How to export arkit blendshapes weights

I want to export 52 arkit blendshapes(not mark 46 blendshapes) weights as json file.
what should I do?

Hello @user119975! Welcome to the community! I informed the dev team of your question. I will post here when I hear back!

Hi @user119975 ,
Our blendshape solve is based on the number of blendshapes available on the target.
In your case, if you need 52 arkit blendshape animated weights on the json, if you have a mesh with those blendshapes that matches the topology of your target head, then the json would contain those 52 animated values.


  • first do Character Transfer from Mark to your target head.
  • next, set the Input Anim Mesh on the BLENDSHAPE CONVERTION panel to the result of the character transfer, and set the Blendshape Mesh to your mesh with those 52 shapes,
  • then run the Setup Blendshape Solve.


Hope it helps.


So if we wanted a 52 arkit outcome in terms of exporting blendshapes. ?
We would do a Character Transfer - not from Mark - but from an Arkit compatible USD?
And then do a Blendshape Generation from the result?

Hi, we need to make clear distinction between blendshape solve and the blendshape generation.

If you want to get 52 arkit shapes on your custom mesh using blendshape generation, that’s not supported at the moment - you can only generate 46 blendshapes from our template.

If you want 52 blendshape weights of an a2f animation using blendshape solve, you can do it by following the instruction of Edy above.

Does it help your question?

Thanks so much for the quick reply. However the problem I have is a bit of a loop :-) Though you may have a suggestion.
The reason I need Audio2face is so that I can apply the correct blendshapes to the UnrealLiveLink Face App streaming into Houdini. And so my custom mesh of a modelled head which has no Blendshapes, is hoping to inheret the Arkit ones in A2F. The only online example I found was this nasty thing which seems to fail in A2F for a variety of reasons. Dropbox - FaceCap_from_IPhoneX_POLYWINK.fbx - Simplify your life

Do you know of an intermediate Arkit USD I could use to at least get the data passed through Mark?

Kind regards,

I’m a bit confused, so what you need is

  • 52 blendshape poses on your custom mesh that will be driven by live link face app?
  • blendshape weights? you want to get the blendshape weights from Audio2Face? or from the LiveLink face app?

The Arkit poses (and so applied / solved blendshapes) from A2F.

Inputs: - Head A with no existing blendshapes
- Mark + MarkMouthOpen
- An Arkit Head B (which has been solved (mesh fitted?) to have the same overall shape as Mark?

Output: Head A with Arkit blenshapes applied (and no weight animation needed),

Hi again, yeah that is not supported with current A2F.
Like I mentioned, you can only transfer 46 shapes on your custom face from the Mark template.
Transferring 3rd-party blendshape poses on your custom face is not supported.

No worries - I’ll try to do a conversion in Houdini from the 52 animated weights into the 42 scheme.
I imagine you’ll get some real interest when you do apply the [ARKit Mark] template options though. Pretty popular!
You’ll be pulling alot of people away from FaceWare Studio and Polywink

Thank you for the suggestion! We will discuss this internally.