anchor.diff:      rootNode.attachChild(sceneModel);
       bulletAppState.getPhysicsSpace().add(landscape);
       bulletAppState.getPhysicsSpace().add(player);
  +
  +    // You can change the gravity of individual physics objects after they are
  +    // added to the PhysicsSpace.
  +    player.setGravity(new Vector3f(0,-30f,0));
  +
     }
   
     private void setUpLight() {
  
positive.code: ----
  
  .  You set the background color to light blue, since this is a scene with a sky.
  .  You repurpose the default camera control “flyCam as first-person camera and set its speed.
  .  The auxiliary method `setUpLights()` adds your light sources.
  .  The auxiliary method `setUpKeys()` configures input mappings–we will look at it later.
  
  
negative.code: 
  [TIP]
  ====
  "`Does that CollisionShape make me look fat?`" If you ever get confusing physics behaviour, remember to have a look at the collision shapes. Add the following line after the bulletAppState initialization to make the shapes visible:
  
  [source,java]
  ----
  