Rather than 'fly' Poser lights into an enclosed scene, I try to illuminate set by dialling any scene 'luminaires' to 'super-ambient'.

This is okay when the model part is split so the filament / bulb / source is allocated its own group, so its own texture. But what to do when entire luminaire --the bulb / tube, holder, shade, ferrule, cable & pattress-- forms one group, shares one texture map ?

Is there any way to 'mask' that shared texture map so that only eg the bulb region responds to 'super-ambient' setting ??

Alternative would need the model re-grouping so mesh for eg bulb may be allocated its own material, and that dialled to 'super-ambient'.

Not much of a problem when the set is low-poly but, if set's OBJ is 10~~20 MB with 60++ textures, becomes harder...