PhysicsCollider ray casting

Unity Engine
, ,
1

I have a particular collider I’ve been trying to raycast against. I’m getting zero results so far, nothing happens no matter what I do. My goal is to know if my mouse pointer is inside the collider. Trying to cast a ray from the mouse position to the center of the collider. Why doesn’t this work?

intersectPlane.Raycast(screenPointToRay, out var mouseHit);

mouseWorldPos = screenPointToRay.GetPoint(mouseHit);

Entities.WithoutBurst().ForEach(
((in PhysicsCollider collider, in BoxGrid grid, in Rotation rotation, in Translation translation)) =>
{
if (!collider.Value.Value.CastRay(ray, out var hit))
{
    
    
   
    //snap mouse to grid
    Draw.WireBox(p,rotation.Value ,1);       
}
}).Run();

CastRay always returns false. Entity has a PhysicsCollider and a PhysicsBody. I don’t think it needs a physics body to be able to detect ray collisions, but I did try it with and with out one. The objects are also in a Sub Scene. Thanks in advance.

2

You’ll need to transform the ray into collider space. The collider doesn’t know about the entity’s rotation and translation.

I guess this will also be very slow if you have more than a few entities, so it would probably be better to use PhysicsWorld.CastRay(), which is accelerated by the broadphase. That way you don’t need to iterate over entities or transform rays either.

3

Thanks I’ll try to figure out how to transform the ray. I’m doing it this way in this case because I just want to know about a handful of entities (prolly like <10 tops). Tho I don’t know if my case could still be faster if I use the PhysicsWorld to cast the ray, I imagine that would test all colliders by default.