How to detect a hit inside the polygon shape, not the square texture in LibGDX+Box2d - libgdx

Question

I have an entity Actor defined by next code:
this.world = world;
this.texture = texture;
// Create the body.
BodyDef def = new BodyDef(); // (1) Give it some definition.
def.position.set(x, y + 0.5f); // (2) Position the body on the world
def.type = BodyDef.BodyType.DynamicBody;
body = world.createBody(def); // (3) Create the body.
// Now give it a shape.
PolygonShape box = new PolygonShape(); // (1) We will make a polygon.
Vector2[] vertices = new Vector2[6];
vertices[0] = new Vector2(0.04f , 0.24f );
vertices[1] = new Vector2(0.64f , 1.18f );
vertices[2] = new Vector2(1.66f , 1.8f);
vertices[3] = new Vector2(1.92f , 1.52f);
vertices[4] = new Vector2(1.18f , 0.66f);
vertices[5] = new Vector2(0.26f , 0.03f);
box.set(vertices); // (4) And put them in the shape.
fixture = body.createFixture(box, 3); // (5) Create the fixture.
fixture.setUserData("actor"); // (6) And set the user data to enemy.
box.dispose(); // (7) Destroy the shape when you don't need it.
// Position the actor in the screen by converting the meters to pixels.
setPosition((x - 0.5f) * PIXELS_IN_METER, y * PIXELS_IN_METER);
setSize(PIXELS_IN_METER, PIXELS_IN_METER);
this.setDebug(true);
When I add last line setDebug my Actor abject is surrounded by a squared shape and my hits affect to this square and not the REAL shape defined by my poligon. This hit detection is catch by touchDown (InputProcessor) event:
public boolean touchDown(int screenX, int screenY, int pointer, int button) {
Vector2 coord = stage.screenToStageCoordinates(new Vector2((float)screenX,(float)screenY));
Actor hitActor = stage.hit(coord.x,coord.y,false);
if(hitActor != null) {
Gdx.app.log("myapp", "hit!!!!!");
}
return true;
}
What am I doing wrong? I just only want to detect hit on my game actor items.
Thank you in advance!!

Answer 1

Scene2D actor and Box2D body are not the same - if you want to see your body being debug you have to use Box2D's DebugRenderer
//creating debug renderer in show method or as class'es field
Box2DDebugRenderer debugRenderer = new Box2DDebugRenderer();
//render() method
debugRenderer.render(world, camera.combined);
Then you'll see that your body's shape and actor's shape are not the same. What's more they probably won't have same position since you are not updateing your actor's position due to body (you should do this in actor's act overriden method by using something like setPosition(body.getPosition().x, body.getPosition().y); - remember that origin for actor is on its left bottom corner when the body has it's origin at the center!).
Unfortunately actor can be rectangular only so it is not possible to create same shape as for body. However you can use you actor as bounding box and set it's size to overlap whole body (it will be changing if body will rotate!).
Another solution is not to catch listener on body but to implement some mechanism like creating a body after click and check collision