Hi,

Got a problem exporting models from 3dsmax 2008 via FBX. All meshes mirrored in 3dsmax turn out weird. I believe the order of the vertices in the facelist is reversed, thus backface culling gets confused. In XNA i only see the wrong side of the mesh all the time.

Anyway this problem doesnt occur with the Panda X exporter. I tried the 2006_11_2 version FBX available from autodesk, but no success, same problem.

Anyone got a idea?

Thanks in advance, Alex

The cause of the problem is likely either a bug in the XNA FBX importer, where it doesn't pay attention to the mirror information about triangles, or it is a bug in the FBX exporter where it doesn't write that information -- I don't know which, but you can't fix it yourself no matter which it is.

To work around it, try adding a "Unify Normals" modifier on the mesh in Max before you export. If you're using Physique or Skin, then the Unify Normals modifier needs to go UNDER the Physique/Skin modifier.

There is also an option in the Model Importer to flip the triangle winding, if I remember correctly. If all triangles (not just some) are wrong, then using that option will work too.

Much appreciated for pointing this out. :)

I  agree that this is some kind of bug. Cant imagine that Autodesk would do such a silly thing though.

Since i use 3DSMAX 2008 the "Normal" modifier did the trick. Once the normals where flipped the mesh was displayed correctly.

Thanks again.

 

Does flipping the normals make it wrong in max, but ok in XNA ? if so you might want to try reset-xforms, then collapse the stack in Max, this cures 90% of issues with flipped normals, transforms etc. Its a step many artists use before exporting from Max.