ARKit - Object not placed - ios

Question

I'm trying to build furniture placing AR app using ARKit,
I have got .scn chair and its PNG textures in my project, my app is supposed to detect horizontal plane then when the user taps the object is placed in the position were tapped.
But the object is not placed when I tapped.
ViewController:
import UIKit
import SceneKit
import ARKit
class ViewController: UIViewController {
#IBOutlet weak var sceneView: ARSCNView!
override func viewDidLoad() {
super.viewDidLoad()
addTapGestureToSceneView()
configureLighting()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
setUpSceneView()
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
sceneView.session.pause()
}
func setUpSceneView() {
let configuration = ARWorldTrackingConfiguration()
configuration.planeDetection = .horizontal
sceneView.session.run(configuration)
sceneView.delegate = self
sceneView.debugOptions = [ARSCNDebugOptions.showFeaturePoints]
}
func configureLighting() {
sceneView.autoenablesDefaultLighting = true
sceneView.automaticallyUpdatesLighting = true
}
#objc func addShipToSceneView(withGestureRecognizer recognizer: UIGestureRecognizer) {
let tapLocation = recognizer.location(in: sceneView)
let hitTestResults = sceneView.hitTest(tapLocation, types: .existingPlaneUsingExtent)
guard let hitTestResult = hitTestResults.first else { return }
let translation = hitTestResult.worldTransform.translation
let x = translation.x
let y = translation.y
let z = translation.z
guard let scene = SCNScene(named: "art.scnassets/chair.scn"),
let shipNode = scene.rootNode.childNode(withName: "chair_DIFFUSE", recursively: false)
else {
print("Failed to render")
return
}
shipNode.position = SCNVector3(x,y,z)
sceneView.scene.rootNode.addChildNode(shipNode)
}
func addTapGestureToSceneView() {
let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(ViewController.addShipToSceneView(withGestureRecognizer:)))
sceneView.addGestureRecognizer(tapGestureRecognizer)
}
}
extension float4x4 {
var translation: float3 {
let translation = self.columns.3
return float3(translation.x, translation.y, translation.z)
}
}
extension UIColor {
open class var transparentLightBlue: UIColor {
return UIColor(red: 90/255, green: 200/255, blue: 250/255, alpha: 0.50)
}
}
extension ViewController: ARSCNViewDelegate {
func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
// 1
guard let planeAnchor = anchor as? ARPlaneAnchor else { return }
// 2
let width = CGFloat(planeAnchor.extent.x)
let height = CGFloat(planeAnchor.extent.z)
let plane = SCNPlane(width: width, height: height)
// 3
plane.materials.first?.diffuse.contents = UIColor.transparentLightBlue
// 4
let planeNode = SCNNode(geometry: plane)
// 5
let x = CGFloat(planeAnchor.center.x)
let y = CGFloat(planeAnchor.center.y)
let z = CGFloat(planeAnchor.center.z)
planeNode.position = SCNVector3(x,y,z)
planeNode.eulerAngles.x = -.pi / 2
// 6
node.addChildNode(planeNode)
}
func renderer(_ renderer: SCNSceneRenderer, didUpdate node: SCNNode, for anchor: ARAnchor) {
// 1
guard let planeAnchor = anchor as? ARPlaneAnchor,
let planeNode = node.childNodes.first,
let plane = planeNode.geometry as? SCNPlane
else { return }
// 2
let width = CGFloat(planeAnchor.extent.x)
let height = CGFloat(planeAnchor.extent.z)
plane.width = width
plane.height = height
// 3
let x = CGFloat(planeAnchor.center.x)
let y = CGFloat(planeAnchor.center.y)
let z = CGFloat(planeAnchor.center.z)
planeNode.position = SCNVector3(x, y, z)
}
}
So I get "failed to render" printed when I tap to place the object and nothing else is printed in the console !

Answer 1

So after a little code tweaking I fixed the issue with the following couple lines of code:
// Create a new scene
let scene = SCNScene(named: "art.scnassets/chair.scn")!
let node = scene.rootNode.childNode(withName: "chair", recursively: true)!
node.position = SCNVector3(x,y,z)
scene.rootNode.addChildNode(node)
//shipNode.position = SCNVector3(x,y,z)
sceneView.scene = scene
instead of:
guard let scene = SCNScene(named: "art.scnassets/chair.scn"),
let shipNode = scene.rootNode.childNode(withName: "chair_DIFFUSE", recursively: false)
else {
print("Failed to render")
return
}
shipNode.position = SCNVector3(x,y,z)
sceneView.scene.rootNode.addChildNode(shipNode)