Rendering Layers/Matte with Vray

[Trumble]

I've been trying to find a good answer everywhere, and as of yet, haven't found one.

I'd just like to be able render out separate passes for each major element in a scene with everything else matte and then composite them back together in post. Ie/ One pass for cars, one pass for ground elements, one pass for trees etc.

 

My problem is that when I render these layers out with everything else matte, the GI isn't the same as if everything was in the scene and it doesn't look as good. AND, I can't seem to get just a straight shadow pass that overlays the layer beneath it.

 

The big reason I'd like to do this is I'm faced with extremely tight deadlines left, right and centre, and as much as it would take extra effort to set it up this way, if there was a mistake on one layer (say a single car amongst others zooming by far too quickly by accident) I'd be able to just re-render the cars and not the entire scene.

 

If anyone has info on how to do this I would appreciate the help. Thanks

[RobNJ73]

http://cg.tutsplus.com/tutorials/chaos-group-vray/compositing-v-ray-render-layers-in-photoshop/

 

Good, handy reference I stumbled on a while back... hope this is what you were looking for.