Shadow does not apply in J3o

Hi!
I create a terrain with the editor and I try to import in the game, but when I add the PssmShadowRenderer, it only darkens.

Code:

[java]public class HelloScene extends SimpleApplication
{
Material mat_terrain;
Node sceneNode;
DirectionalLight sun1;

public static void main(String[] args)
{
    HelloScene app = new HelloScene();
    app.start();
}

public void simpleInitApp()
{       
    initCamera();
    initMaterial();
    initLight();
    initShadow();
    String workHome = System.getProperty("user.dir");
    assetManager.registerLocator(workHome, FileLocator.class);
    sceneNode = (Node)assetManager.loadModel("assets/Scenes/testScene.j3o");
    sceneNode.setName("testSceneNode");
    sceneNode.setLocalTranslation(0, -200, 0);              
    sceneNode.setMaterial(mat_terrain);
    sceneNode.setShadowMode(RenderQueue.ShadowMode.CastAndReceive);
    rootNode.attachChild(sceneNode);  
    
    
}
private void initCamera()
{
    flyCam.setMoveSpeed(50);
}
private void initMaterial()
{
    /** 1. Create terrain material and load four textures into it. */
  mat_terrain = new Material(assetManager, 
          "Common/MatDefs/Terrain/Terrain.j3md");

  /** 1.1) Add ALPHA map (for red-blue-green coded splat textures) */
  mat_terrain.setTexture("Alpha", assetManager.loadTexture(
          "Textures/Terrain/splat/alphamap.png"));

  /** 1.2) Add GRASS texture into the red layer (Tex1). */
  Texture grass = assetManager.loadTexture(
          "Textures/Terrain/splat/grass.jpg");
  grass.setWrap(Texture.WrapMode.Repeat);
  mat_terrain.setTexture("Tex1", grass);
  mat_terrain.setFloat("Tex1Scale", 64f);

  /** 1.3) Add DIRT texture into the green layer (Tex2) */
  Texture dirt = assetManager.loadTexture(
          "Textures/Terrain/splat/dirt.jpg");
  dirt.setWrap(Texture.WrapMode.Repeat);
  mat_terrain.setTexture("Tex2", dirt);
  mat_terrain.setFloat("Tex2Scale", 32f);

  /** 1.4) Add ROAD texture into the blue layer (Tex3) */
  Texture rock = assetManager.loadTexture(
          "Textures/Terrain/splat/road.jpg");
  rock.setWrap(Texture.WrapMode.Repeat);
  mat_terrain.setTexture("Tex3", rock);
  mat_terrain.setFloat("Tex3Scale", 128f);
}
private void initLight()
{
    sun1 = new DirectionalLight();
    sun1.setColor(ColorRGBA.White.clone().multLocal(1.7f));
    sun1.setDirection(new Vector3f(0f, 0f, 0f));
    rootNode.addLight(sun1);
}

private void initShadow()
{
    PssmShadowRenderer pssm = new PssmShadowRenderer(assetManager, 1024, 4);
    pssm.setDirection(sun1.getDirection());
    pssm.setFilterMode(PssmShadowRenderer.FilterMode.PCF4);
    viewPort.addProcessor(pssm);
    
    rootNode.setShadowMode(RenderQueue.ShadowMode.Receive);
    
}

} [/java]