title: How can I provide interactive rotation of an object?
body: <p>In Three.js, there are various Controls, such as TrackballControls, that let the user control the <em>camera</em>. This is great, but I want the user to be able to rotate a part of the scene (e.g. a molecule) without rotating the rest of the scene (e.g. a different molecule, or a light source).</p>
  
  <p>Any suggestions on how to do that?</p>
  
  <p>I wonder, if I supplied a different object to the TrackballControls() constructor instead of the camera... would it just rotate that object?? Seems unlikely...</p>