Adding 3D object to ARGeoAnchor

At first you have to check if ARGeoTrackingConfiguration is supported on your device.

Requirements: You need a device with A12+ chip and cellular (GPS) support.

import ARKit

@main class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, 
                       didFinishLaunchingWithOptions launchOptions: 
                                      [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

        if !ARGeoTrackingConfiguration.isSupported {

            let sb = UIStoryboard(name: "Main", bundle: nil)

            window?.rootViewController = sb.instantiateViewController(withIdentifier:
                                                             "unsupportedConfiguration")
        }
        return true
    }
}

…then check whether Geo Tracking is available at your location:

ARGeoTrackingConfiguration.checkAvailability { (available, error) in

    if !available {
        let errorDescription = error?.localizedDescription ?? ""
        let recommendation = "You need a place where geo tracking is supported."
        let restart = UIAlertAction(title: "Restart", style: .default) { (_) in
            self.restartSession()
        }
        self.alertUser(withTitle: "Geo tracking unavailable",
                         message: "\(errorDescription)\n\(recommendation)",
                         actions: [restart])
    }
}

After that supply Info.plist with camera and location permission. Here’s a comprehensive information on Authorization Request for Location Services what includes:

• NSLocationWhenInUseUsageDescription
• NSLocationAlwaysAndWhenInUseUsageDescription
• NSLocationUsageDescription
• NSLocationAlwaysUsageDescription

Only several cities in US, UK, Australia, Canada, Japan and Singapore are supported at the moment…

A list of cities that support ARGeoTrackingConfiguration.

Then you must run Geo Configuration:

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    
    let config = ARGeoTrackingConfiguration()
    sceneView.session.run(config)
}

Then add parametrised anchor to the session:

@IBOutlet var sceneView: ARSCNView!

override func viewDidLoad() {
    super.viewDidLoad()
    sceneView.delegate = self
    sceneView.scene = SCNScene()
    
    let coordinate = CLLocationCoordinate2D(latitude: 40.730610, 
                                           longitude: -73.935242)

    let geoAnchor = ARGeoAnchor(name: "Geo Anchor",
                          coordinate: coordinate,
                            altitude: 33.0)
    
    sceneView.session.add(anchor: geoAnchor)
}

And after that you can add a model with the help of ARGeoAnchor:

extension ViewController: ARSCNViewDelegate {
    
    func renderer(_ renderer: SCNSceneRenderer,
                 didAdd node: SCNNode,
                  for anchor: ARAnchor) {
            
        guard let geoAnchor = anchor as? ARGeoAnchor,
                  geoAnchor.name == "Geo Anchor"
        else { return }
        
        print(geoAnchor.coordinate)
                
        let boxGeometry = SCNBox(width: 1.0,
                                height: 1.0,
                                length: 1.0,
                         chamferRadius: 0.1)

        boxGeometry.firstMaterial?.diffuse.contents = UIColor.red

        let cube = SCNNode(geometry: boxGeometry)
        
        node.addChildNode(cube)
    }
}

P.S.

If you’re interested in how a similar feature works in ARCore, read my post about Geospatial API.