When setting matid at texture level, then the multimatte doesnt work as expected with bercontiles. For example, set a multitexture as the tile color and set its id to 1. Add a vraycolor for the edge color, and set its id to 2.
Render. The result is single solid colour multimatte
Use the same multitexture and vraycolor in a max tile texture instead of bercontile, then the multimatte works as expected and you get 2 color multimatte.
I need to use the bercontile version, so for now I will cheat it with a vrayblend and set the matid at material level, using a mask for the joins. But this is a bit of a workaround. Would be nice if the 1st method works as expected
(or would be nice if chaos comes up with a bercontile replacement even, that works with GPU!)
The issue is BerconMaps-related - internally it calculates both textures with the second always overriding the MatID.
Another workaround that might be helpful is to enable ‘Color 2’ and set a duplicate of the map from the Edge slot without a Material ID channel (0). This would produce identical results and the desired Multimatte render element.