box2d主体根据世界宽度/高度单位移动

I've got the following settings:

我有以下设置:

private static final float SCENE_WIDTH = 1280; 
private static final float SCENE_HEIGHT =720;

//Gravity
world = new World(new Vector2(0,-9.8f), true);

camera = new OrthographicCamera();
viewport = new FitViewport(SCENE_WIDTH, SCENE_HEIGHT, camera);
//viewport.apply();
camera.position.set(SCENE_WIDTH * 0.5f, SCENE_HEIGHT * 0.5f, 0);
pr