App Crashes when accessing component's setter (iOS 13) - ios

Question

I wrote the code base on Apple's example,
somehow the app will crash if accessing the setter of the custom entity component (the reveal() method)
I tried to initialize the component to see what will happen, but it crashed at anchor.addChild(card) (ViewController line 89) instead.
But it runs without any problem on iPadOS 14 which makes it even weirder.
Does anyone know why it happens and how to fix it?
my code
// CardEntity.swift
// Card-Game
//
// Created by Ian Liu on 2020/7/21.
//
import Foundation
import RealityKit
class CardEntity: Entity, HasModel, HasCollision {
required init() {
super.init()
self.components[ModelComponent] = ModelComponent(
mesh: .generateBox(width: 0.09, height: 0.005, depth: 0.09),
materials: [SimpleMaterial(
color: .orange,
isMetallic: false)
]
)
}
var card: CardComponent {
get { components[CardComponent] ?? CardComponent() }
set { components[CardComponent] = newValue }
}
}
extension CardEntity {
func reveal() {
card.revealed = true
var transform = self.transform
transform.rotation = simd_quatf(angle: 0, axis: [1, 0, 0])
move(to: transform, relativeTo: parent, duration: 0.25, timingFunction: .easeInOut)
}
func hide() {
card.revealed = false
var transform = self.transform
transform.rotation = simd_quatf(angle: .pi, axis: [1, 0, 0])
move(to: transform, relativeTo: parent, duration: 0.25, timingFunction: .easeInOut)
}
}
// CardComponent.swift
// Card-Game
//
// Created by Ian Liu on 2020/7/21.
//
import Foundation
import RealityKit
struct CardComponent: Component, Codable {
var revealed = false
var id = -1
init() {
self.revealed = false
self.id = -1
}
}
//
// ViewController.swift
// Card-Game
//
// Created by 劉學逸 on 7/16/20.
//
import UIKit
import ARKit
import RealityKit
import Combine
class ViewController: UIViewController, ARSessionDelegate {
#IBOutlet var arView: ARView!
let cardCount = 16
var prevCard: CardEntity? = nil
override func viewDidLoad() {
super.viewDidLoad()
arView.center = self.view.center
arView.centerXAnchor.constraint(equalTo: self.view.centerXAnchor).isActive = true
arView.centerYAnchor.constraint(equalTo: self.view.centerYAnchor).isActive = true
arView.session.delegate = self
let config = ARWorldTrackingConfiguration()
if ARWorldTrackingConfiguration.supportsFrameSemantics(.personSegmentation) {
config.frameSemantics.insert(.personSegmentationWithDepth)
}
config.planeDetection = [.horizontal]
arView.session.run(config)
addCoachingOverlay()
let anchor = AnchorEntity(plane: .horizontal, minimumBounds: [0.2, 0.2])
arView.scene.addAnchor(anchor)
CardComponent.registerComponent()
var cards: [CardEntity] = []
var models: [Entity] = []
for index in 1...cardCount {
let cardModel = CardEntity()
cardModel.name = "card_\((index+1)/2)"
cardModel.card.id = (index+1)/2
cards.append(cardModel)
}
var cancellable: Cancellable? = nil
// will build for a long time if load 8 models
cancellable = ModelEntity.loadModelAsync(named: "memory_card_1")
.append(ModelEntity.loadModelAsync(named: "memory_card_2"))
.append(ModelEntity.loadModelAsync(named: "memory_card_3"))
.append(ModelEntity.loadModelAsync(named: "memory_card_4"))
.append(ModelEntity.loadModelAsync(named: "memory_card_5"))
.append(ModelEntity.loadModelAsync(named: "memory_card_6"))
.append(ModelEntity.loadModelAsync(named: "memory_card_7"))
.append(ModelEntity.loadModelAsync(named: "memory_card_8"))
.collect().sink(receiveCompletion: {error in
print("error: \(error)")
cancellable?.cancel()},
receiveValue: { entities in
for (index, entity) in entities.enumerated() {
entity.setScale(SIMD3<Float>(0.0025,0.0025,0.0025), relativeTo: anchor)
entity.position = entity.position + SIMD3<Float>(0, 0.0025, 0)
entity.name = "memory_card_\(index)"
for _ in 1...2 {
models.append(entity.clone(recursive: true))
}
}
for (index, card) in cards.enumerated() {
card.addChild(models[index])
}
cards.shuffle()
for card in cards {
var flipTransform = card.transform
flipTransform.rotation = simd_quatf(angle: .pi, axis: [1, 0, 0])
card.move(to: flipTransform, relativeTo: card.parent)
}
//attach cards to the anchor
for (index, card) in cards.enumerated() {
card.generateCollisionShapes(recursive: true)
let x = Float(index % Int(sqrt(Double(self.cardCount)))) - 1.5
let z = Float(index / Int(sqrt(Double(self.cardCount)))) - 1.5
card.position = [x * 0.1, 0, z * 0.1]
anchor.addChild(card)
}
cancellable?.cancel()
})
// Adding Occlusion Box
// Create box mesh, 0.7 meters on all sides
let boxSize: Float = 0.7
let boxMesh = MeshResource.generateBox(size: boxSize)
// Create Occlusion Material
let material = OcclusionMaterial()
// Create ModelEntity using mesh and materials
let occlusionBox = ModelEntity(mesh: boxMesh, materials: [material])
// Position box with top slightly below game board
occlusionBox.position.y = -boxSize / 2 - 0.001
// Add to anchor
anchor.addChild(occlusionBox)
}
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransition(to: size, with: coordinator)
arView.center = view.center
centerCoachingView()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
guard let configuration = arView.session.configuration else { return }
arView.session.run(configuration)
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
arView.session.pause()
}
#IBAction func onTap(_ sender: UITapGestureRecognizer) {
let tapLocation = sender.location(in: arView)
if let entity = arView.entity(at: tapLocation) {
var card = entity
if entity.name.hasPrefix("memory_card") {
card = entity.parent!
}
guard let cardEntity = card as? CardEntity else { return }
print("tapped card id: \(cardEntity.card.id)")
if cardEntity.card.revealed {
return
} else {
cardEntity.reveal()
}
if let lastCard = prevCard {
print("last card id: \(lastCard.card.id)")
if lastCard.card.id != cardEntity.card.id {
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
cardEntity.hide()
lastCard.hide()
}
}
self.prevCard = nil
} else {
print("last card id: N\\A")
prevCard = cardEntity
}
}
}
}
extension ViewController: ARCoachingOverlayViewDelegate {
func addCoachingOverlay() {
let coachingOverlay = ARCoachingOverlayView()
coachingOverlay.autoresizingMask = [.flexibleHeight, .flexibleWidth]
coachingOverlay.center = view.center
coachingOverlay.delegate = self
coachingOverlay.session = arView.session
coachingOverlay.goal = .horizontalPlane
arView.addSubview(coachingOverlay)
NSLayoutConstraint.activate([
coachingOverlay.centerXAnchor.constraint(equalTo: view.centerXAnchor),
coachingOverlay.centerYAnchor.constraint(equalTo: view.centerYAnchor),
coachingOverlay.widthAnchor.constraint(equalTo: view.widthAnchor),
coachingOverlay.heightAnchor.constraint(equalTo: view.heightAnchor)
])
coachingOverlay.activatesAutomatically = true
}
//TODO: Fix coachingView won't center when first orientation change
func centerCoachingView() {
for subview in arView.subviews {
if let coachingView = subview as? ARCoachingOverlayView {
coachingView.center = self.view.center
}
}
}
}