title: How do I implement a collision at a point?
body: <p>Should I create an invisible <code>SKNode</code> for a user touch? Or can I emulate a collision at a point?</p>
  
  <p>I think I got the proper collision "detection":</p>
  
  <pre><code>CGPoint currentPoint = [((UITouch*)(touches.allObjects.firstObject)) locationInNode:self];
  if([_ball containsPoint:currentPoint])
  {
      [_ball.physicsBody applyImpulse:impulseVector atPoint:currentPoint];
  }
  </code></pre>
  
  <p>This however sometimes results in the "touch" and the sprite to pass through each other. I'm wondering if just creating a <code>SKNode</code> that represents the touch is the expected way to handle this, or if I can handle it by "point" of contact.</p>