Mixing two pbrmetallicroughnessBlocks' output color in nodeMaterial

Hi there, I’m trying to export Blender’s materials to BJS’s nodeMaterials, things works well until two Principled BSDF ‘blocks’ get mixed to reach the output.
I DO KNOW that it’s not allowed to put multi pbrmetallicroughnessBlocks in a nodeMaterial. Maybe it’s stupid but after some search it seems it is possible in my mind.
So if it is possible but designed be banned, or it is just impossible?
Or any hint about this with nodematerial?

Well if the material compiles we are good ;D
Not sure it is entirely supported but again if it works :smiley:

Sorry if I misunderstood your words, but we’re using our own exporter and trying to import it to BJS with nodematerials so that designers are able to change params with NME directly(NME is really a good tool for designers in my opinion). As far as I know the exporter in the doc can’t export nodematerials.

It is not possible to have two PBRMetallicRoughness nodes in the NME, it is not supported (it is also not supported in the regular PBRMaterial). You should try to combine the parameters of the two BSDF to produce a single BSDF. That’s what games do I think, as evaluating a single BSDF is already quite heavy.

I’ve thought of combining the params, but I’m not sure if it is the right approach. I’ll have a try to see the result. Thanks a lot for the explanation!