title: three js sphere device controls limit camera rotation
body: <p>using three js to create a sphere and adding a 360 deg picture inside. 
  now, the photo has a black hole at the bottom.</p>
  
  <p>is there a way to limit camera rotation and prevent user from seeing the very bottom of the sphere?</p>
  
  <p>I have this for camera: </p>
  
  <pre><code>this.controls = new THREE.DeviceOrientationControls(this.camera, true);
  </code></pre>
  
  <ul>
  <li>also looking for a solution while using OrbitControls.</li>
  </ul>
  
  <p><code>this.controls = new THREE.OrbitControls(this.camera, this.element);</code></p>
  
  <p>target devices: mobiles support webgl. </p>