## Image Tracking — Also available on the asset store [here](https://assetstore.unity.com/packages/templates/ar-foundation-demos-image-tracking-164880)
A sample app showing off how to use Image Tracking to track multiple unique images and spawn unique prefabs for each image.
The script [`ImageTrackingObjectManager.cs`](https://github.com/Unity-Technologies/arfoundation-demos/blob/master/Assets/ImageTracking/Scripts/ImageTrackingObjectManager.cs). handles storing prefabs and updating them based on found images. It links into the `ARTrackedImageManager.trackedImagesChanged` callback to spawn prefabs for each tracked image, update their position, show a visual on the prefab depending on it's tracked state and destroy it if removed.
The script [`DistanceManager.cs`](https://github.com/Unity-Technologies/arfoundation-demos/blob/master/Assets/ImageTracking/Scripts/DistanceManager.cs) checks the distances between the tracked images and displays an additional 3D model between them when they reach a [certain proximity.](https://github.com/Unity-Technologies/arfoundation-demos/blob/master/Assets/ImageTracking/Scripts/DistanceManager.cs#L40)
the script [`NumberManager.cs`](https://github.com/Unity-Technologies/arfoundation-demos/blob/master/Assets/ImageTracking/Scripts/NumberManager.cs) handles setting up a [`contraint`](https://docs.unity3d.com/Manual/Constraints.html) (in this case used to billboard the model) on the 3D number objects and provides a function to enable and disabling the rendering of the 3D model.
If you import the image tracking package or download it from the asset store **without** the Onboarding UX there will be a Missing Prefab in your scene. This prefab is a configured [ScreenSpaceUI prefab](https://github.com/Unity-Technologies/arfoundation-demos/blob/master/Assets/UX/Prefabs/ScreenspaceUI.prefab) from the Onboarding UX. It is configured with the UI for finding an image with the goal of finding an image.
A common two step UI / Goal is to instruct the user to find a plane. Once a plane is found you can instruct the user to tap in order to place an object. Once an object is placed fade out the UI.
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