Anchoring Multiple Scenes in RealityKit - swift

Question

While loading multiple scenes (from reality composer) into arView, the scenes is not anchored in the same space.
In this example, scene1 is loaded when the app starts. After the button is pressed, the scene2 is added into the scene. In both the scenes, the models are placed at the origin and are expected to overlap with scene2 is added into the view. However, the position of scene1 and scene2 is different when they are added into the arView.
import UIKit
import RealityKit
class ViewController: UIViewController {
#IBOutlet var arView: ARView!
#IBOutlet weak var button: UIButton!
var scene1: Experience.Scene1!
var scene2: Experience.Scene2!
override func viewDidLoad() {
super.viewDidLoad()
// Load the "Box" scene from the "Experience" Reality File
scene1 = try! Experience.loadScene1()
scene2 = try! Experience.loadScene2()
// Add the box anchor to the scene
arView.scene.addAnchor(scene1)
}
#IBAction func buttonPressed(_ sender: Any) {
arView.scene.addAnchor(scene2)
}
}
Note: This issues does not happen when both the scenes are added simultaneously.
How to make sure that both the scenes are anchored at the same ARAnchor?

Answer 1

Use the following approach:
let scene01 = try! Cube.loadCube()
let scene02 = try! Ball.loadSphere()
let cubeEntity: Entity = scene01.steelCube!.children[0]
let ballEntity: Entity = scene02.glassBall!.children[0]
// var cubeComponent: ModelComponent = cubeEntity.components[ModelComponent].self!
// var ballComponent: ModelComponent = ballEntity.components[ModelComponent].self!
let anchor = AnchorEntity()
anchor.addChild(cubeEntity)
anchor.addChild(ballEntity)
// scene01.steelCube!.components.set(cubeComponent)
// scene02.glassBall!.components.set(ballComponent)
arView.scene.anchors.append(anchor)