I never thought I’d need to do this, but does anyone know of a method to turn a normal map into a greysclae height/bump map? I know this is a little backwards, but I need to manually edit a large UV set and doing it in greyscale would be much easier.
kill the saturation or just convert to grayscale? you might need to play with the levels then.
No, removing the saturation from a normal map will not generate a displacement map. A normal map encodes the normals at each pixel in the RGB values, wheras a displacement map encodes the height difference from a flat surface in each pixel.
To convert a normal map to a displacement map, you would have to somehow integrate the normal map.
Some googling gave me this site, which contains a tool called Displacement Map Creator, that should do exactly that. The only problem is that it requires a Win32 PC to run.
PS. The same page also describes a way to create normal maps from 4 differently lit photographs of a real object using Photoshop.
That’s what the dusty PC sitting in the corner is for 
I’m not sure I can get DirectX 9 to install on it though.
That’s really cool, I might have to build a little lightbox setup and test that out. Thanks Keli for the link.
Wow that is a great tutorial. If my gfx card could do bumpmaps I would be all over that in a second.