@Cyril Metahuman refuses to paint across materials

Hello Björn,

Thanks for the message. There's a simple explanation to this behavior. 

Substance Painter sorts the work in two categories: texture set > UV Tile.

A Texture set is basically a group containing UV tiles (UDIMs). You can paint across UV tiles, but not across texture sets.

But what's defining a Texture set? That's pretty simple; each time Substance Painter finds a new Material ID, it will create a new texture set. If Substance 3D Painter creates 4 texture sets, most likely the mesh has 4 different Material ID.

In your project, it seems all UDIMs have their own Material ID, creating a single texture set for each UDIM.

I suggest you to edit in your 3D software the mesh, and make sure it has only a single material applied.

Also, make sure you checked the UV tile workflow while starting a new project.

Regards,