Hey this has probably been answered somewhere but I couldn't find it.
I'm working in UDK more extensively and I have models that have their UV's split right down the middle.
I flip the UV's and stack them. When I import it into UDK I get a nasty seam from the normals where the two mirrored sides meet.
I heard there is a material that fixes this in UDK but I wasn't sure what it was...