LibGDX Box2D not rendering

Question

I am new to Box2D and LibGDX and I am trying to render a simple test. The code should render a 2x2 box, but it doesn't Here is my code:

public class PhysicsDemo implements ApplicationListener {
World world = new World(new Vector2(0, -20), true);
Box2DDebugRenderer debugRenderer;
private OrthographicCamera camera;


@Override
public void create() {      

    camera = new OrthographicCamera();
    camera.position.set(0, 0, 0);


    //Ground body
    BodyDef groundBodyDef =new BodyDef();
    groundBodyDef.position.set(0.0f, -20f);
    Body groundBody = world.createBody(groundBodyDef);
    PolygonShape groundBox = new PolygonShape();
    groundBox.setAsBox(50.0f, 10.0f);
    groundBody.createFixture(groundBox, 0.0f);

    //Dynamic Body
    BodyDef bodyDef = new BodyDef();
    bodyDef.type = BodyType.DynamicBody;
    bodyDef.position.set(0.0f, 4.0f);
    Body body = world.createBody(bodyDef);
    PolygonShape dynamicBox = new PolygonShape();
    dynamicBox.setAsBox(1.0f, 1.0f);
    FixtureDef fixtureDef = new FixtureDef();
    fixtureDef.shape = dynamicBox;
    fixtureDef.density = 1.0f;
    fixtureDef.friction = 0.3f;
    body.createFixture(fixtureDef);

    debugRenderer = new Box2DDebugRenderer();


}





@Override
public void dispose() {



}

@Override
public void render() {      

    Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
    debugRenderer.render(world, camera.combined);


}

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

@Override
public void pause() {
}

@Override
public void resume() {
}
}

I can't seem to display anything, all I get is a black screen. Does anyone know what's wrong?

Thanks!

Answer 1

I had the same problem. You mentioned the solution in the comments section but i wanted to give an official answer to this.

in your code (and mine) there was no camera.viewportWidth and camera.viewportHeight set... just set these two values either explicitly via camera.viewportWidth = Gdx.graphics.getWidth() or by passing the values in through the constructor like so:

OrthographicCamera camera = new OrthographicCamera(Gdx.graphics.getWidth(), 
                                                   Gdx.graphics.getHeight());

(for those who don't know i am using the Gdx method of getting the screen resolution because box2d is usually used in Java with libGDX, you may substitute Gdx.graphics.getWidth() with whatever screen resolution you are using)

Answer 2

Set your camera position like this

camera.position.set(camera.viewportWidth * .5f, camera.viewportHeight * .5f, 0f);

and add this

camera.update();

Answer 3

i'have the same problem i've solved it to call for all super()

super.pause();

super.resize(width, height);

super.render();

super.dispose();

super.resume();