System Information
Windows 7 Enterprise 64-bit SP1
Geforce GTX 780
Blender Version
Broken: 2.72b
Worked: 2.71
Short description of error
When exporting a mesh as an FBX from Blender 2.71 it works well and the normals in Marmoset display correctly.
When opening the exact same scene and exporting the asset with the same settings I get normal artefacts.
Exact steps for others to reproduce the error
Just having a mesh with edgesplits and a correctly baked normal map should show the problem.
Meant to write "When opening the exact same scene in blender 2.72b and exporting the asset with the same settings as in 2.71 I get normal artefacts in Marmoset."
As usual, please attach files to help reproducing the issue.
In this case, ideally, a very simple object (like a low-poly sphere) in a .blend, and its export result from both 2.71 and 2.72.
Also, please check with a build from our buildbot (though probably nothing changed in this area of FBX exporter, always worth checking).
The asset is for a commercial project so I can't share it. I'll try to make another example.
So I noticed the export settings has tangent space greyed out in 2.72b if you have face smoothing set to on. I tried switching the face smoothing off and it seems to fix it in Marmoset at least.
Ah yes, that is expected. Having both smooth data (either face or edge ones) and normals/tangent space enabled was giving issues in some apps (after all, they are more or less about the same thing), so starting from 2.72 you have to choose one or the other, but cannot use both at the same time.
Thanks for the report, but no bug here.
Alright, sorry for the confusion. I did however not have the tangent space button checked in 2.71 either but the smoothing was set to face. In 2.72b I just removed the smoothing completely and kept the tangent space unchecked and it seemed to work. Is this the intended outcome? Because it seems to me the exact same settings in 2.71 behave differently from 2.72b.
Yes, vertex normals are exported if, and only if smooth edges/faces are disabled. Tangent space is an additional option (that only works together with vertex normals of course), but by default we only export vnors, without associated tspace.
In 2.71, vnors were always exported, disregarding face/edge smooth setting, which generated issues with some apps.
