Right now the lightmapTexture seems to only support a single full size texture for the lightmap texture2D call… Unity exports lightmaps as a texture atlas that it packs as many material lightmap textures as it can into a single lightmap texture for all the materials in the scene (provided the texture atlas is large enough… otherwise it splits into more than one texture atlas)…
The point is, i dont think the shaders support sampling just a portion of the lightmapTexture.
So basically all unity exported lightmaps are usesless.
Can we please add support for lightmap texture atlas (or if its in there already … how do i use it ???)