private static void setUpObjects() {
BodyDef boxDef = new BodyDef();
boxDef.position.set(320 / 30 / 2, 240 / 30 / 2);
boxDef.type = BodyType.DYNAMIC;
PolygonShape boxShape = new PolygonShape();
boxShape.setAsBox(0.75f, 0.75f);
Body box = world.createBody(boxDef);
FixtureDef boxFixture = new FixtureDef();
boxFixture.density = 0.1f;
boxFixture.shape = boxShape;
box.createFixture(boxFixture);
bodies.add(box);
BodyDef groundDef = new BodyDef();
groundDef.position.set(0, 0);
groundDef.type = BodyType.STATIC;
PolygonShape groundShape = new PolygonShape();
groundShape.setAsBox(1000, 0);
Body ground = world.createBody(groundDef);
FixtureDef groundFixture = new FixtureDef();
groundFixture.density = 1;
groundFixture.restitution = 0.3f;
groundFixture.shape = groundShape;