Hand tracking

This page supplements the XR Hands manual and only contains information about APIs where Google's Android XR runtime exhibits platform-specific behavior.

Important

You must ensure to configure the appropriate Permissions to use hand tracking features on Android XR.

Permissions

The XRHandSubsystem in Unity's XR Hands package requires an Android system permission on the Android XR runtime. Your user must grant your app the android.permission.HAND_TRACKING permission before it can receive hand tracking data.

Note

The hand tracking subsystem starts immediately after OpenXR is initialized. Google's Android XR runtime logs an error every frame that the hand tracking subsystem is running and the required permission has not been granted.

Use this example code to request the required permission if it hasn't already been granted:

const string k_Permission = "android.permission.HAND_TRACKING";

#if UNITY_ANDROID
void Start()
{
    if (!Permission.HasUserAuthorizedPermission(k_Permission))
    {
        var callbacks = new PermissionCallbacks();
        callbacks.PermissionDenied += OnPermissionDenied;
        callbacks.PermissionGranted += OnPermissionGranted;

        Permission.RequestUserPermission(k_Permission, callbacks);
    }
}

void OnPermissionDenied(string permission)
{
    // handle denied permission
}

void OnPermissionGranted(string permission)
{
    // handle granted permission
}
#endif // UNITY_ANDROID
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For a code sample that involves multiple permissions in a single request, refer to the Permissions page.