The problem with YAL is that it combines lightmaps into "surfaces" which are polygons that are adjacent and have similar normals.
If it just mapped each tri seperately, then it would be trivial to get the smoothing right.
The problem is not knowing which triangle the particular lumel you're mapping is in. Now, one could write a slow algorithm to figure this out after the fact, but it would really be much simpler and faster to toss out the special case stuff. There is no need to compress lightmaps so much in today's games.
If it just mapped each tri seperately, then it would be trivial to get the smoothing right.
The problem is not knowing which triangle the particular lumel you're mapping is in. Now, one could write a slow algorithm to figure this out after the fact, but it would really be much simpler and faster to toss out the special case stuff. There is no need to compress lightmaps so much in today's games.