title: Why won't my SKSpriteNodes appear in the scene?
body: <p>I am trying to add a couple of nodes to the scene. When I run the app I just have the default gray background. Neither of the nodes appear in the scene. Here is what I have:</p>
  
  <pre><code>class GameScene: SKScene {
      override func didMoveToView(view: SKView) {
          /* Setup your scene here */
  
          let jumper = SKSpriteNode(imageNamed:"Jumper")
          jumper.xScale = 0.25
          jumper.yScale = 0.25
          jumper.position = CGPointMake(50, 300)
  
          self.addChild(jumper)
  
          let blob = SKSpriteNode(imageNamed:"Blob")
          blob.position = CGPointMake(160, 30)
          blob.xScale = 0.5
          blob.yScale = 0.25
  
          self.addChild(blob)
      }
  </code></pre>
  
  <p>I have checked the image titles and everything is correct there.</p>