Resetting ARKit coordinates

Question

I have a simple question. If I wanted to start a game and place the board right in front of me:

gameBoard!.position = SCNVector3(0, 0, -0.6)

This works until I leave the game and come back again. Can I show the game board in exact same position in front of camera or 0.6m in front of me? I might have physically moved to another position.

Answer 1

If you want to reset you ARSession, you have to pause, remove all nodes and rerun your session by resetting tracking and removing anchors.

I made a reset button that does it whenever i want to reset:

@IBAction func reset(_ sender: Any) {

    sceneView.session.pause()
    sceneView.scene.rootNode.enumerateChildNodes { (node, stop) in
        node.removeFromParentNode()
    }
    sceneView.session.run(configuration, options: [.resetTracking, .removeExistingAnchors])
}

Or put it in your session was interrupted function!

Answer 2

This should be possible using the option resetTracking when you call run on your ARSession again.

Example:

if let configuration = sceneView.session.configuration {
    sceneView.session.run(configuration,
                          options: .resetTracking)
}

Answer 3

To reset ARSession in ARKit framework is quite easy:

class ViewController: UIViewController, ARSCNViewDelegate, ARSessionDelegate {

    @IBOutlet var arView: ARSCNView!
    @IBOutlet weak var sessionInfoLabel: UILabel!

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        let configuration = ARWorldTrackingConfiguration()
        configuration.planeDetection = [.horizontal, .vertical]
        arView.session.run(configuration)
        arView.session.delegate = self
    }
    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        arView.session.pause()
    }
    func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
        guard let planeAnchor = anchor as? ARPlaneAnchor else { 
            return 
        }
        let plane = Plane(anchor: planeAnchor, in: arView)
        node.addChildNode(plane)
    }
    func sessionInterruptionEnded(_ session: ARSession) {
        resetSessionTracking()
        sessionInfoLabel.text = "ARSession's interruption has ended" 
    }
    private func resetSessionTracking() {
        let config = ARWorldTrackingConfiguration()
        config.planeDetection = [.vertical, .horizontal]
        arView.scene.rootNode.enumerateChildNodes { (childNode, _) in
            childNode.removeFromParentNode()
        }
        arView.session.run(config, options: [.removeExistingAnchors, 
                                             .resetTracking, ])
    }
}

Hope this helps.