Can't add PhysicsBody to SKSpriteNode (game crashes) - xcode

Question

I've just been playing around with some of the features of XCode/Swift and building a simple game. I'm having difficulty adding a physicsBody to an SKSpriteNode.
I've created a 'Bullet' class and a 'Tank' class (which has an array of 10 'Bullets' as one of its properties).
The sprite property is being assigned properly with a texture. However, the physicsBody is coming back as 'nil'.
class Tank {
var position = CGPoint()
var speed = CGPoint(x: 0, y: 0)
var sprite = SKSpriteNode()
var viewSize = CGPoint() // width, height
var bullets: [Bullet] = []
var bulletNumber = 0
let TOTAL_BULLETS = 10
// ***Tank class constructor
init(playerNum: Int, filename: NSString, tankName: NSString) {
var spaceshipTexture = SKTexture(imageNamed: "Spaceship")
self.sprite = SKSpriteNode(texture: spaceshipTexture, size: spaceshipTexture.size())
self.sprite.physicsBody? = SKPhysicsBody(texture: spaceshipTexture, size: spaceshipTexture.size())
println(self.sprite.physicsBody)
}
// ****Bullet class
class Bullet {
var position = CGPoint(x: -50, y: -50)
var speed = CGPoint(x: 0, y: 0)
var sprite = SKSpriteNode()
var viewSize = CGPoint() // width, height
var isBeingFired = false
init () {
//self.sprite = SKSpriteNode(imageNamed: "Bullet")
var spaceshipTexture = SKTexture(imageNamed: "Spaceship")
self.sprite = SKSpriteNode(texture: spaceshipTexture, size: spaceshipTexture.size())
self.sprite.xScale = 0.04
self.sprite.yScale = 0.04
self.sprite.physicsBody? = SKPhysicsBody(texture: spaceshipTexture, size: spaceshipTexture.size())
self.sprite.physicsBody?.affectedByGravity = false
println(self.sprite.physicsBody)
}
// *** GameScene
class GameScene: SKScene {
var tank1 = Tank(playerNum: 1, filename: "Spaceship", tankName: "Tank1")
let myLabel = SKLabelNode(fontNamed:"Chalkduster")
override func didMoveToView(view: SKView) {
self.addChild(tank1.sprite)
for i in 0 ..< tank1.TOTAL_BULLETS {
self.addChild(tank1.bullets[i].sprite)
}
For simplicity sake, I'm using the same image for both the Tank and the Bullet (just different sizes) to create the SKSpriteNode.
I'm not sure if this would help, but I add an instance of the Tank and all 10 of its bullets as a child to the GameScene.

Answer 1

Your problem is, that you don't add a SKTexture to your SKSpriteNode but an image. If you want to access an SKTexture you need to add it to your node like that:
var spaceshipTexture = SKTexture(imageNamed: "Spaceship")
var sprite = SKSpriteNode(texture: spaceshipTexture, size: spaceshipTexture.size())
Then you will be able to access the texture of your sprite to create your SKPhysicsBody