title: Three.js - Updated geometry is not rendering changes
body: <p>I'm having a little issue here. I have a <code>THREE.Line</code> object, with a material and a geometry. The init method pushes 2 vertices to the geometry, add the Line to the scene, the line is rendered just fine.</p>
  
  <p>But I have an event listener... Every click in the canvas will add another vertex. But when the scene is rendered, only the original 2 vertices are rendered. I've output a dump of <code>scene.children</code> and I'm sure that the Line is in the scene, and the geometry has changed.</p>
  
  <p>In the documentation it says something about applying:</p>
  
  <pre><code>geometry.dynamic = true
  geometry.verticesNeedUpdate = true 
  </code></pre>
  
  <p>But these didn't work either.</p>