Tracking expressive face blend shapes (ARKit)

ARKit introduces additional advanced face tracking features available only on iOS devices, including blend shapes. Blend shapes refer to morphing mesh geometries that are commonly used for animating the faces of NPCs (non-player characters) in video games and VR applications. Presently, they are an ARKit-specific feature. ARKit blend shapes provide intricate details of facial expressions as separate features, such as a left or right eye blink, looking down, eyes wide open, cheek puff, cheek squint, jaw left, mouth dimple, and many more. Each feature is given a coefficient on a scale of 0.0 to 1.0. This shape data can be forwarded to the Unity Skinned Mesh Renderer (https://docs.unity3d.com/Manual/class-SkinnedMeshRenderer.html) that is used in character animation. A good explanation and conversation can be found at the following URL: https://www.quora.com/What-is-blendshape-exactly.

Building an animated rig (with bones and a skinned...