title: Distinguish between finger touch and Apple Pencil touch
body: <p>I'm using SceneKit to render a 3D model on an iPad Pro. My requirement is that I'd like to perform different interactions when using the Apple Pencil.</p>
  
  <p>Is there a way to distinguish between a finger touch and an Apple Pencil touch?</p>
  
  <p>I tried overriding the <code>touchesBegan</code> function and filtering the <code>UITouch</code> in the <code>Set</code> to ignore the ones with type <code>pencil</code>, but that doesn't seem to do anything... </p>
  
  <p>EDIT: I'm more interested in handling these 2 different types of touches (i.e. when the there's a finger touch event, I want to do some action A. If it's pencil, I want to do action B). Which methods do I even override to achieve this segregation?</p>