OnTriggerEnter2D / OnTriggerExit2D clarification

Unity Engine
1

Hi there.
Instead of a long verbal description I prepared a little scene and a big gif :slight_smile:

using UnityEngine;

public class Trigger : MonoBehaviour
{
    [SerializeField]
    private int _counter;

    private void OnTriggerEnter2D(Collider2D collision)
    {
        _counter += 1;
    }

    private void OnTriggerExit2D(Collider2D collision)
    {
        _counter -= 1;
    }
}

As you can see I have a polygon collider which is a trigger and I count entries and exits of another collider. Somehow it appears that eventually the number of entries exceeds the number of exits.
I wonder why Unity triggers yet another enter of the collider if it’s already within?
Summoning @MelvMay in thread :slight_smile:

3148858–239273–trigger_enter_exit.unitypackage (2.93 KB)

2

Nope?

3

I won’t let my question die in this abyss. So, bump.

4

Something tells me that @MelvMay is on vacation and that’s the reason why he’s keeping silence since the end of July.
Anyway I bump this thread just in case.

5

Could be the same problem as this bug recently reported: Unity Issue Tracker - OnCollisionExit2D isn't always triggered when using polygon/edge colliders and multiple collision points

If you want to submit your problem as a bug report, that would be super useful. Also QA will get a chance to hammer on it and try to narrow it down. If not, I’ll use your package as a test when I come to fix the above.

6

Ok, thanks. I’ll send the scene I used to capture the gif with a bug report.

7

Thanks. Might want to mention this thread in your bug report so that QA don’t just close it as a duplicate.

8

well… this “anomaly” is in unity since version 4.5 or even earlier. I know because it made me crazy and the development of one of my games to hell… With every new unity version I check if it’s fixed… Continuous instead discrete tracking might help, but this will still happen in rare occasions.

9

Note that this has been fixed and is being put in all versions back to 5.6 soon.

10

Thanks. Now I can get rid of my workaround.

11

It will land in 5.6.4p1, 2017.1.2p2 and 2017.2 (first patch).