# FaceTrackingModule

The `FaceTrackingModule` class enables tracking faces in 3D.

## Example

```
//==============================================================================
// The following example demonstrates how to control the rotation and scale of
// an object using face rotation and mouth openness.
//
// Project setup:
// - Insert a plane
//==============================================================================

// Load in the required modules
const FaceTracking = require('FaceTracking');
const Scene = require('Scene');

// Locate the plane in the Scene
const plane = Scene.root.find('plane0');

// Store a reference to a detected face
const face = FaceTracking.face(0);

//==============================================================================
// Control the rotation of the plane with the rotation of the face
//==============================================================================

// Store references to the transform of the plane and face
const planeTransform = plane.transform;
const faceTransform = face.cameraTransform;

// Bind the rotation of the face to the rotation of the plane
planeTransform.rotationX = faceTransform.rotationX;
planeTransform.rotationY = faceTransform.rotationY;
planeTransform.rotationZ = faceTransform.rotationZ;

//==============================================================================
// Control the scale of the plane with mouth openness
//==============================================================================

// Store a reference to the mouth openness with some additional mathematical
// operations to amplify the signal
const mouthOpenness = face.mouth.openness.mul(4).add(1);

// Bind the mouthOpenness signal to the x and y-axis scale signal of the plane
planeTransform.scaleX = mouthOpenness;
planeTransform.scaleY = mouthOpenness;
```

## Properties

| Property | Description                                                                                                                                                         |
| -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `count`  | <p><code>(get) count: ScalarSignal (set) (Not Available)</code> <br> Returns a <code>ScalarSignal</code> representing the number of faces tracked in the scene.</p> |

## Methods

| Method | Description                                                                                                                                  |
| ------ | -------------------------------------------------------------------------------------------------------------------------------------------- |
| `face` | <p><code>face(index: number): Face</code> <br> Returns the <code>Face</code> object from the detected face array at the specified index.</p> |

## Classes

| Class                                                                                                   | Description                                                      |
| ------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------- |
| [`Cheek`](https://sparkar.facebook.com/docs/ar-studio/reference/classes/facetrackingmodule.cheek)       | The `Cheek` class exposes the details of a detected cheek.       |
| [`Chin`](https://sparkar.facebook.com/docs/ar-studio/reference/classes/facetrackingmodule.chin)         | The `Chin` class exposes the details of a detected chin.         |
| [`Eye`](https://sparkar.facebook.com/docs/ar-studio/reference/classes/facetrackingmodule.eye)           | The `Eye` class exposes the details of a detected eye.           |
| [`Eyebrow`](https://sparkar.facebook.com/docs/ar-studio/reference/classes/facetrackingmodule.eyebrow)   | The `Eyebrow` class exposes the details of a detected eyebrow.   |
| [`Face`](https://sparkar.facebook.com/docs/ar-studio/reference/classes/facetrackingmodule.face)         | The `Face` class exposes details of a tracked face.              |
| [`Forehead`](https://sparkar.facebook.com/docs/ar-studio/reference/classes/facetrackingmodule.forehead) | The `Forehead` class exposes the details of a detected forehead. |
| [`Mouth`](https://sparkar.facebook.com/docs/ar-studio/reference/classes/facetrackingmodule.mouth)       | The `Mouth` class exposes the details of a detected mouth.       |
| [`Nose`](https://sparkar.facebook.com/docs/ar-studio/reference/classes/facetrackingmodule.nose)         | The `Nose` class exposes the details of a detected nose.         |