title: Change center point of Object3D in Three.js?
body: <p>I am dynamically adding meshes to an <code>Object3D</code> and was wondering if it was possible to get the center of the object such that I can do rotations and on translations equally on the whole mesh and not 'centered' on one end. I know you can access the geometry property of <code>Mesh</code> but I couldn't find an equivalent for <code>Object3D</code>.</p>
  
  <p>Thanks!</p>