title: Libgdx bullet show collision objects
body: <p>Alright so I would like to know why when i run this i cannot see the bullet collision objects <em>Prob. a rookie mistake</em>  </p>
  
  <pre><code>    public static PerspectiveCamera cam;
  static btCollisionWorld collisionWorld;
  DebugDrawer debugDrawer;
  public ModelBatch modelBatch;
  btCollisionConfiguration collisionConfig;
  static btDispatcher dispatcher;
  btBroadphaseInterface broadphase;
  public static btCollisionShape voxelShape;
  public static Model model;
  public static ModelInstance test;
  public static btCollisionShape collisiontest;
  public static btCollisionObject collisiontestobject;
  
  @Override
  public void create () {
      Bullet.init();
      collisionConfig = new btDefaultCollisionConfiguration();
      dispatcher = new btCollisionDispatcher(collisionConfig);
      broadphase = new btDbvtBroadphase();
      collisionWorld = new btCollisionWorld(dispatcher, broadphase, collisionConfig);
  
      cam = new PerspectiveCamera(67, 1280, 720);
      cam.position.set(10f,10f,10f);
      cam.lookAt(0,0,0);
      cam.near = 1f;
      cam.far = 300f;
      cam.update();
  
      modelBatch = new ModelBatch();
  
  
      ModelBuilder modelBuilder = new ModelBuilder();
      model = modelBuilder.createBox(3f, 3f, 3f,
              new Material(ColorAttribute.createDiffuse(Color.BLUE)),
              Usage.Position | Usage.Normal);
  
      test = new ModelInstance(model);
  
      test.transform.setTranslation(0,0,0);
  
      collisiontest = new btBoxShape(new Vector3 (6f,6f,6f));
  
      collisiontestobject = new btCollisionObject();
      collisiontestobject.setCollisionShape(collisiontest);
      collisiontestobject.setWorldTransform(new Matrix4());
  
      debugDrawer = new DebugDrawer();
      debugDrawer.setDebugMode(btIDebugDraw.DebugDrawModes.DBG_MAX_DEBUG_DRAW_MODE);
  
      collisionWorld.setDebugDrawer(debugDrawer);
  
  
  }
  
  @Override
  public void render () {
  
      cam.update();
  
  
      Gdx.gl.glViewport(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
      Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT);
  
  
      debugDrawer.begin(cam);
      collisionWorld.debugDrawWorld();
      debugDrawer.end();
  
      //modelBatch.begin(cam);
      //modelBatch.render(test);
      //modelBatch.end();
  
  
  }
  </code></pre>
  
  <p>When i run this I expected to see the frames of the collision objects but instead I see nothing... <em>This was a test program i created due to having alot of bullet issues..</em></p>