World3D class | stackexchange

package com.lockedprogramming.pacificblitz.world;

import com.badlogic.gdx.ApplicationListener;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.PerspectiveCamera;
import com.badlogic.gdx.graphics.Pixmap;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.GLTexture;
import com.badlogic.gdx.graphics.VertexAttributes.Usage;
import com.badlogic.gdx.graphics.g3d.Material;
import com.badlogic.gdx.graphics.g3d.Model;
import com.badlogic.gdx.graphics.g3d.ModelBatch;
import com.badlogic.gdx.graphics.g3d.ModelInstance;
import com.badlogic.gdx.graphics.g3d.attributes.ColorAttribute;
import com.badlogic.gdx.graphics.g3d.attributes.FloatAttribute;
import com.badlogic.gdx.graphics.g3d.attributes.TextureAttribute;
import com.badlogic.gdx.graphics.g3d.utils.ModelBuilder;


public class World3D implements ApplicationListener {
    public PerspectiveCamera playercam;
    public ModelBatch modelBatch;
    public Model model;
    public ModelInstance instance;
        Texture ground = new Texture(Gdx.files.internal("img/tileablegrid.png"));
    @Override
    public void create() {
        modelBatch = new ModelBatch();
        playercam = new PerspectiveCamera(67, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
        playercam.position.set(10f, 10f, 10f);
        playercam.lookAt(0,0,0);
        playercam.near = 1f;
        playercam.far = 300f;
        playercam.update();
        ModelBuilder modelBuilder = new ModelBuilder();
        model = modelBuilder.createBox(5f, 5f, 5f,
            new Material(ColorAttribute.createDiffuse(Color.GREEN)),
            Usage.Position | Usage.Normal);
        instance = new ModelInstance(model);
    }

    @Override
    public void resize(int width, int height) {
    }

    @Override
    public void render() {
         Gdx.gl.glViewport(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
            Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT);

            modelBatch.begin(playercam);
            modelBatch.render(instance);
            modelBatch.end();
    }

    @Override
    public void pause() {
    }

    @Override
    public void resume() {
    }

    @Override
    public void dispose() {
        modelBatch.dispose();
        ground.dispose();
        model.dispose();
    }

}