Hey guys,

I am exporting a model rigged with blend shapes from Maya (2009) to FBX (2010). I have spotted two problems:

1. If I export without the option “Split per vertex normals”, the model gets proper normals but the blend shapes normals are exported incorrectly. I have checked with both my own program and reimporting to Maya, and I can see wrong blend shape normals in both cases, which seems to point to a problem in the FBX SDK.

If I export with the option ticked, the model gets hard edges (wrong normals), and the blend shapes gets correct per-vertex normals.

2. I am exporting with the “Tangent and Binormals” option. Then, when trying to read back the tangents using the FBX SDK using my own app, I see that the mesh has tangents:

But the shapes doesn’t:

I have exported in ASCII format, and checked with a text editor that the tangent information is there for the shapes. So the problem is that I am unable to read it using the FBX SDK.

Thanks!

Hi,

Since the entire fbx team is on vacation so we will get back to you later on this one, and, obviously, we need some time to investigate it a bit too.
Happy new year!

Eric Feng, Framestore

Happy new your for the team too!

Update for issue 2: I have rechecked with a text editor, I was wrong: the problem is that the tangent information is not exported for the shapes, only for the meshes…

Hi,

We will look into this and give you an answer soon.

Viviane

Viviane Rochon
Maya Data Platform
Autodesk

Any update about that?

I have the same issue with the latest fbx plugin FBX 2011.3.1 Plug-in for Maya 2010.

Whether I export in Ascii or Binary, no C++ code can extract the tangents.

Both pMesh->GetTangents
and pMesh->GetLayer( 0 )->GetTangents() result in NULL.

Interestingly the old problem of the ASCII was fixed, I have the data in the ascii file, it is just not loaded.

LayerElement:  {
Type: “LayerElementBinormal”
TypedIndex: 0
}
LayerElement:  {
Type: “LayerElementTangent”
TypedIndex: 0
}

and

LayerElementNormal: 0 {
Version: 101
Name: “”
MappingInformationType: “ByPolygonVertex”
ReferenceInformationType: “Direct”
Normals: *72 {
a: 0,0,0.999999940395355,0,0,0.999999940395355,0,0,0.999999940395355,0,0,0.999999940395355,0,0.999999940395355,0,0,0.999999940395355,0,0,0.999999940395355,0,0,0.999999940395355,0,0,0,-0.999999940395355,0,0,-0.999999940395355,0,0,-0.999999940395355,0,0,-0.999999940395355,0,-0.999999940395355,0,0,-0.999999940395355,0,0,-0.999999940395355,0,0,-0.999999940395355,0,0.999999940395355,0,0,0.999999940395355,0,0,0.999999940395355,0,0,0.999999940395355,0,0,-0.999999940395355,0,0,-0.999999940395355,0,0,-0.999999940395355,0,0,-0.999999940395355,0,0
}
}
LayerElementBinormal: 0 {
Version: 101
Name: “map1”
MappingInformationType: “ByPolygonVertex”
ReferenceInformationType: “Direct”
Binormals: *72 {
a: -1,0,0,-1,0,0,-1,0,0,-1,0,0,-1,0,0,-1,0,0,-1,0,0,-1,0,0,-1,-0,-0,-1,-0,-0,-1,-0,-0,-1,-0,-0,-1,0,0,-1,0,0,-1,0,0,-1,0,0,0,0,1,0,0,1,0,0,1,0,0,1,0,0,-1,0,0,-1,0,0,-1,0,0,-1
}

So everything is there, just does not load.