VRayRhino 1.5 does not have a matte shadow feature? 
It is requested by a very high priority.
Thanx!
Hi Flat
Unfortunately VfR 1.5 doesn’t have matte shadow yet. This is something that we want to include in the future.
Best
I attended the recent Novedge webinar on V-Ray 1.5 hoping to see this very feature, which has been on the wishlist for years, and was disappointed to see it hasn’t been included yet. Come on guys, we need this!
It does seem like it would be easy to implement (other 3D apps have had it for 10 years) as well as extremely useful.
I don’t know if we have it in the public builds, but the nightly builds have the VRayMtlWrapper which allows you to do this. It will be available soon.