JMonkey Endless Terrain Example: How to change the render distance

Question

The Jmoneky Engine gives example code for endless randomly generated Terrain. My Problem is, the code has no comments or indicators to edit the View distance. I am trying to use this example code to build a game, but it looks really bad if the render distance is so short you can see the bottom of the world(void)

The Code:

public class TerrainFractalGridTest extends SimpleApplication {   
private Material mat_terrain;
private TerrainGrid terrain;
private float grassScale = 64;
private float dirtScale = 16;
private float rockScale = 128;

public static void main(final String[] args) {
    TerrainFractalGridTest app = new TerrainFractalGridTest();
    app.start();
}
private CharacterControl player3;
private FractalSum base;
private PerturbFilter perturb;
private OptimizedErode therm;
private SmoothFilter smooth;
private IterativeFilter iterate;

@Override
public void simpleInitApp() {
    this.flyCam.setMoveSpeed(100f);
    ScreenshotAppState state = new ScreenshotAppState();
    this.stateManager.attach(state);

    // TERRAIN TEXTURE material
    this.mat_terrain = new Material(this.assetManager, "Common/MatDefs/Terrain/HeightBasedTerrain.j3md");

    // Parameters to material:
    // regionXColorMap: X = 1..4 the texture that should be appliad to state X
    // regionX: a Vector3f containing the following information:
    //      regionX.x: the start height of the region
    //      regionX.y: the end height of the region
    //      regionX.z: the texture scale for the region
    //  it might not be the most elegant way for storing these 3 values, but it packs the data nicely :)
    // slopeColorMap: the texture to be used for cliffs, and steep mountain sites
    // slopeTileFactor: the texture scale for slopes
    // terrainSize: the total size of the terrain (used for scaling the texture)
    // GRASS texture
    Texture grass = this.assetManager.loadTexture("Textures/Terrain/splat/grass.jpg");
    grass.setWrap(WrapMode.Repeat);
    this.mat_terrain.setTexture("region1ColorMap", grass);
    this.mat_terrain.setVector3("region1", new Vector3f(15, 200, this.grassScale));

    // DIRT texture
    Texture dirt = this.assetManager.loadTexture("Textures/Terrain/splat/dirt.jpg");
    dirt.setWrap(WrapMode.Repeat);
    this.mat_terrain.setTexture("region2ColorMap", dirt);
    this.mat_terrain.setVector3("region2", new Vector3f(0, 20, this.dirtScale));

    // ROCK texture
    Texture rock = this.assetManager.loadTexture("Textures/Terrain/Rock2/rock.jpg");
    rock.setWrap(WrapMode.Repeat);
    this.mat_terrain.setTexture("region3ColorMap", rock);
    this.mat_terrain.setVector3("region3", new Vector3f(198, 260, this.rockScale));

    this.mat_terrain.setTexture("region4ColorMap", rock);
    this.mat_terrain.setVector3("region4", new Vector3f(198, 260, this.rockScale));

    this.mat_terrain.setTexture("slopeColorMap", rock);
    this.mat_terrain.setFloat("slopeTileFactor", 32);

    this.mat_terrain.setFloat("terrainSize", 513);

    this.base = new FractalSum();
    this.base.setRoughness(0.7f);
    this.base.setFrequency(1.0f);
    this.base.setAmplitude(1.0f);
    this.base.setLacunarity(2.12f);
    this.base.setOctaves(8);
    this.base.setScale(0.02125f);
    this.base.addModulator(new NoiseModulator() {

        @Override
        public float value(float... in) {
            return ShaderUtils.clamp(in[0] * 0.5f + 0.5f, 0, 1);
        }
    });

    FilteredBasis ground = new FilteredBasis(this.base);

    this.perturb = new PerturbFilter();
    this.perturb.setMagnitude(0.119f);

    this.therm = new OptimizedErode();
    this.therm.setRadius(5);
    this.therm.setTalus(0.011f);

    this.smooth = new SmoothFilter();
    this.smooth.setRadius(1);
    this.smooth.setEffect(0.7f);

    this.iterate = new IterativeFilter();
    this.iterate.addPreFilter(this.perturb);
    this.iterate.addPostFilter(this.smooth);
    this.iterate.setFilter(this.therm);
    this.iterate.setIterations(1);

    ground.addPreFilter(this.iterate);

    this.terrain = new TerrainGrid("terrain", 33, 129, new FractalTileLoader(ground, 256f));

    this.terrain.setMaterial(this.mat_terrain);
    this.terrain.setLocalTranslation(0, 0, 0);
    this.terrain.setLocalScale(2f, 1f, 2f);
    this.rootNode.attachChild(this.terrain);

    TerrainLodControl control = new TerrainGridLodControl(this.terrain, this.getCamera());
    control.setLodCalculator(new DistanceLodCalculator(33, 2.7f)); // patch size, and a multiplier
    this.terrain.addControl(control);



    this.getCamera().setLocation(new Vector3f(0, 300, 0));

    this.viewPort.setBackgroundColor(new ColorRGBA(0.7f, 0.8f, 1f, 1f));


}

@Override
public void simpleUpdate(final float tpf) {
}}

So following what J Atkin said about Terrain Grid, I found a endless terrain example that is a terrain grid. The Cells loaded class is protected, which means I have to extends it in the class to access it. In Jmonkey, the main class has to extend a simple application in order to run. Java doesn't allow multiple extensions, therefor I build a second class to allow access.

public class ViewTerrain extends TerrainGrid{
public void setView(int numberofcells){
    super.cellsLoaded = numberofcells;
}
}

problem I am having with this class is that I don't know how to keep the original declaration IE.

 this.terrain = new TerrainGrid("terrain", 65, 257, new ImageTileLoader(assetManager, new Namer() {

        public String getName(int x, int y) {
            return "Scenes/TerrainMountains/terrain_" + x + "_" + y + ".png";
        }

    }));

Answer 1

Looking at the source it seems TerrainGrid dynamically redefines an internal TerrainQuad tree based upon which grid the camera is in and the surrounding grid tiles. It would seem to me that you should define these tiles to be the size of the area you would like visible at any one time. Try updating patchSize in the constructor to be larger.