title: FBX animations not running properly with three js
body: <p>I am having an issue with animations on some fbx models. If I have, for example an animation that lasts 20 secs, the model will stay still for 19 secs and then all changes will happen within the last second or so. On other fbx models the animation runs correctly. 
  The code that I am using to run the animation is a follows:
  The loader.load callback is:</p>
  
  <pre><code>var clock = new THREE.Clock();
  var mixers = [];
  
  function(object){
          object.position.set(0,0,0);
          object.mixer = new THREE.AnimationMixer(object);
          mixers.push(object.mixer);
          console.log(object);
          for (var a = 0; a &lt; object.animations.length; a++){
              var action = object.mixer.clipAction(object.animations[a]);
              action.play();
              console.log(action);
          }
  
  
  
          scene.add(object);
          animate();
      }
  </code></pre>
  
  <p>And the animate code is:</p>
  
  <pre><code>function animate() {
      requestAnimationFrame(animate);
      for(var i = 0; i &lt; mixers.length; i++){
          mixers[i].update(clock.getDelta());
      }
      render();
      stats.update();
  }
  
  function render() {
      if (mixer) {
          mixer.update(clock.getDelta());
      }
      renderer.render(scene, camera);
  }
  </code></pre>
  
  <p>Any ideas? Thanks!</p>