In order to use FaceID and Face MtlID in Multisub and UVWRandomizer maps we need to assign polys Mtl Id manually, right now the only way is to use Scripts, Could we have an automatic MtlID assign for poly, similar to Coronas behaivior?
Im sharing Coronas behaivior when using their MapRandomizer and Multisubtex in Polygon mode, as you will see, theres no need to asign material ids to polys in order to have randomization.
Meanwhile in Vray you need to asign materialids to polys in order to have randomization, I can use scripts to do that for me, but if you can autoasing them like Corona it will be very practical.
I have to mention that Corona also auto assigns object Id and material id for masking.
In V-Ray we need to assign them manually too, I dont care too much for that because of Cryptomatte but maibe some people will be interested in those masks