So I have this model that I’ve unwrapped:
And I’ve been using xNormal to extract a normal map from my high poly mesh:
And this is the normal map I get:
It’s really yucky. Can anyone spot what might be wrong with the models or the way I unwrapped it that might be causing the problem? This is something I run into a lot, I could really use some help!
Are your normals pointing out?
“Ctrl + N”
You can visualise your normals in Edit Mode, in 2.49 look for the “Mesh Tools More” panel under “Editing Buttons”, dunno for 2.5 but i’m sure they’ll be there…
Normals are pointing out correctly.
What does the normal map look like when you bake it in blender ?
Where is your blend file ?
Well, I tried baking it in blender, and it worked exactly the way I had hoped. Apparently the problem was with xNormal and not with the model or the way I unwrapped it. Thank you for the suggestion, Richard.
What you could also do is make your normals in gimp, whick is what i do. But you have to download the plug in 
Making normal maps with baking from high to low poly will always surpass the results what could be achieved with painting normal map in gimp/photoshop or with normal map plugin.
I’m probably doing it wrong, but my normal maps look crap when baking them. If I create a b&w bump map in Gimp and convert it to a normal map it comes out much cleaner…although it requires a lot more work. Maybe by “high resolution” mesh, people mean “ridiculously high resolution”? All my machine can handle is subdividing a low-poly mesh 4 or 5 times, so that’s what I’ve worked with. A head with approximately 800 quads subdivided 4 times allows me to sculpt detail that looks nice enough on the mesh, but the resulting normal map is a mess. Areas that look smooth on the mesh end up with pits and bumps when rendered.
the problem is that there are multiple UV coords sharing the same space. You need to re-unwrap, or seperate the overlapping coords into islands.
@Modron: Not sure if you were replying to me or to Ronnie. If me, then I’d have to say I don’t understand why that should be a problem. Mirrored UVs sharing the same space is a very common method of creating textures for symmetrical objects. The high-poly mesh was sculpted with X-axis mirror, so the mapping “should” be mirrored exactly…shouldn’t it? It works out fine with my hand-made bump maps, anyway.
Reset object’s scale. Ctrl+A.
