ARFoundation Simple Re-Localization using only Tracked Images

relocalize.cs

// A simple way to create persistent AR experiences just from a single (or more) tracked image alone.
// After the image is found, ARFoundation SLAM works it's magic for position tracking.
// To use: Create your scene in Unity as you would for a normal project and place one or more objects corresponding to the sync point.
// This presumes you have a scene with objects in Unity space corresponding to where they would appear physically.
// Make sure that the objects in Unity space corresponding to the image targets has the same pose as it would in physical space.
// Requires an ARTrackedImageManagerComponent
private void OnTrackedImagesChanged(ARTrackedImagesChangedEventArgs imageEventArgs)
{
    foreach (var updatedImage in imageEventArgs.updated)
    {
        switch (updatedImage.trackingState)
        {
            case TrackingState.Tracking:
                // Grab the name and pose of the Tracked Image from the AR Session.
                var imageName = updatedImage.referenceImage.name;
                var imagePosition = updatedImage.transform.position;
                var imageRotation = updatedImage.transform.localRotation * Quaternion.AngleAxis(90, Vector3.right) * Quaternion.AngleAxis(180, Vector3.up);

                // Find the corresponding Game Object (which should have the approximate pose as the Tracked Image)
                var syncObject = GameObject.Find(imageName);
                if (syncObject)
                {
                    // Re-Orient the AR Session / Camera to look at the object in Unity space with the same pose as the Tracked Image in physical space.
                    m_ARSessionOrigin.MakeContentAppearAt(syncObject.transform, imagePosition, imageRotation);
                    return;
                }

                break;
        }
    }
}