Multiple UV Channels in Blender

Despite there being no need for you to retain a second UV channel on your meshes for light baking purposes, there are certain situations which arise (principally in fancy Material setups: see above) which necessitate the need for that second layout.

While many forums (which I painstakingly Google'd) will swear that no such thing exists, I happened to stumble on this particular holy grail when researching a completely unrelated matter...

And here's the proof:

It's in the object data properties panel of your mesh. Hurrah. Simply add a new channel, select it, redo the UVs as you wish, and you're done.

Or not.

It seems that unfortunately while the Unreal Exporter (see below) will export the mesh absolutely fine, it will only retain one of the two (or more) UV channels: principally, whichever you left selected.

This is a problem.

Fortunately the solution comes from a quite unforeseen direction: The FBX Exporter. The very same FBX exporter which I had previously dismissed as being too out of date to be usable in the latest versions of UDK . Yes, it seems that my previous attempts as importing meshes through this means had been with meshes which were just too damned shoddy (and it's here that I return to that old selling point of the Unreal Exporter: debugging at export time, not import...).

Yes, long story short: Use the FBX Exporter - just be sure to polish up your mesh according to the same requirements which the Unreal Exporter upholds.