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Version: 14 Oct 2024

Generic Eye Tracking Data

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.

Unity Input System can be used to obtain common eye tracking input such as the user's Fixation Point. This section includes a few examples of accessing eye tracking data through the EyesAction class.

See Unity's UnityEngine.InputSystem.XR.Eyes API section for information on all the type of data that can be obtained.

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).

Fixation Point Example​

The following example shows how to Initialize, access and dispose of eye tracking input data.

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

public class EyeTrackingExample: MonoBehaviour
{
    // Used to get Magic Leap Inputs.
    private MagicLeapInputs mlInputs;
    // Used to access eyes action data.
    private MagicLeapInputs.EyesActions eyesActions;
      
    // Start is called before the first frame update
    void Start()
    {
        // Initialize Magic Leap Eye Tracking
        InputSubsystem.Extensions.MLEyes.StartTracking();

        // Initialize Magic Leap inputs to capture input data
        mlInputs = new MagicLeapInputs();
        mlInputs.Enable();
        
        // Initialize Eyes Actions using mlInputs
        eyesActions = new MagicLeapInputs.EyesActions(mlInputs);
    }
    
    void Update()
    {
        // Read the current value of the action.
        var eyes = eyesActions.Data.ReadValue<UnityEngine.InputSystem.XR.Eyes>();
        // Now you can access to the eye input values
        Debug.Log(eyes.fixationPoint);
    }
    
    private void OnDestroy()
    {
        mlInputs.Dispose();
    }
}

Gaze Ray Example​

The example snippet below can be used to debug a green ray from the user's eyes to the fixation point.

    private GameObject fixationPoint;
...
    void Update()
    {
        // Read the current value of the action.
        var eyes = eyesActions.Data.ReadValue<UnityEngine.InputSystem.XR.Eyes>();
        
        //Fixation Gaze Ray
        Vector3 worldPosition = CameraCache.Main.transform.position;
        Vector3 worldRotation = (eyes.fixationPoint - worldPosition).normalized;
        Debug.DrawRay(worldPosition, worldRotation, Color.green);

        //Create a primitive cube to represent the fixation point
        if(fixationPoint == null){
          fixationPoint = GameObject.CreatePrimitive(PrimitiveType.Cube);
          //Render the cube with the default URP shader
          fixationPoint.AddComponent<Renderer>();
          fixationPoint.GetComponent<Renderer>().material = new Material(Shader.Find("Universal Render Pipeline/Lit"));
          fixationPoint.transform.localScale = new Vector3(0.025f,0.025f,0.025f);
        }

        // Position the GameObject to the fixation point
        fixationPoint.transform.position = eyes.fixationPoint;

     }
 ...

See also​