title: three.js loaded model is disappearing while switch to FirstPerson control from Orbitcontrol
body: <p>am having an option to switch Orbit control to FirstPerson control, but while switch my model is disappearing from the scene</p>
  
  <p>my code is below</p>
  
  <pre><code>controls = new THREE.FirstPersonControls( camera ); 
  controls.movementSpeed = 70;
  controls.lookSpeed = 0.04;
  controls.noFly = true;
  controls.lookVertical = false;
  </code></pre>
  
  <p>i need that switch from one control to another the object should be fixed on the position at present  </p>