Hi all,

how do I (manually) compute the normals for a mesh loaded from a FBX file?

I already know how to do this mathematically, and know that there is KFbsMesh::GetPolygonVertexNormal(), but this is more of an overview question:

Which of these variants is right, and how do I know which one should be used or was intended by the model artist who created the FBX file:

- “Hard” or “facetted” sharing, where the vertex normals are identical to the triangle normals.
- “Smooth” shading, where the vertex normals are the averages of the normals of all triangles “using” that vertex.
- “Smooth” shading as above, but weighting the triangle normals e.g. by their area or angular extend at the vertex.

Is information available with a mesh which of these methods should be used?
Is smoothing groups information available for the triangles of a mesh?

Are normal maps supposed to follow tangent space ("smooth") or object space ("hard")?

My intention is to update the tangent-space of an animated mesh, but even if the FBX SDK could do this for me, I’d love to understand the proper approach how the normal vectors are properly computed from scratch.

Many thanks and best regards,
Carsten

Best regards,
Carsten

http://www.cafu.de