Hey guys -
I was testing out MayaLT to see how it behaves for Dota2 asset creation and noticed that one of the default options of the program might cause an issue.
Basically the 2013 release of Maya introduced 3 new options for mesh smoothing calculations (some of them are actually very cool in specific scenarios), with one of these new options being adopted as a new default. See the
Autodesk knowledge base, and
a Polycount thread on the subject.
The problem with that new default option is that it seems to be incompatible with the Source Engine Handplane workflow - at least from what I have noticed. In other words, an OBJ mesh built with this new default option enabled, along with an Object Space normalmap, processed through Handplane, seem to result in an incorrectly generated Source Engine Tangent Space normalmap. Like so :
Now I am not 100% sure that this recent Maya option is what actually caused my issue, but in practice, reverting it to the old "unweighted" style and re-smoothing my model gave me clean results once I generated my Source TS map and imported my asset into Dota2.
So my problem is now fixed ; but if you are running into the same kind of issue (something that indeed seems to happen to some workshop artists, if I remember correctly), maybe changing that option in the Maya preferences (and of course re-smoothing the entirety of your model again after that before re-exporting it to OBJ) might very well be a solution.
I hope this helps ! And let me know if this works. (And if I am completely mistaken let me know too ! )