title: Why position.y returns me wrong value?
body: <p>I want implement a simple animation, filling from bottom to top. For this I do:</p>
  
  <pre><code>let waterView = UIView(frame: CGRectMake(0, 0, UIScreen.mainScreen().bounds.width, 568))
  
  override func viewDidLoad() {
      super.viewDidLoad()
      print(waterView.layer.position.y)
      self.waterView.backgroundColor = UIColor(red: 50/255, green: 145/255, blue: 248/255, alpha: 1)
      self.view.addSubview(self.waterView)
  }
  
  override func viewDidAppear(animated: Bool) {
      UIView.animateWithDuration(3.0, animations: {
          print(self.waterView.layer.position.y)
      })
  }
  </code></pre>
  
  <p>And when I print it's <code>position.y</code> value, it returns me <strong>284</strong>! I do not understand why??? Why it doesn't return me <strong>0</strong>?</p>
  
  <p>Is there any logic explanation?</p>