terrain not properly rendering

Question

I'm extending the terrain quad with resources from various tutorials and have the following code:

public class WorldTerrain extends TerrainQuad {

    public static final String NAME = "terrain";
    public static final int PATCH_SIZE = 9;
    public static final int TOTAL_SIZE = 33;
    private static Vector3f spawnLocation = new Vector3f(13, 3, 16);
    private Material mat_terrain;

    private void loadText(AssetManager assetManager) {
        /**
         * 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(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/GrassRocky.png");
        dirt.setWrap(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(WrapMode.Repeat);
        mat_terrain.setTexture("Tex3", rock);
        mat_terrain.setFloat("Tex3Scale", 128f);
    }

    private static float[] generateHeightMap(AssetManager assetManager) {
        AbstractHeightMap heightmap = null;
        try {
            heightmap = new HillHeightMap(1024, 100, 2, 10, 1);
        } catch (Exception ex) {
            Logger.getLogger(Interface.class.getName()).log(Level.SEVERE, null, ex);
        }
        return heightmap.getHeightMap();
    }

    public static Vector3f getSpawnLocation() {
        return spawnLocation;
    }

    public WorldTerrain(Interface app) {
        super(NAME, PATCH_SIZE, TOTAL_SIZE, generateHeightMap(app.getAssetManager()));
        loadText(app.getAssetManager());
        setMaterial(mat_terrain);

        setModelBound(new BoundingBox());
        setLocalTranslation(32f, 0f, 32f);

        List<Camera> cameras = new ArrayList<Camera>();
        cameras.add(app.getCamera());

        RigidBodyControl landscape = new RigidBodyControl(0.0f);
        addControl(landscape);

and the interface:

public class Interface extends SimpleApplication {

  private TerrainQuad terrain;
  Material mat_terrain;

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

  @Override
  public void simpleInitApp() {
    flyCam.setMoveSpeed(50);

    terrain = new WorldTerrain(this);
    rootNode.attachChild(terrain);
  }

This gives the following result: as you can see large parts of the terrain are not rendering (ignore the weird mountains those are only tests). If I move the camera around these holes move around suggesting it's a rendering problem in the terrain. Anybody who knows how to fix?

Answer 1

Trying changing

setModelBound(new BoundingBox());

to

BoundingSphere bs = new BoundingSphere();
bs.setCenter(new Vector3f(32,0,32));
bs.setRadius(1000000);
setModelBound(bs);

Edit Larethian (short Version) (confirmed working on example code):

setModelBound( new BoundingSphere(1000000, new Vector3f(32f, 0f, 32f)) );

As pointed out in the comments below a bounding volume with this large of a radius shouldn't really be used...although the fact that it is working gives you an idea of what the original problem was. If you wish to use bounding spheres realistically what you can do is try setting the radius to be "PATCH_SIZE".

Answer 2

Maybe they are being culled for being partly outside the view area? Might be worth looking at the code selecting what you render instead of the terrain code.

(Or setting near and far plane differently and/or moving the camera further away since it seems the engine is not a custom solution)