.swift

 @IBOutlet var sceneView: ARSCNView!
    private var gSession :GARSession!
    private var arAnchor :ARAnchor!
    private var garAnchor :GARAnchor!
    private var rootRef :DatabaseReference!

override func viewDidLoad() {
        super.viewDidLoad()
        
        self.rootRef = Database.database().reference()
        self.sceneView.autoenablesDefaultLighting = true
        
        // enable the arcore session
        self.gSession = try! GARSession(apiKey: "PutYourOwnAPIKeyHere", bundleIdentifier: nil)
        
        // Set the view's delegate
        sceneView.delegate = self
        self.gSession.delegate = self
        self.gSession.delegateQueue = DispatchQueue.main
        
        sceneView.session.delegate = self
        // Create a new scene
        let scene = SCNScene()
        // Set the scene to the view
        sceneView.scene = scene
        
       
    }