I'm drawing a blank on the matte passes with mental ray for Maya 2016.

I get that checking the "Use Matte Passes" will set up a mentalrayOutputPass and mentalrayUserBuffer and mip_rayswitch that somehow come together to create a new render pass for each mila material.

What I don't get is how to create matte pass material sets. I click the button and am faced with the relationship editor. What do I put in the set? No matter what I do, there is no set rendered in a pass. In fact the new mentalrayOutputPass node that gets created has Renderable unchecked, and it always unchecks itself if I check it.

The documentation for this is worse than non-existant, because if I'm not mistaken this is all outdated: https://knowledge.autodesk.com/suppo...FC535-htm.html

And the relevant node is apparently deprecated: https://knowledge.autodesk.com/suppo...BE26C-htm.html