ChangeLog - TrackedPlane Prefab has now been renamed to DetectedPlaneVisualizer and can be found at: GoogleARCore>>Examples>>Common>>Prefabs>>DetectedPlaneVisualizer Use the PlaneVisualizationManager.cs from the ARCore1.2 Folder InstantiatObjectOnTouch.cs Code Changed => GoogleARCore.HelloAR; to GoogleARCore.Examples.HelloAR;

If you are using ARCore 1.1 or 1.0, You will find this at: GoogleARCore>>Examples>>HelloAR>>Prefabs>>TrackedPlaneVisualizer Use the PlaneVisualizationManager.cs from the ARCore1.0_1.1 Folder.