title: Three.js - Raycaster doesn't work properly on Ipad
body: <p>i had some issues with Raycaster when i tested my code on mobile device. I realised the same problem appears on the official examples on threejs.org when you activate tactile touch( ex: <a href="https://threejs.org/examples/?q=inter#webgl_interactive_cubes" rel="nofollow noreferrer">https://threejs.org/examples/?q=inter#webgl_interactive_cubes</a> ). 
  Is there an alternative to Raycaster to interact with objects in threejs ? </p>
  
  <p>I am using Firefox 58.0.2 (64 bits) to test my three.js project and to simulate tactile touch.</p>
  
  <p>Thanks in advance</p>