Node name was overwritten by USDZ model - swift

Question

I'm currently developing an iOS app that uses ARKit and SceneKit for the augmented reality.
I'm having a problem while loading an .usdz model into the scene.
I can load it correctly into the scene, but, when I try to get the node name (in which I loaded the .usdz model) after tapping on it, it returns the .usdz name and not the name I gave to it.
The code I use to load the .usdz model is:
let mdlAsset = MDLAsset(url: urlPath)
mdlAsset.loadTextures()
let asset = mdlAsset.object(at: 0) // extract first object
var assetNode = SCNNode(mdlObject: asset)
assetNode = SCNNode(mdlObject: asset)
assetNode.name = "Node-2"
sceneView.scene.rootNode.addChildNode(assetNode)
To capture the tap on the node, the code is:
#objc func handleTap(recognizer: UITapGestureRecognizer){
let location = recognizer.location(in: sceneView)
let results = sceneView.hitTest(location, options: nil)
guard recognizer.state == .ended else { return }
if results.count > 0 {
let result = results[0] as SCNHitTestResult
let node = result.node
print(node.name)
}
}
As I mentioned before, when I tap on the object it prints
Optional("Sphere_0")
value that can be found in the top right corner, in the model details page.
The correct value that I expected was "Node-2".

Answer 1

The name of your USDZ model isn't overridden. It's the peculiarities of SceneKit hit-testing and scene hierarchy. When you perform a hit-test search, SceneKit looks for SCNGeometry objects (not a main node) along the ray you specify. So, all you need to do, once the hit-test is completed, is to find the corresponding parent nodes.
Try this code:
import SceneKit.ModelIO
class GameViewController: UIViewController {
var sceneView: SCNView!
override func viewDidLoad() {
super.viewDidLoad()
sceneView = (self.view as! SCNView)
let scene = SCNScene(named: "art.scnassets/ship.scn")!
sceneView.scene = SCNScene()
sceneView.backgroundColor = .black
let recog = UITapGestureRecognizer(target: self, action: #selector(tap))
sceneView.addGestureRecognizer(recog)
// ASSET
let mdlAsset = MDLAsset(scnScene: scene)
let asset = mdlAsset.object(at: 0)
let node = SCNNode(mdlObject: asset.children[0])
node.name = "Main-Node-Name" // former "ship"
node.childNodes[0].name = "SubNode-Name" // former "shipMesh"
node.childNodes[0].childNodes[0].name = "Geo-Name" // former "Scrap_MeshShape"
sceneView.scene?.rootNode.addChildNode(node)
}
}
And your hit-testing method:
extension GameViewController {
#objc func tap(recognizer: UITapGestureRecognizer) {
let location = recognizer.location(in: sceneView)
let results = sceneView.hitTest(location)
guard recognizer.state == .ended else { return }
if results.count > 0 {
let result = results[0] as SCNHitTestResult
let node = result.node
print(node.name!) // Geo-Name
print(node.parent!.name!) // SubNode-Name
print(node.parent!.parent!.name!) // Main-Node-Name
}
}
}