I’ve created my own objects in Maya and UV mapped them all with no issues and no overlapping or flipped UV’s. However after importing them to Unreal Engine and attempting to build the lighting I get warnings that two of my objects have overlapping UV’s, one with 25 or so percent and the other with 50% overlapping. I’ve also noticed that after importing the objects, some of the edges became distorted as if the smoothing got screwed up. As I know next to nothing about UV mapping any help is greatly appreciated.
Take a look at the mesh in the mesh editor, you can see if the UVs look there. UE uses the material UVs on import to compute the lightmap UVs, so one being screwed up will lead to the other having the same problem.
Channel 0 is the material UV, channel 1 is the lightmap:
