Bug OnTriggerExit2D doesn't work by changing localScale to a tiny number.

OnTriggerExit2D doesn't work with all types of collider which has tiny localScale except for circle collider.

There are a box trigger and a circle collider in the scene.


And box trigger has a script to log the trigger callbacks like this:

Code (CSharp):

1.  
2.     private void OnTriggerEnter2D(Collider2D collision) {
3.         Debug.Log($"{this.gameObject.name}'s OnTriggerEnter2D: {collision.gameObject.name}");
4.     }
5.  
6.     private void OnTriggerExit2D(Collider2D collision) {
7.         Debug.Log($"{this.gameObject.name}'s OnTriggerExit2D: {collision.gameObject.name}");
8.     }
9.  

And a script to reproduce this bug:

Code (CSharp):

1.  
2. public class SetLocalScale : MonoBehaviour {
3.     public Transform target;
4.     public float targetScale = 0.001f;
5.  
6.     IEnumerator Start() {
7.         // Wait OnTriggerEnter2D.
8.         yield return null;
9.  
10.         Debug.Log($"Set {target.gameObject.name}'s localScale to {targetScale}");
11.         target.localScale = new Vector3(targetScale, targetScale, 1f);
12.     }
13. }
14.  

So the idea is the box trigger should scale to the targetScale at the second frame and two shapes won't overlap, then the OnTriggerExit2D() will be invoked.

It works fine with targetScale=0.1f.
but it doesn't work with targetScale=0.001f.

video: https://i.imgur.com/creUxOk.mp4

Case 1329061

 

No, I didn't get any warning about this.

You've stored the state before recreated. Does it hard to detect if the shape is degenerate and send a Exit if it has entered before?

Thanks for explanation.
It's not a big issue tho. Just feeling it should be handled.
Or be an option like "Callbacks On Disable" do in ProjectSettings.

 

Oh I see. I thought you are talking about console.

As you said, if shape count is a way to check the degenerate shape. It should not that hard to check them when you recreate the shape, right? I just want the Enter and Exit callbacks are always pair.