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  "identifier" : "/documentation/ARKit/ARFaceAnchor/BlendShapeLocation/mouthClose",
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  "title" : "mouthClose"
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# mouthClose

The coefficient describing closure of the lips *independent of jaw position*.

```
static let mouthClose: ARFaceAnchor.BlendShapeLocation
```

## Discussion

This coefficient describes a closing of the lips without relation to the position of the jaw (the [`jawOpen`](/documentation/ARKit/ARFaceAnchor/BlendShapeLocation/jawOpen) coefficient), so some values of the [`mouthClose`](/documentation/ARKit/ARFaceAnchor/BlendShapeLocation/mouthClose) coefficient can produce unrealistic facial expressions unless other coefficients are also set to realistic values.

The figure below shows a face geometry (see [`ARSCNFaceGeometry`](/documentation/ARKit/ARSCNFaceGeometry)) in three states:

1. A neutral face (all [`ARFaceAnchor.BlendShapeLocation`](/documentation/ARKit/ARFaceAnchor/BlendShapeLocation) coefficient values at `0.0`, including both [`jawOpen`](/documentation/ARKit/ARFaceAnchor/BlendShapeLocation/jawOpen) and [`mouthClose`](/documentation/ARKit/ARFaceAnchor/BlendShapeLocation/mouthClose))
2. Setting only the [`jawOpen`](/documentation/ARKit/ARFaceAnchor/BlendShapeLocation/jawOpen) coefficient to `1.0`, while keeping all other coefficient values (including [`mouthClose`](/documentation/ARKit/ARFaceAnchor/BlendShapeLocation/mouthClose)) at `0.0`
3. Setting both the [`jawOpen`](/documentation/ARKit/ARFaceAnchor/BlendShapeLocation/jawOpen) and [`mouthClose`](/documentation/ARKit/ARFaceAnchor/BlendShapeLocation/mouthClose) coefficients to `1.0`, while keeping all other coefficient values at `0.0`

![](images/com.apple.arkit/media-2930045@2x.png)

---

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