@Override
  public void onPopulateScene(Scene pScene, OnPopulateSceneCallback pOnPopulateSceneCallback) {

    mPhysicsWorld =
        new FixedStepPhysicsWorld(
            60, new Vector2(0f, -SensorManager.GRAVITY_EARTH * 2), false, 8, 3);
    mScene.registerUpdateHandler(mPhysicsWorld);
    final FixtureDef WALL_FIXTURE_DEF = PhysicsFactory.createFixtureDef(0, 0.5f, 0.5f);
    final Rectangle ground =
        new Rectangle(
            cameraWidth / 2f, 6f, cameraWidth - 4f, 8f, this.getVertexBufferObjectManager());
    final Rectangle roof =
        new Rectangle(
            cameraWidth / 2f,
            cameraHeight - 6f,
            cameraWidth - 4f,
            8f,
            this.getVertexBufferObjectManager());
    final Rectangle left =
        new Rectangle(
            6f, cameraHeight / 2f, 8f, cameraHeight - 4f, this.getVertexBufferObjectManager());
    final Rectangle right =
        new Rectangle(
            cameraWidth - 6f,
            cameraHeight / 2f,
            8f,
            cameraHeight - 4f,
            this.getVertexBufferObjectManager());
    ground.setColor(0f, 0f, 0f);
    roof.setColor(0f, 0f, 0f);
    left.setColor(0f, 0f, 0f);
    right.setColor(0f, 0f, 0f);
    groundWallBody =
        PhysicsFactory.createBoxBody(
            this.mPhysicsWorld, ground, BodyType.StaticBody, WALL_FIXTURE_DEF);
    roofWallBody =
        PhysicsFactory.createBoxBody(
            this.mPhysicsWorld, roof, BodyType.StaticBody, WALL_FIXTURE_DEF);
    leftWallBody =
        PhysicsFactory.createBoxBody(
            this.mPhysicsWorld, left, BodyType.StaticBody, WALL_FIXTURE_DEF);
    rightWallBody =
        PhysicsFactory.createBoxBody(
            this.mPhysicsWorld, right, BodyType.StaticBody, WALL_FIXTURE_DEF);
    this.mScene.attachChild(ground);
    this.mScene.attachChild(roof);
    this.mScene.attachChild(left);
    this.mScene.attachChild(right);

    Rectangle GravityRect =
        new Rectangle(300f, 240f, 100f, 100f, this.getEngine().getVertexBufferObjectManager());
    GravityRect.setColor(0f, 0.7f, 0f);
    mScene.attachChild(GravityRect);
    mScene.registerTouchArea(GravityRect);
    gravityBody =
        PhysicsFactory.createBoxBody(
            mPhysicsWorld, GravityRect, BodyType.DynamicBody, boxFixtureDef);
    gravityBody.setLinearDamping(0.4f);
    gravityBody.setAngularDamping(0.6f);
    mPhysicsWorld.registerPhysicsConnector(new PhysicsConnector(GravityRect, gravityBody));

    Rectangle AntiGravityRect =
        new Rectangle(500f, 240f, 100f, 100f, this.getEngine().getVertexBufferObjectManager()) {
          @Override
          protected void onManagedUpdate(final float pSecondsElapsed) {
            super.onManagedUpdate(pSecondsElapsed);
            antigravityBody.applyForce(
                -mPhysicsWorld.getGravity().x * antigravityBody.getMass(),
                -mPhysicsWorld.getGravity().y * antigravityBody.getMass(),
                antigravityBody.getWorldCenter().x,
                antigravityBody.getWorldCenter().y);
          }
        };
    AntiGravityRect.setColor(0f, 0f, 0.7f);
    mScene.attachChild(AntiGravityRect);
    mScene.registerTouchArea(AntiGravityRect);
    antigravityBody =
        PhysicsFactory.createBoxBody(
            mPhysicsWorld, AntiGravityRect, BodyType.DynamicBody, boxFixtureDef);
    antigravityBody.setLinearDamping(0.4f);
    antigravityBody.setAngularDamping(0.6f);
    mPhysicsWorld.registerPhysicsConnector(new PhysicsConnector(AntiGravityRect, antigravityBody));

    mScene.setOnSceneTouchListener(this);
    pOnPopulateSceneCallback.onPopulateSceneFinished();
  }