title: apply force to an object in specefic direction with bullet physics
body: <p>I'm trying to fire cubes from the camera origin, using the cameras direction as the firing line. I would like to be able to alter the amount of power delivered in the shot with an int.</p>
  
  <p>After looking though various bits of code found on the web, the following seems to be what I am looking for.</p>
  
  <pre><code>obj.body.applyCentralImpulse(Vector3);    
  </code></pre>
  
  <p>Where Vector3 giving the forces in the X,Y,Z</p>
  
  <p>The following gives the direction the camera is looking at</p>
  
  <pre><code>Vector3 dir = cam.direction;
  </code></pre>
  
  <p>how can I combine the dir and the required force?</p>
  
  <p>many thanks.</p>