Hello! I am trying to figure out how to detect a collision, but no matter what I do, it seems to not want to work(Using didBegin). I have used multiple resources to no avail and im so close to banging my head against the wall lol. Im hoping someone can Identify what im doing wrong with it. I'll attach my class for you :) Thank you for any help! // //  GameView.swift //  DogeBall // //  Created by James Biser on 2/21/21. // import UIKit import SpriteKit import SceneKit import QuartzCore import CoreMotion class GameView: UIViewController, SKSceneDelegate, SKPhysicsContactDelegate {          @IBOutlet var gameView: UIView!     @IBOutlet weak var pointsLabel: UILabel!     @IBOutlet weak var livesLeftLabel: UILabel!               let player = SKSpriteNode(imageNamed: "gameElement.png")     let goal = SKSpriteNode(imageNamed: "goal.png")     var motionManager = CMMotionManager()     var destX:CGFloat  = 0.0     var destY : CGFloat = 0.0     @IBOutlet weak var SKGameView: SKView!          var scene = SKScene()     var toggle = true               override func viewDidLoad() {         // self.navigationController?.isNavigationBarHidden = true         scene.size =  gameView.bounds.size         scene.scaleMode = .aspectFill          SKGameView.presentScene(scene)          SKGameView.showsFPS = true          SKGameView.showsNodeCount = true          SKGameView.showsPhysics = true                                        player.position = CGPoint(x: SKGameView.frame.size.width/2, y: SKGameView.frame.size.height/2)          player.physicsBody = SKPhysicsBody(circleOfRadius: player.size.width / 2.0)          player.physicsBody?.affectedByGravity = false          player.physicsBody!.contactTestBitMask = 0          player.physicsBody?.collisionBitMask = 0                  //  goal.position = spawnGoalAtRandom()          goal.physicsBody = SKPhysicsBody(circleOfRadius: goal.size.width / 2.0)         goal.position = CGPoint(x: SKGameView.frame.size.width/2+9, y: SKGameView.frame.size.height/2+9)          goal.physicsBody?.affectedByGravity = false          goal.physicsBody!.contactTestBitMask = 0          goal.physicsBody!.collisionBitMask = 0          goal.physicsBody?.usesPreciseCollisionDetection = true          player.physicsBody?.usesPreciseCollisionDetection = true                   scene.addChild(goal)         scene.addChild(player)          motionManager.startAccelerometerUpdates()                  startAccelerometers()     }     func didBeginContact(contact : SKPhysicsContact){         print("cool")     }          func update(_ currentTime: TimeInterval, for scene: SKScene) {         print("update frame")     }     func spawnGoalAtRandom() - CGPoint{         let height = self.scene.frame.height         let width = self.scene.frame.width         let randomPosition = CGPoint(x: CGFloat(arc4random()).truncatingRemainder(dividingBy: height) - 10 , y: CGFloat(arc4random()).truncatingRemainder(dividingBy: width) - 10)                return randomPosition     }          var isTouched = false          override func touchesBegan(_ touches: SetUITouch, with event: UIEvent?) {         if let touch = touches.first {             if player.contains(touch.location(in: scene)) {                 isTouched = true             }         }     }               override func touchesMoved(_ touches: SetUITouch, with event: UIEvent?) {         if (isTouched == true) {             player.position = (touches.first?.location(in: scene))!         }     }     override func touchesEnded(_ touches: SetUITouch, with event: UIEvent?) {         if isTouched {             isTouched = false         }     }          var timer = Timer()          func startAccelerometers() {        // Make sure the accelerometer hardware is available.        if self.motionManager.isAccelerometerAvailable {           self.motionManager.accelerometerUpdateInterval = 1.0 / 60.0  // 60 Hz           self.motionManager.startAccelerometerUpdates()           // Configure a timer to fetch the data.           self.timer = Timer(fire: Date(), interval: (1.0/60.0),                 repeats: true, block: { (timer) in              // Get the accelerometer data.              if let data = self.motionManager.accelerometerData {                 let x = data.acceleration.x                 let y = data.acceleration.y                 let z = data.acceleration.z                                self.didMove()                 self.update()              }           })           // Add the timer to the current run loop.         RunLoop.current.add(self.timer, forMode: .default)        }     }                func didMove() {                     if motionManager.isAccelerometerAvailable {             // 2             motionManager.accelerometerUpdateInterval = 0.01             motionManager.startAccelerometerUpdates(to: .main) {                 (data, error) in                 guard let data = data, error == nil else {                     return                 }                 // 3                 let currentX = self.player.position.x                 let currentY = self.player.position.y                 self.destX = currentX + CGFloat(data.acceleration.x * 500)                 self.destY = currentY + CGFloat(data.acceleration.y*500)             }         }     }     func update() {         if toggle {             let action = SKAction.moveTo(x: destX, duration: 1)             let action2 = SKAction.moveTo(y: destY, duration: 1)             player.run(action)             player.run(action2)                          if !scene.frame.contains(player.position) {                                  self.player.position = CGPoint(x: SKGameView.frame.size.width/2, y: SKGameView.frame.size.height/2)                                  // self.navigationController?.present(ac, animated: true, completion: nil)             }                          if player.contains(goal) {                 print("work")             }                      }     }      //Never gets called     func didBegin(_ contact: SKPhysicsContact) {          print("asdas")     } }