Hello.
I found that vertex color exported only when vertex alpha not equal zero. But before(when I used with 3DS MAX 2010 and FBX 2010) vertex color was presented even when vertex alpha is zero.

The process looks so:
1. Create a mesh in 3DS MAX 2012 SP1.
2. Coloring vertex color by using VertexPaint modifier.
3. Coloring vertex alpha by using VertexPaint modifier.
(I want to note, it is looks great with my shader in 3DS MAX viewport)
4. Export with FBX Plug-in 2012.2 to fbx file.
5. Render in XNA under my shader with input pre-vertex semantic “COLOR”

If vertex alpha is zero(was painted in black(0,0,0) color in 3DS MAX), then the vertex color painted black in XNA under my shader(although in 3DS MAX it was not painted in black), if vertex alpha was painted in white(255, 255, 255), then it is looks normal, all colors is present, but for multytexturing with four textures I need have vertex color even when vertex alpha of this vertex is zero. It was be possible in 3DS MAX 2010 with FBX Plug-in 2010.

Is it the feature, bug or I just miss some thing?

P.S.
If my question is unclear, just tell me, I’ll try to rephrase.

Thanks.

Hi Carlos!
I did what you asked and looks like FBX and 3DS MAX is unguilty. The FBX file contains a vertex color even when alpha is zero.

Vertex number 3 in triangle with zero alpha:

LayerElementColor: 0 {
Version: 101
Name: “”
MappingInformationType: “ByPolygonVertex”
ReferenceInformationType: “IndexToDirect”
Colors: 1,1,1,1,0,0,1,1,1,1,1,0
ColorIndex: 2,0,1
}

It seems XNA 4.0 pleased us one more bug or maybe it’s one more “nice” new limitation. Looks like I should go and struggle with XNA 4.0 FBX importer.

Anyway I know what should I do now. I’ll post the reason here when I’ll find it.
Thanks!

I was inattentive.
The solution is here:
http://forums.create.msdn.com/forums/p/72254/598627.aspx#598627