What needs a prepass calculation?

hi all.

I’d like to know everything that would make VRay calculate a prepass. I have a file that has no materials except a VRay light material overriding everything.

No GI, no lights, no maps, no caustics. It’s basically a white render using a VRay Light Material with a VRay toon to produce my render.

It is pulling all the geometry from XRef’s that aside from that it’s really basic setup.

What needs a prepass calculation apart from GI?

Thanks in advance.

Andy

SSS will do that, even when using BF

A while back it was reported that it affects the scene, even when using override. What vray version are you on, I thought they fixed this long time ago (the override part, not the prepass part)