title: Confusing issue adding and removing SKPhysicsJointPin upon touch
body: <p>I'm having trouble with adding and removing my SKPhysicsJointPin in the touchesBegan function. The issue is that my joint is declared in the didMoveToView function because it needs to be positioned based on expressions that exists within it.</p>
  
  <p>That being so I can't refer to the SKPhysicsJoint within the touchesBegan function, which is necessary for what I'm trying to do with my project. Any solutions or suggestions?</p>
  
  <p>Code:</p>
  
  <pre><code>import SpriteKit
  
  class GameScene: SKScene, SKPhysicsContactDelegate {
  
      var head = SKSpriteNode(imageNamed: "crown.png")
      var headTexture = SKTexture(imageNamed: "crown.png")
  
      var neck = SKSpriteNode(imageNamed: "throat.png")
      var neckTexture = SKTexture(imageNamed: "throat.png")
  
      override func didMoveToView(view: SKView) {
  
          head.position.x = torso.position.x - 1
          head.position.y = torso.position.y + 77
          head.physicsBody = SKPhysicsBody(texture: headTexture, size: head.size)
          head.physicsBody!.categoryBitMask = ColliderType.part.rawValue
          head.physicsBody!.contactTestBitMask = ColliderType.part.rawValue
          head.physicsBody!.collisionBitMask = ColliderType.part.rawValue
          self.addChild(head)
  
          neck.position.x = torso.position.x
          neck.position.y = torso.position.y + 44
          neck.physicsBody = SKPhysicsBody(texture: neckTexture, size: neck.size)
          neck.physicsBody!.categoryBitMask = ColliderType.mjoint.rawValue
          neck.physicsBody!.contactTestBitMask = ColliderType.mjoint.rawValue
          neck.physicsBody!.collisionBitMask = ColliderType.mjoint.rawValue
          self.addChild(neck)
  
          let headToNeck = SKPhysicsJointPin.jointWithBodyA(head.physicsBody!, bodyB:neck.physicsBody!, anchor:CGPointMake(head.position.x, head.position.y - 20.8))
          headToNeck.shouldEnableLimits = true
          self.physicsWorld.addJoint(headToNeck)
      }
  
      override func touchesBegan(touches: Set&lt;UITouch&gt;, withEvent event: UIEvent?) {
  
          self.physicsWorld.removeJoint(headToNeck)
  
      }
  }
  </code></pre>