Normal Map Flips When Geometry is Mirrored

[Caveman]

Hi, I have created normal maps for one hand and when I symmetrize the hand the Normal Maps which I have created for the right hand gets inverted on the left hand. How do I fix it. Is there an option somewhere? In Maya there is a check box called derive from Maya (something like that) in the render settings which fixes it.

Please help.

Thank you.

[Caveman]

Hi it's called Maya derivatives. Is there anything similar or better in Softimage.

[j3st3r]

It's because the mirroring changes the order of vertices in a given face, and because mirroring is technically a -1 scale on the mirroring axis.

If you use rendering, it might help to use the unbiased tangent or normal options in the XSINormalMap3 compund (I do not know atm which to try, it's up to you), and probably it'll fix it. Also check, if the normals point into the right direction. It's good to freeze the transform (at least the scale) and the modeling history too.

Also you might try to add tnagent property, and tell the normal map to use it.

And of course bomb Autodesk with request for decent realtime content creation support as I do