title: What is the best way to hide a CALayer (without animation)?
body: <p>I have a number of full screen CALayers as part of a single UIView. Depending on how the user interacts with the view, I need to show one layer and hide all others. I'm currently doing this by changing the opacity, i.e. </p>
  
  <p>Layer to hide: [layer setOpacity:0];
  Layer to show: [layer setOpacity:1];</p>
  
  <p>For a reason I don't quite understand, this seems to create a flashing effect on the screen. Partially to avoid this, but also because I have the impression that opacity changes can affect performances, I'm wondering if changing opacity is actually the best way to hide and/or show CALayers, e.g. should I consider changing the zPosition or changing its position so that it no longer appears on screen.</p>
  
  <p>I don't want to animate the transition by the way.</p>
  
  <p>Thanks in advance for any pointers or help.</p>