Exclude shadow casting per object?

[gardocki]

I've got what I think is a fairly common situation, but I haven't found an easy way to accomplish it. I am compositing some CG elements with a live footage plate that was shot in a forest. There's a lot of natural shadows from trees and things on the actors, so I am using some fake gobo geometry to mimic the same shadows on the CGI elements. However...I need the matte shadow catchers in my scene to ignore the gobo objects. I can't exclude them from the vray lights because they still need to cast shadows. Is there a solution without having to do multiple renders to isolate them?

[nikolay.kusht]

Could you give us more details or perhaps, share with us some scene as an example with some screenshot so we could take a look and try to find any possible workflow.