I've never made any progress on working out how this is done. For a while I thought it was vertex animation, but when I started looking deeper into Source 2 I saw that there is actually a realtime simulation happening.

Any information on what needs to be exported would be welcome!

I have some questions. What platform are you on? Do you have Blender's bpy.app.debug_value value enabled?

You've got a bone called blender_implicit in your armature. Delete it and the problem will be fixed. I'll fix this properly in the next release.

Yes, but sometimes when importing VTA data that's bad. If I wanted a really accurate match I wouldn't be rounding the values in the first place. :)

The material order depends on entirely on the order of polygons within the mesh. I don't know how you might control that except through retopology.

Why does the material order matter? I've never heard of that before. It might be something worth supporting.

In the meantime try exporting to DMX. It's much easier to re-order polygons there, though you will need to dive into the Datamodel with a script to do so.

It's a trade-off between matching the verts you want and matching the nearby verts you don't. The only good answer is to use DMX instead!

Hmm, I get the same encoding error there. I'll have to look into this before I can start working on this bug.

I can't even get that far in Blender 2.77 as printing anything to the console fails! Which version are you using?

String data in the file needs to be UTF8. Nothing else is supported.

It's not supported but could be done relatively easily using the existing Datamodel module. I'm not sure that I want to venture very far into SFM-specific features though. This might be better as a separate add-on maintained by someone else.