How to render a Matte for all objects in scene?

[yourfather]

Hi. I have a scene with lots of items. How can i get mental ray (3ds max) to generate a matte for all the different items?

 

I might be using the wrong term. What i want is something like in a EXR file. An EXR file will automatically render a file with all objects a different color. This makes it easy for selecting different elements in post.

[yourfather]

Figured it out. Made simple materials in the Material Editor and gave each material its own Material ID (also found in the material editor). Then used Render Elements "Material ID" in the Render Setup Dialog. Turned off all lights and rendered.

 

Cool