Mirroring normal maps?

wannabeartist

Hi guys,

I'm having trouble getting proper normal maps from xNormal, when I have opposite sides of a model sharing the UV space - I really thought that I had done this before without any problems, but now suddenly it doesn't seem to work.

So tell me, should it work? For example, you have a pair of shoes and you want them to use the same UV space - is it possible? I'm getting one shoe ok and the other with flipped normals (obviously)

Am I missing something or was I just imagining that it should work?

EarthQuake

Offset one side exactly 1 unit in uv space, this will ensure the texture still lines up, but prevent any errors from overlapping uvs when baking.

Psyk0

Did you move the overlapped UV's?

To prevent the mirrored UVs from causing overlaps or baking errors, move the mirrored UVs out of the 0-1 UV space, so only one copy of the non-mirrored UVs is left within the 0-1 square.

http://wiki.polycount.com/NormalMap#Mirroring

Disregard if you did...

wannabeartist

thanks guys,

I didn't remember that - but now I moved them.

But my normals are still wrong - the light is "mirrored". I moved them in the U axis -does it matter which axis you use?

EarthQuake

It would help to know what software you're baking in, what software you're viewing in, what type of normal map you're baking(must use tangent for mirroring), etc.

wannabeartist

Yes, of course...

I'm baking with xNormal and viewing it in Max. It is a tangent map.
The actual destination is Unity3D, but I haven't taken it there yet.

wannabeartist

Aah.... now that I took it to Unity, it seems fine