Program not detecting collision with Physics Body SpriteKit - swift

Question

I have a simple game where meteors are spawned and the player must dodge these meteors. I am trying to detect if the player (rocketship) has collided with the meteor (enemy) with PhysicsBody. However, nothing happens when they collide. The console should print "Crash detected"
Here's my code:
import SpriteKit
import GameplayKit
import UIKit
class GameScene: SKScene, SKPhysicsContactDelegate{
let player = SKSpriteNode(imageNamed: "spaceship")
let stars = SKSpriteNode(imageNamed: "stars")
let meteor = SKSpriteNode(imageNamed: "meteor")
override func didMove(to view: SKView) {
print(frame.size.width)
print(frame.size.height)
stars.position = CGPoint(x:0, y:0)
stars.zPosition = 1
player.physicsBody = SKPhysicsBody(circleOfRadius: player.size.width / 2)
player.position = CGPoint(x:0, y:-320)
player.zPosition = 4
player.physicsBody = SKPhysicsBody()
player.physicsBody?.affectedByGravity = false
player.physicsBody?.isDynamic = false
player.physicsBody?.categoryBitMask = 0
player.physicsBody?.collisionBitMask = 1
player.physicsBody?.contactTestBitMask = 1
self.addChild(player)
self.addChild(stars)
addMeteor()
}
func addMeteor() {
meteor.physicsBody = SKPhysicsBody(circleOfRadius: meteor.size.width / 2)
meteor.physicsBody?.affectedByGravity = false
meteor.setScale(0.50)
meteor.position = CGPoint(x:Int(arc4random()%300),y:Int(arc4random()%600))
//meteor.position = CGPoint(x:0 , y:0)
meteor.zPosition = 4
meteor.physicsBody?.categoryBitMask = 1
meteor.physicsBody?.collisionBitMask = 0
self.addChild(meteor)
}
func fireBullet() {
let bullet = SKSpriteNode(imageNamed: "bullet")
bullet.position = player.position
bullet.setScale(0.5)
bullet.zPosition = 3
self.addChild(bullet)
let moveBullet = SKAction.moveTo(y: self.size.height + bullet.size.height, duration: 1)
let deleteBullet = SKAction.removeFromParent()
let bulletSequence = SKAction.sequence([moveBullet, deleteBullet])
bullet.run(bulletSequence)
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
fireBullet()
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch: AnyObject in touches {
let pointOfTouch = touch.location(in: self)
let previousPointOfTouch = touch.previousLocation(in: self)
let amountDragged = pointOfTouch.x - previousPointOfTouch.x
player.position.x += amountDragged
}
}
func didBegin(_ contact: SKPhysicsContact) {
print("Crash detected")
}
override func update(_ currentTime: TimeInterval) {
meteor.position.y -= 6
if meteor.position.y < player.position.y - 300{
meteor.removeFromParent()
addMeteor()
}
}
}
The program should detect collision and then execute the didBegin function (which prints "Crash detected" to the console). However, when I run the program, the console doesn't have anything printed to it. Anybody know what im doing wrong? Thanks!

Answer 1

in didMove method add this line of code physicsWorld.contactDelegate = self. you set playerCateoryBitmask to 0. that means nothing can hit the player. use player.physicsBody?.categoryBitMask = 2 and also set your meteor a contactTestBitMask like so: meteor.physicsBody?.contactTestBitMask