title: Scaling of SkSpriteNodes with SpriteKit
body: <p>im a game i am developing i have various nodes that zoom.</p>
  
  <p>depending on the device (ipad/iphone) they have a maximum size between 50-128 (output of <code>println("\(size)")</code>), so i asume the maximal size should be 3x128, right?</p>
  
  <p>when zooming the following happens:</p>
  
  <ul>
  <li>initial size (0,0)</li>
  <li>final size (max,max) -- these are the sizes mentioned above</li>
  </ul>
  
  <p>i am zooming with an SKAction like so:</p>
  
  <pre><code>let imageName = NameGenerator.defaultGenerator.generateAssetName(properties: properties)
  let texture = SKTexture(imageNamed: imageName)
  let node = SKSpriteNode(texture: texture)
  
  let initialSize = CGSizeMake(1, 1)
  let scaleFactor = max / initialSize.width
  let actionScale = SKAction.scaleTo(scale, duration: duration)
  
  node.runAction(scale)
  </code></pre>
  
  <p>so far so good. the app runs smoothly and everything works, <strong>but</strong></p>
  
  <ul>
  <li>nodes are highly pixelated during the scaling animation</li>
  </ul>
  
  <p>my assets are currently only stored in <code>@3x</code> size at <code>300x300px</code></p>
  
  <p><strong>question</strong></p>
  
  <ul>
  <li>what is the optimal texture format (png, svg,...) - is there a way to use vector images?</li>
  <li>what do you think is the optimal texture size for this szenario?</li>
  <li>am i doing the scaling / initialization right or should i do something different to avoid pixelation?</li>
  </ul>