Maya LT 2017, extract/separate messes up mat IDs?

Autarkis

Hey guys,
I've had this issue pop up in the past, but always brushed it off... 
Object with various submat IDs.
Separate object, new sub objects are getting wrong materials assigned.
Select faces by materials, extract, new sub objects are also getting wrong mat id's assigned.

I swear for the life of me that this is recent behavior in maya (or an LT thing???) Anyone knows how to fix it or can point me to the right direction? My google fu is apparently weak.

throttlekitty

I have an old thread that relates to this, but I never really went back to update my findings. Short answer is that per-face material assignments in maya are fucked and have been for a long time, there's lots of operations that can sneak in and cause the issue. Short solution is to use this script instead of separate, you can also use this to fix meshes that ended up with bad shader assignments.

One caveat with detatchSeparate: say your model has three materials, and you select and puff off most/all of the faces of a single material. You'll need to reassign that material to the new object at Object level. So for fixing something, I... detach a set of faces of one material (usually doesn't matter which material), detach, assign mat again, and re-combine with the object again.

The easy way to tell if things are wonky is to use Hypergraph With Hierarchy. A model that should only have a single shader will have a pink line from the shape to the shading group node, you may see a blue and green looping connection and that's bad. Or multiple connections to the same shader. On models with multiple shaders, the node view might look exploded instead of the nicely framed view you usually get, and usually have those extra connections to the shaders.