I've tried to find a way to tell whether the UV shell is flipped or not but couldn't find any. There's an error in the Maya help file for the polyEvaluate command in the mel section. It states that for the -boundingBox2d flag, the mel command will return the UV coordinates for the bounding box as 4 float values in Mel and…
I had a look at the UV MEL commands and there doesn't seem to be anything to easily query for overlapping. I take it you'd want this for prepping for baking? Is it safe to assume that the overlapping UV part is identical to the underlying one when it comes to shape and UV-space-position?
It's not about how to actually do it manually. I should have mentioned more clearly in my first comment that I'm interested on how to query this in mel :( It's just that with some meshes that have flipped overlapped UVs, not all flipped shells are easily selectable in the 3d view as they aren't always on the same side and…