Editing Textures on Probuilder Objects

I'm creating geometry for a 3d level with probuilder. I have no problems building objects and painting textures with the Material editors. But I cannot figure out how to take the textures of an object out of Unity and edit them in either Photoshop or Substance Painter.

What I specifically want to do is add specific elements like signs or dust, dirt and scratches or normal maps for details (in Substance Painter). I can easily do this with non-probuilder objects, but I cannot for the life of me figure out how to achieve the same thing with probuilder objects. I've tried exporting the objects as an OBJ, but that hasn't worked very well. I think this would be a far better approach than trying to use decals, and while it would increase the number of textures in my game, I think the results would be better.

So please, anyone have any ideas or suggestions?

 

ProBuilder objects, like all renderable objects in Unity, don't contain Textures.

ProBuilder MeshRenderers have been set to use Materials.

Materials can be configured to reference Textures, for various reasons such as diffuse, normal, etc.

So somewhere you have a Texture going into your Material that the ProBuilder object is using. That's the place to start looking.