Unable to get Box2dlights to cast shadows

Question

I'm trying to use box2dlights to add lighting to my game and I have everything working except I am unable to have shadows cast with my box2d bodies. I also have collision working using category/maskBits with my various objects and I'm trying to apply the same strategy to box2dlight filters. You can see how the light just passed through the body.

EDIT: I think I may have discovered why the lights are not colliding with my box2d bodies. When I define the body shapes using "real world" scale pixel coordinates, the lights cast shadows properly, but I lose collision since the bodies are defined at pixel scale as opposed to the box2d scale I have defined. Does anyone know why the box2dlights are using real world scale?

Here is my RayHandler Setup

RayHandler.useDiffuseLight(false);
rayHandler = new RayHandler(world);
rayHandler.setAmbientLight(.5f, .5f, .2f, 1f);
rayHandler.setBlurNum(1);
rayHandler.setShadows(true);

I have a PointLight that is positioned in the center of the screen.

PointLight pl = new PointLight(game.rayHandler, 128);
pl.setDistance(1000);
pl.setPosition(Gdx.graphics.getWidth() / 2, Gdx.graphics.getHeight() / 2);
pl.setColor(Color.WHITE);
pl.setSoftnessLength(0);
Filter filter = new Filter();
filter.categoryBits = B2DVars.CATEGORY_LIGHT; // Value listed below
filter.maskBits = B2DVars.MASK_LIGHT;         // Value listed below
pl.setContactFilter(filter);

Also, my body is defined as

body = world.createBody(squareBodyDef);
PolygonShape squareShape = new PolygonShape();
squareShape.setAsBox(b2dWidth / 2, b2dWidth / 2, new Vector2(squareBodyDef.position.x * WORLD_TO_BOX, squareBodyDef.position.y * WORLD_TO_BOX), 0f);
body.setUserData(this);

FixtureDef fdef = new FixtureDef();
fdef.shape = squareShape;
fdef.density = 10.0f;
fdef.friction =  0.1f;
fdef.restitution = 1.15f;
fdef.filter.categoryBits = CATEGORY_SQUARE_OBJECTIVE; // Value listed below
fdef.filter.maskBits = MASK_SQUARE; // Value listed below

body.createFixture(fdef).setUserData(this);
squareShape.dispose();

Finally, my box2d filtering constants

public static final short CATEGORY_BALL = 1;
public static final short CATEGORY_LINE = 2;
public static final short CATEGORY_WALL = 4;
public static final short CATEGORY_SQUARE_OBJECTIVE = 8;
public static final short CATEGORY_TRIANGLE_OBJECTIVE = 16;
public static final short CATEGORY_LIGHT = 32;

public static final short LIGHT_GROUP = 1;

public static final short MASK_BALL =
                CATEGORY_LINE |
                CATEGORY_WALL |
                CATEGORY_SQUARE_OBJECTIVE |
                CATEGORY_TRIANGLE_OBJECTIVE;

public static final short MASK_LIGHT =
                CATEGORY_LINE |
                CATEGORY_SQUARE_OBJECTIVE |
                CATEGORY_TRIANGLE_OBJECTIVE |
                CATEGORY_WALL;

public static final short MASK_SQUARE =
                CATEGORY_BALL |
                CATEGORY_LIGHT;

public static final short MASK_WALL = -1

I've been going non-stop for about 3 days trying to solve this problem to no avail. Any help is appreciated!

Answer 1

The problem was that I was using the projection matrix from my main camera with the RayHandler. My main camera by default is in world/pixel units where 100 pixels = 1 box2d meter, but its projection matrix should have been in box2d units (meters).

Based on information from this post on the libgdx reddit forum, I decided to solve the problem by creating a separate camera for my box2dlights. Here was the solution I used...

// Create a separate camera for box2dlights
OrthographicCamera b2dCam = new OrthgraphicCamera(Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
b2dCam.setToOrtho(false);
b2dCam.update();

Use the camera above with the RayHandler after the box2d world.step(..) call. This camera needs to be scaled to the box2d world.

// BOX_TO_WORLD = 100 and WORLD_TO_BOX = 0.01
rayHandler.setCombinedMatrix(b2dCam.combined.scale(BOX_TO_WORLD,BOX_TO_WORLD,BOX_TO_WORLD), b2dCam.position.x * WORLD_TO_BOX, b2dCam.position.y WORLD_TO_BOX, b2dCam.viewportWidth * b2dCam.zoom, b2dCam.viewportHeight * b2dCam.zoom);
rayHandler.updateAndRender();

Finally I needed to create my light source in box2d units...

PointLight pl = new PointLight(rayHandler, 128, Color.WHITE, 1500 * WORLD_TO_BOX, (Gdx.graphics.getWidth() / 2) * WORLD_TO_BOX, (Gdx.graphics.getHeight() / 2) * WORLD_TO_BOX);

The end result: