I see people mirror textures right down the middle pretty often, particularly in faces. I've always assumed this was a huge no-no because some game engines will miscalculate the specular info and create gnarly seams. But as I'm seeing it more and more now, is it a UDK-exclusive issue and most other engines support it just…
Yep, many engines do it fine. I've noticed there's often a hairline seam, but mostly it's not too noticeable. A trick on UDN for fixing the specular seam. http://udn.epicgames.com/Three/ContentBlog.html#Fixing%20specular%20highlights%20when%20using%20X%20and%20Y%20symmetrical%20texture%20mirroring One way to avoid it…