How can I convert the code below to let me scan in multiple objects with different .sks files for each?

I am creating an augmented reality application that detects 3D objects in space and has a label pop up above them. The current code lets me detect multiple object, but only lets one type of label (.sks file) pop up. I would like to be able to detect multiple objects each with a different label popping up above them.

import UIKit
import SceneKit
import ARKit

class ViewController: UIViewController, ARSCNViewDelegate {

    @IBOutlet var sceneView: ARSCNView!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Set the view's delegate
        sceneView.delegate = self

        // Show statistics such as fps and timing information
        sceneView.showsStatistics = true

        // Create a new scene
        let scene = SCNScene()

        // Set the scene to the view
        sceneView.scene = scene
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        // Create a session configuration
        let configuration = ARWorldTrackingConfiguration()

        // Object Detection
        configuration.detectionObjects = ARReferenceObject.referenceObjects(inGroupNamed: "FlowerObjects", bundle: Bundle.main)!

        // Run the view's session
        sceneView.session.run(configuration)
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)

        // Pause the view's session
        //sceneView.session.pause()
    }

    // MARK: - ARSCNViewDelegate

    func renderer(_ renderer: SCNSceneRenderer, nodeFor anchor: ARAnchor) -> SCNNode? {

        let node = SCNNode()

        if let objectAnchor = anchor as? ARObjectAnchor {
            let plane = SCNPlane(width: CGFloat(objectAnchor.referenceObject.extent.x * 1.0), height: CGFloat(objectAnchor.referenceObject.extent.y * 0.7))

            plane.cornerRadius = plane.width / 8

            let spriteKitScene = SKScene(fileNamed: "ProductInfo")

            plane.firstMaterial?.diffuse.contents = spriteKitScene
            plane.firstMaterial?.isDoubleSided = true
            plane.firstMaterial?.diffuse.contentsTransform = SCNMatrix4Translate(SCNMatrix4MakeScale(1, -1, 1), 0, 1, 0)

            let planeNode = SCNNode(geometry: plane)
            planeNode.position = SCNVector3Make(objectAnchor.referenceObject.center.x, objectAnchor.referenceObject.center.y + 0.5, objectAnchor.referenceObject.center.z) //y was 0.25

            node.addChildNode(planeNode)

        }

        return node
    }


    func session(_ session: ARSession, didFailWithError error: Error) {
        // Present an error message to the user

    }

    func sessionWasInterrupted(_ session: ARSession) {
        // Inform the user that the session has been interrupted, for example, by presenting an overlay

    }

    func sessionInterruptionEnded(_ session: ARSession) {
        // Reset tracking and/or remove existing anchors if consistent tracking is required

    }
}

Solution

An ARReferenceObject has a name variable of type String which is simply:

A descriptive name for the reference object.

When your add an ARReferenceObject to your Assets.xcassetts folder you have the option to set the name (which does actually get set automatically):

As such you can use this property name to handle what to show depending on the ARReferenceObject detected. Personally, I would use the following delegate callback to add content although this is up to you:

func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor)

As such a working example might look something like the following:

//-------------------------
//MARK: - ARSCNViewDelegate
//-------------------------

extension ViewController: ARSCNViewDelegate{

  func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {

    /*
     Check To See Whether AN ARObject Anhcor Has Been Detected
     Get The The Associated ARReferenceObject
     Get The Name Of The ARReferenceObject
     */
    guard let objectAnchor = anchor as? ARObjectAnchor else { return }

    let detectedObject = objectAnchor.referenceObject
    guard let detectedObjectName = detectedObject.name else { return }

    //Get The Extent & Center Of The ARReferenceObject
    let detectedObjectExtent = detectedObject.extent
    let detectedObjecCenter = detectedObject.center

    //Log The Data
    print("""
      An ARReferenceObject Named \(detectedObjectName) Has Been Detected
      The Extent Of The Object Is \(detectedObjectExtent)
      The Center Of The Object Is \(detectedObjecCenter)
      """)

    //Create A Different Scene For Each Detected Object
    node.addChildNode(createSKSceneForReferenceObject(detectedObject: detectedObject))
  }

  /// Creates A Unique SKScene Based On A Detected ARReferenceObject
  ///
  /// - Parameter detectedObject: ARReferenceObject
  /// - Returns: SCNNode
  func createSKSceneForReferenceObject(detectedObject: ARReferenceObject) -> SCNNode{

    let plane = SCNPlane(width: CGFloat(detectedObject.extent.x * 1.0),
                         height: CGFloat(detectedObject.extent.y * 0.7))

    plane.cornerRadius = plane.width / 8

    guard let validName = detectedObject.name else { return SCNNode() }

    let spriteKitScene = SKScene(fileNamed: validName)

    plane.firstMaterial?.diffuse.contents = spriteKitScene
    plane.firstMaterial?.isDoubleSided = true
    plane.firstMaterial?.diffuse.contentsTransform = SCNMatrix4Translate(SCNMatrix4MakeScale(1, -1, 1), 0, 1, 0)

    let planeNode = SCNNode(geometry: plane)
    planeNode.position = SCNVector3Make(detectedObject.center.x, detectedObject.center.y + 0.5, detectedObject.center.z)

    return planeNode
  }
}

All the code is fully commented so it should make sense, and you will notice that I created a reusable function to generate different SKScenes, which of course could be modified to add different content e.g. SCNScene's, SCNNodes etc.

I am using the name of the ARReferenceObject to load a scene of the same name, but you could use an if/else or switch statement depending on what you need.

Hope it helps... Hope it points you in the right direction.