Adding 3D object to ARGeoAnchor - swift

Question

Please forgive me if this question is not that great. I've hit a bit of a road block on Apple's documentation of ARGeoAnchor.
Currently ARGeoAnchor just shows a blue dot in the AR Scene View. I'm trying to show any 3d rendereing or object instead.
My code:
let coordinate = CLLocationCoordinate2D(latitude: lat, longitude: lng)
let geoAnchor = ARGeoAnchor(name: "Point 1", coordinate: coordinate)
let boxGeometry = SCNBox(width: 0.1, height: 0.1, length: 0.1, chamferRadius: 0)
let cube = SCNNode(geometry: boxGeometry)
geoAnchor.scene.rootNode.addChildNode(cube)
self.addGeoAnchor(geoAnchor)
The error i'm getting: Value of type 'ARGeoAnchor' has no member 'scene'
I have multiple ARGeoAnchors, they are all currently showing blue dots. How do I get them to show custom 3d objects instead?
Thanks for taking a look!

Answer 1

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.