This work is 32 Bit HDR Radiosity Normal Mapping. I usually use the same method for all of my realtime project. Radiosity Normal Mapping is a method that have been used in Half-Life®2 / Valve Source™Shading. In Radiosity Normal Mapping, we transform our basis into tangent space and compute light values for each vector. Therefore we will have 3 Directional lightmap.
http://www2.ati.com/developer/gdc/D3DTutorial10_Half-Life2_Shading.pdf
Turtle render engine for maya support Radiosity Normal Mapping. With turtle for maya we can bake and see radiosity normal map directly in maya plus other stuff.
http://www.illuminatelabs.com/turtle/technical-specifications
I build the hlsl shader for Quest3d with ShaderFX. Also normal map should be world space instead of tangent space. Its possible to do the conversion inside maya. Also you can combine world space normal map with directional occ to have a self shadow for your texture. The model itself is one of my old works. The plunge win a 3th place in Quest3d 2008 competition.

Related links
http://forum.quest3d.com/index.php?topic=63520.0
http://www.lumonix.biz/yabb/YaBB.pl?num=1191220107
http://www.gamedev.net/community/forums/topic.asp?topic_id=470296