So let's create a simple scene, a box with Cd and Alpha attributes with some randomization.

It's works well so far, so I export the geo as fbx to other application(Unity3d or C4D) but the Alpha attribute doesn't works.
I re-import the geo with the file node, and I find the strange attribute named "Alpha2“ holds correct alpha value. And the ”Alpha" attribute gets the wrong value.

Is it a bug or something else I don't know?
I get the same result in H17 and H16.5

I attached the simple scene if you want to test.

So I find the problem. I export the fbx file as ASCII, and I find the Color attribute somehow be compressed.

And the Alpha attribute become User Data, which should be in the a channel of color.
It's quite annoy.

Hi,

This should be fixed in tomorrow's daily build.

Alpha values exported with the Cd attributes were not properly taken into account when indexing the colors, which caused the “compression”. The second Alpha was caused by the alpha attribute being exported as a user attribute.