title: Three.js canvas particles don't render with OrthographicCamera
body: <p>If I take the Three.js <a href="http://mrdoob.github.com/three.js/examples/canvas_lines.html" rel="nofollow noreferrer">canvas_lines demo</a> and replace the perspective camera with an orthographic one:</p>
  
  <pre><code>-    camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 1, 10000 );
  +    camera = new THREE.OrthographicCamera(-window.innerWidth/2, window.innerWidth/2, -window.innerHeight/2, window.innerHeight/2, -100, 10000);
  </code></pre>
  
  <p>it causes the particles to no longer render, though the lines show up.  Is this a bug in Three.js or in my understanding of orthographic projections?</p>
  
  <p>Image of the particles before the change:
  <img src="https://i.stack.imgur.com/xVYPQ.png" alt="enter image description here"></p>
  
  <p>And after the switch to <code>OrthographicCamera</code>:
  <img src="https://i.stack.imgur.com/Q3yuq.png" alt="enter image description here">
  (notice the particles missing and lines terminating in empty space)</p>