maps for paralax shaders

Unity Engine
1

Hi
ive notice now instead of one normalmap with alpha height map,these shaders use one normalmap and one heightmap marked (A).the documentation still describes the former way(2007).
so how does it work now?
just a normalmap with no alpha ,and then the heightmap in the alpha of empty image?
or the same normalmap+alpha heigthmap in both places?
i would like to know,please!
these shaders, along with relief shaders are very important in improving the quality of the meshes produced in Zbrush,Mudbox or 3DCoat!
would be possible in the futur to use vectordisplacementmaps as well, any how?
thanks

2

Unity 3 uses DXTnm normal map compression, which means there is no room for alpha channel data in the normal map. The parallax shaders still read height information from the alpha channel of the provided height map texture, though, which means you can use the Alpha 8 format.

3

thanks Man!