title: ThreeJS 2D bounding box of 3D object
body: <p>I need figure out the area on screen which my 3D object uses.</p>
  
  <p>I've tried to Google for an answer but with no success.</p>
  
  <p>The function <code>geometry.computeBoundingBox()</code> is only returning the 3D bounding box.</p>
  
  <p>How could I convert this to a 2D bounding box?</p>