title: What effect does camera.up have in Three.js?
body: <p>I'm confused what effect changing the <code>camera.up</code> vector has in three.js.</p>
  
  <p>In this <a href="http://jsfiddle.net/jvanderdoes/zscjccLs/" rel="nofollow">jsfiddle</a>, I have <code>camera.up = new THREE.Vector3(0, 0, 1);</code>, but it doesn't look any different then the default y up vector. What <em>does</em> camera.up do?</p>