignment cycle or specify an out-of-range color or map.
Left: Auditorium seat colors vary by object ID
Right: Colors vary at random
Choose the basis on which to assign a color or map:
When on, the assigned colors/maps cycle through values higher than the Number Of Colors/Maps To Use setting. For example, if Number Of Colors/Maps To Use is set to 7, objects or faces with ID 8 or 15 would use Color/Map #1, IDs set to 9 or 16 would use #2, and so on.
When off, any IDs outside the specified range (1 to Number of Colors/Maps) use the Default/Out-of-range Color.
This rollout provides check boxes for enabling and disabling the map/color assignments and buttons for assigning maps.