Anyone know what code it uses to generate it's tangents? You can't feed explicit tangents in, it does that stuff itself. If I can find it, I'll throw together an xNormal plugin to bake normal maps synced to Source.
Hah, so I did some testing and as far as I can tell, the default MikkTSpace gives out exactly the same result as the Source Engine synced version I wrote. Well, that was a nice excercise, at least...
If I could just interrupt with some noob questions that get progressively off topic: When you say 1 smoothing group cube, do you mean a cube where all faces are smoothed + continuous (t net I guess) UV's, or a cube with no smoothing (all hard edges / split uv's)? If it's the former is the idea to show that the normals are…