Identifiers for specific facial features, for use with coefficients describing the relative movements of those features.
SDK
- iOS 11.0+
Framework
- ARKit
Declaration
struct BlendShapeLocation
Overview
The blend
dictionary provided by an ARFace
object describes the facial expression of a detected face in terms of the movements of specific facial features. For each key in the dictionary, the corresponding value is a floating point number indicating the current position of that feature relative to its neutral configuration, ranging from 0
(neutral) to 1
(maximum movement).
ARKit provides many blend shape coefficients, resulting in a detailed model of a facial expression; however, you can use as many or as few of the coefficients as you desire to create a visual effect. For example, you might animate a simple cartoon character using only the jaw
, eye
, and eye
coefficients. A professional 3D artist could create a detailed character model rigged for realistic animation using a larger set, or the entire set, of coefficients.
Note
In the naming of blend shape coefficients, the left and right directions are relative to the face. That is, the eye
coefficient refers to the face's right eye. ARKit views running a face-tracking session mirror the camera image, so the face's right eye appears on the right side in the view.