Light Estimation Example

This section includes an example of detecting environment lighting on the Magic Leap 2 headset.

Simple Example

This script queries estimate data when it is ready, updates the simulated lighting and renders a material with the cubemapped texture.

caution

This feature requires the CAMERA permission to be enabled in your project's Manifest Settings. (Edit > Project Settings > Magic Leap > Manifest Settings)

using UnityEngine;
using UnityEngine.XR.OpenXR;
using UnityEngine.XR.MagicLeap;
using MagicLeap.OpenXR.Features.LightEstimation;

public class LightEstimationSampleCode : MonoBehaviour
{
    private MagicLeapLightEstimationFeature _lightEstimationFeature;

    [SerializeField]
    private Material _skyboxMaterial;

    [SerializeField]
    private Light _directionalLight;

    private Vector3 _estimatedLightDirection = Vector3.zero;
    private Cubemap currentCubeMap;
    
    private bool _permissionGranted;
    private readonly MLPermissions.Callbacks permissionCallbacks = new MLPermissions.Callbacks();

    private void Awake()
    {
        permissionCallbacks.OnPermissionDenied += OnPermissionDenied;
        permissionCallbacks.OnPermissionGranted += OnPermissionGranted;
        permissionCallbacks.OnPermissionDeniedAndDontAskAgain += OnPermissionDenied;
        MLPermissions.RequestPermission(MLPermission.Camera, permissionCallbacks);
    }

    // Start is called before the first frame update
    void Start()
    {
        if (!_permissionGranted)
            return;

        // Obtain the Light Estimation Feature.
        _lightEstimationFeature = OpenXRSettings.Instance.GetFeature<MagicLeapLightEstimationFeature>();

        // Create a variable that contains the resolution of each face on the cubemap and set it to 256x256.
        HDRCubemapFaceResolution cubemapFaceResolution
            = HDRCubemapFaceResolution.Resolution_256x256;

        // Create the light estimation.
        _lightEstimationFeature.CreateLightEstimation(cubemapFaceResolution);
    }

    // Update is called once per frame
    void Update()
    {
        if (!_permissionGranted)
            return;

        if (IsLightEstimationDataReadyToBeObtained())
        {
            // Obtain the light estimation data.
            EstimateData estimateData
                = _lightEstimationFeature.GetLightEstimationEstimateData();

            ProcessEstimateData(estimateData);
        }

        // Make the directional light in the scene point in the correct direction.
        _directionalLight.transform.rotation = Quaternion.Lerp(_directionalLight.transform.rotation,
            Quaternion.LookRotation(_directionalLight.transform.position + _estimatedLightDirection), 0.01f);
    }

    private void ProcessEstimateData(EstimateData estimateData)
    {
        // Create variables for the directional light.
        _estimatedLightDirection = estimateData.DirectionalLight.Direction;
        Color estimatedLightColor = estimateData.DirectionalLight.Color;

        Debug.Log("Estimated Light Direction: " + _estimatedLightDirection.ToString());

        // Set the color of the directional light in the scene.
        _directionalLight.color = estimatedLightColor;

        // Obtain the cubemap data. Learn more about cubemaps here:
        // https://en.wikipedia.org/wiki/Cube_mapping
        Cubemap cubemap = _lightEstimationFeature
            .GetEstimateCubemap(estimateData.CubeMap.Pixels, // You can obtain the pixel data from the cubemap.
                (int)estimateData.CubeMap.FaceDimension);

        // Update our renderer with our cubemap data.
        _skyboxMaterial.SetTexture("_Tex", cubemap);
        RenderSettings.customReflectionTexture = cubemap;

        // Delete the previous cube map to free resources
          if(currentCubeMap !=null){
            Destroy(currentCubeMap);
        }
        // Keep track of the new cubemap
        currentCubeMap = cubemap;
    }

    bool IsLightEstimationDataReadyToBeObtained()
    {
        // In order to obtain light estimation data, you must first ensure that
        // the light estimation feature has been created and that our light
        // estimation data is ready to be obtained.
        if (_lightEstimationFeature.LightEstimationCreated
            && _lightEstimationFeature.CheckEstimationEstimateReadiness())
        {
            return true;
        }
        else return false;
    }

    private void OnDestroy()
    {
        _lightEstimationFeature.DestroyLightEstimation();
    }

    private void OnPermissionDenied(string permission)
    {
        // Logic for permission not granted
        Debug.LogError($"Camera permission denied.");
    }

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