title: How to get the screen central position in arkit?
body: <p>I set a beat sight in the middle of the screen, and when I tap the screen and fire a bullet, on the ipad the beat sight and bullet are in the same position as expected, but on iphone (11) the bullet position is above the beat sight.</p>
  <p>on ipad
  <a href="https://i.stack.imgur.com/36h6W.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/36h6W.jpg" alt="enter image description here" /></a>
  on iphone</p>
  <p><a href="https://i.stack.imgur.com/uPEod.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uPEod.jpg" alt="enter image description here" /></a></p>
  <p>The beat sight config is below</p>
  <p><a href="https://i.stack.imgur.com/38j4d.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/38j4d.png" alt="enter image description here" /></a></p>
  <p>And the bullet position is below</p>
  <pre><code>   guard let pointOfView = sceneView.pointOfView else {return}
          let transform = pointOfView.transform
          let orientation = SCNVector3(-transform.m31, -transform.m32, -transform.m33)
          let location = SCNVector3(transform.m41, transform.m42, transform.m43)
          let position = orientation + location
  </code></pre>
  <p>Does anyone know how to solve it? Thanks a lot.</p>