BlockTerrainControl blockTerrain;
    private BulletAppState bulletAppState;

    public static final Block BlockGrass = new Block(new BlockSkin(new BlockSkin_TextureLocation(0, 0), false));
    public static final Block BlockDirt = new Block(new BlockSkin(new BlockSkin_TextureLocation(1, 0), false));
    public static final Block BlockBedrock = new Block(new BlockSkin(new BlockSkin_TextureLocation(2, 0), false));
    public static final Block BlockSand = new Block(new BlockSkin(new BlockSkin_TextureLocation(3, 0), false));

    @Override
    public void simpleInitApp() {
        bulletAppState = new BulletAppState();
        stateManager.attach(bulletAppState);

        CubesSettings settings = new CubesSettings(this);
        settings.setDefaultBlockMaterial("Textures/cubes/terrainBig.png");
        settings.setChunkSizeX(32);
        settings.setChunkSizeY(128);
        settings.setChunkSizeZ(32);

        Material material = new Material(assetManager, "Common/MatDefs/Light/Lighting.j3md");
        material.setTexture("DiffuseMap", assetManager.loadTexture("Textures/cubes/terrainBig.png"));
        material.setTexture("NormalMap", assetManager.loadTexture("Textures/cubes/n_terrainBig.png"));
        material.setBoolean("UseMaterialColors",false);
        material.setColor("Diffuse",ColorRGBA.White);
        material.setColor("Specular",ColorRGBA.White);
        material.setFloat("Shininess", 64f);
        settings.setBlockMaterial(material);

        BlockManager.register(BlockGrass);
        BlockManager.register(BlockDirt);
        BlockManager.register(BlockBedrock);
        BlockManager.register(BlockSand);

        blockTerrain = new BlockTerrainControl(settings, new Vector3Int(1, 1, 1));

        blockTerrain.setBlockArea(new Vector3Int(0, 0, 0), new Vector3Int(32, 1, 32), BlockBedrock);
        blockTerrain.setBlockArea(new Vector3Int(0, 1, 0), new Vector3Int(32, 3, 32), BlockDirt);
        blockTerrain.setBlockArea(new Vector3Int(0, 3, 0), new Vector3Int(32, 1, 32), BlockGrass);
        //blockTerrain.setBlock(new Vector3Int(0, 0, 0), BlockGrass);
        //blockTerrain.setBlock(new Vector3Int(1, 0, 0), BlockDirt);

        Node terrainNode = new Node();
        terrainNode.addControl(blockTerrain);
        rootNode.attachChild(terrainNode);

        cam.setLocation(new Vector3f(-10, 100, 16));
        cam.lookAtDirection(new Vector3f(0, 0, 0), Vector3f.UNIT_Y);
        flyCam.setMoveSpeed(50);

        terrainNode.setShadowMode(ShadowMode.CastAndReceive);

        terrainNode.addControl(new RigidBodyControl(0));
        bulletAppState.getPhysicsSpace().addAll(terrainNode);

            /** A white ambient light source. */
        AmbientLight ambient = new AmbientLight();
        ambient.setColor(ColorRGBA.White);
        rootNode.addLight(ambient);
            /** Show scattered light beams when camera looks into "sun". */
        /*FilterPostProcessor fpp=new FilterPostProcessor(assetManager);
        LightScatteringFilter sunlight = new LightScatteringFilter(new Vector3f(.5f,.5f,.5f).multLocal(-3000));
        fpp.addFilter(sunlight);
        viewPort.addProcessor(fpp); */
            /** A white, directional light source */
        DirectionalLight sun = new DirectionalLight();
        sun.setDirection((new Vector3f(-0.5f, -0.5f, -0.5f)).normalizeLocal());
        sun.setColor(ColorRGBA.White);
        rootNode.addLight(sun);
            /* this shadow needs a directional light */
        DirectionalLightShadowRenderer dlsr = new DirectionalLightShadowRenderer(assetManager, 1024, 2);
        dlsr.setLight(sun);
        viewPort.addProcessor(dlsr);
    }