This is part of a job where we do “hybrid cgi” - we had to replace parts in a car interior photo with rendered parts. In this case the instrument panel is plastic and should be leather with stitches. Add the stitching was the easy part: some shrinkwrap, arrays, curve modifiers, some finetuning here and there - done 
The problem is that the mesh /cad data comes from the plastic mold instrument panel - so no bumps where the leather parts are stitched together. Now I made this bumps the same way as the stitching - looks promising so far, but how to solve the UVs? The bump-part should use the same UVs like the round cube - need this for the tiled leather texture later …
I need to unwrap these two meshes as if they where one piece (without touching the geometry of the cube).
Any ideas? :o
