I am working with ARKit Blendshapes. There are 54 or so Blendshapes but when I request the index for a particular Blendshapes I get an error (GetBlendShapeIndex) on the following - mouthOpen, mouthSmile, eyesClosed, eyesLookUp, eyesLookDown.
In Your ARKit doc these are listed as “Additional” blend shapes. Not sure why? And some Blendshapes - I get an index but the avatar does not seem to do anything. Is there a document that covers this?