Data only materials would be one solution that would resolve my main reason for not using materials - the need to manage Class attributes and Material attributes for items that are made of the same material (in the real world sense) but are in VW objects that accept or don't accept Material definition.  For instance, if I have a wall with maple finish panels (wall component defined as a Material) with a matching maple finish door (PIO set by Class) inserted into it, I have to maintain and coordi