Answers to similar questions like this and this did not solve the problem.
Assigning a SpriteKit scene to the overlaySKScene
property of a SCNView does nothing: the SpriteKit scene does not appear at all.
Tested on iPhone 7 and on the Simulator.
Running the code below shows a blank white screen.
@IBOutlet weak var sceneView: SCNView!
override func viewDidLoad() {
let skScene = SKScene(size: UIScreen.main.bounds.size)
skScene.backgroundColor = UIColor.black
let node = SKSpriteNode(imageNamed: "AddButton.png")
skScene.addChild(node)
sceneView.overlaySKScene = skScene
sceneView.overlaySKScene!.scaleMode = .resizeFill
sceneView.overlaySKScene?.isHidden = false
}