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Version: 21 Aug 2024

Magic Leap Eye Tracking Data

To obtain Magic Leap device specific features such as checking the eye tracking FixationConfidence status or if the user is blinking use Magic Leap's InputSubsystem.Extensions

note

If your Application collects, stores, transfers or otherwise uses data off the Magic Leap 2 device that is received via this API, then you must comply with the Magic Leap 2 Eye Tracking Data Transparency Policy.

Below is a list of some of the data that can be obtained via the EyeTrackingState.

  • Fixation Confidence
  • Left/Right Blink
  • Left/Right CenterConfidence
  • Timestamp

Fixation Confidence Example​

This example shows how to obtain the Eye Tracking State from Magic Leap's Eye Tracking XR Device.

caution

This features requires the EYE_TRACKING permission to be requested at runtime and enabled in your project's Manifest Settings (Edit > Project Settings > Magic Leap > Manifest Settings).

 ...
 //A cached version of the located Eye Tracking Input Device
 private InputDevice eyesDevice;
 
    void Start(){
      InputSubsystem.Extensions.MLEyes.StartTracking();
    }

    void Update()
    {
        if (!eyesDevice.isValid)
        {
            //Locate the input device using the FindMagicLeapDevice Util
            this.eyesDevice = InputSubsystem.Utils.FindMagicLeapDevice(InputDeviceCharacteristics.EyeTracking | InputDeviceCharacteristics.TrackedDevice);
            return;
        }
        //Query for Eye Tracking State data
        InputSubsystem.Extensions.TryGetEyeTrackingState(eyesDevice, out MLEyes.State trackingState);
        Debug.Log("Fixation Confidence: " + trackingState.FixationConfidence);
        //Access the trackingState data
        if (trackingState.RightBlink)
        {
           Debug.Log("Right Eye Blink: " + trackingState.RightBlink);
        }
    }
 ...

Eye Width Max Example​

This example shows how to obtain the maximum value for the height and width of the eye_left and eye_right vector as well as the location of the 3D vergence point, intersection of 3D gaze vectors.

caution

This features requires the EYE_TRACKING permission to be requested at runtime and enabled in your project's Manifest Settings (Edit > Project Settings > Magic Leap > Manifest Settings).


using UnityEngine;
using UnityEngine.UI;
using UnityEngine.XR.MagicLeap;

public class GazeRecognitionTest : MonoBehaviour
{
    // Was EyeTracking permission granted by user
    private bool permissionGranted = false;
    private readonly MLPermissions.Callbacks permissionCallbacks = new MLPermissions.Callbacks();

    private void Awake()
    {
        permissionCallbacks.OnPermissionGranted += OnPermissionGranted;
        permissionCallbacks.OnPermissionDenied += OnPermissionDenied;
        permissionCallbacks.OnPermissionDeniedAndDontAskAgain += OnPermissionDenied;

        MLPermissions.RequestPermission(MLPermission.EyeTracking, permissionCallbacks);
    }

    private void OnDestroy()
    {
        permissionCallbacks.OnPermissionGranted -= OnPermissionGranted;
        permissionCallbacks.OnPermissionDenied -= OnPermissionDenied;
        permissionCallbacks.OnPermissionDeniedAndDontAskAgain -= OnPermissionDenied;
    }

    private void Update()
    {
        if (!permissionGranted)
        {
            return;
        }

        MLResult gazeStateResult = MLGazeRecognition.GetState(out MLGazeRecognition.State state);
        MLResult gazeStaticDataResult = MLGazeRecognition.GetStaticData(out MLGazeRecognition.StaticData data);

        Debug.Log($"MLGazeRecognitionStaticData {gazeStaticDataResult.Result}\n" +
            $"Vergence {data.Vergence}\n" +
            $"EyeHeightMax {data.EyeHeightMax}\n" +
            $"EyeWidthMax {data.EyeWidthMax}\n" +
            $"MLGazeRecognitionState: {gazeStateResult.Result}\n" +
            state.ToString());
    }

    private void OnPermissionDenied(string permission)
    {
        MLPluginLog.Error($"{permission} denied, test won't function.");
    }

    private void OnPermissionGranted(string permission)
    {
        permissionGranted = true;
    }
}

See also​