Raycasting 2D Java Script --- Always finds something even though I have no other colliders

Unity Engine
1

I’m trying to make a script that shoots a raycast then runs a command if it detects a collider. However, I have no other colliders on screen other than the backgrounds, but those are set to ignore the raycast. What is going wrong? Here is my code: (it is in the update function)

var raycastDist = 1;
var hit: RaycastHit2D = Physics2D.Raycast(transform.position, -Vector2.right, raycastDist);

// If it hits something…
if (hit.collider != null) {
print(“Yes!”);

}
else { print(“Nope”);}

What is going wrong?

2

Maybe it’s detecting the collider that overlaps transform.position. You can turn on/off the ability to detect colliders that overlap the start-point of ray/line casts in the 2D physics settings with the property ‘RaycastStartsInCollider’

This feature was added in 4.5.5 patch 2.

3

just for a bit of extra info, you could also just under print(“Yes!”);, put in

Debug.Log ("Hit collider : " + hit.collider.tag);

or

Debug.Log ("Hit collider : " + hit.collider.name);

give you an idea what its hitting. if its got a tag, or just use the collider name depending on how your scene is set up.

4

Thank you! Turns out it was hitting its own collider. Just need to start the raycast in front of it. I appreciate it!

5

Just to ensure you got the correct info; if you’re hitting your own collider and the ray is starting inside that collider then turn-off the ‘RaycastStartsInCollider’ or for a less global solution, simply set the GO that contains this collider to a different layer than the things you’re trying to detect and specify the layers you want in the cast, assuming this is okay to do in your game.