Render Elements require rendering of Main Pass
Currently in order to output a Matte pass (or any other render element) in 3ds Max, you are required to render the main image which could take hours, when the matte pass itself is rendered in mere seconds. The current work around is to disable shadows, reflections, refractions, final gather, GI, etc. in order to decrease render time for the main image. However, this is a pain to have to do.
AdminMartin B (Admin, Autodesk) commented
I understand that some passes need the whole calculation to be done. But e.g. Z-Depth should definitely be available as a "render element only".
"render element only" I'm in for that!
Thats why it is a PASS, because it renders WITH the main render. This is the logic behind passes. What you really want is a build-in render layer manager like in maya (RPManager, LPM, etc.)
so many things to fix... but this one is often annoying!
The title should be "render element only" ! :)