LibGDX 3d not working?

Miscellaneous Topics
#1

I am trying to follow this tutorial on LibGDX:

but whenever I put the code into the program, i get a whole bunch of errors
here is my code:


package com.me.main;

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.VertexAttributes.Usage;

public class Game implements ApplicationListener {
	public PerspectiveCamera cam;
    public ModelBatch modelBatch;
    public Model model;
    public ModelInstance instance;
	@Override
	public void create() {		
		cam = new PerspectiveCamera(67, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
        cam.position.set(10f, 10f, 10f);
        cam.lookAt(0,0,0);
        cam.near = 1f;
        cam.far = 300f;
        cam.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 dispose() {
		 model.dispose();modelBatch.dispose();
	        model.dispose();

	@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(cam);
	        modelBatch.render(instance);
	        modelBatch.end();
	}

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

	@Override
	public void pause() {
	}

	@Override
	public void resume() {
	}
}

and the error:


Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
	ModelBatch cannot be resolved to a type
	Model cannot be resolved to a type
	ModelInstance cannot be resolved to a type
	ModelBuilder cannot be resolved to a type
	ModelBuilder cannot be resolved to a type
	Model cannot be resolved to a type
	Material cannot be resolved to a type
	ColorAttribute cannot be resolved
	ModelInstance cannot be resolved to a type
	ModelInstance cannot be resolved to a type
	Model cannot be resolved to a type
	Model cannot be resolved to a type
	ModelBatch cannot be resolved to a type
	Model cannot be resolved to a type
	Syntax error, insert "}" to complete MethodBody
	ModelBatch cannot be resolved to a type
	ModelBatch cannot be resolved to a type
	ModelInstance cannot be resolved to a type
	ModelBatch cannot be resolved to a type

	at com.me.main.Game.<init>(Game.java:12)
	at com.me.main.Main.main(Main.java:14)