title: Moving cannonJS object in 3D according to its quaternion
body: <p>I would like to achieve a space ship like move on a cannonJS body.
  (Im really a beginner)
  I found some examples but none of them are exactly what I'm looking for.</p>
  
  <p>As i know the correct way to move an object, is to change its velocity.</p>
  
  <p>Here's what I have done here: <a href="http://codepen.io/Tomo0613/pen/xVjqqK" rel="nofollow">http://codepen.io/Tomo0613/pen/xVjqqK</a>  <code>enter code here</code>
  But i definitely have problems with understanding quaternions.</p>
  
  <p>Is there a way to update, the vector of the body according to its quaternion as i rotate it, or that's always related to the world?
  Resulting: when the body is accelerating only on the Z axis, it would always move in the direction, where it's facing.</p>