Is OnMouse.. fundamentally broken on 2D overlapping object colliders?

All my sprites are rendering perfectly in correct order using the layer/sorting system on the same z-axis - in accordance with Unity's own recommended approach to 2D rendering - and OnMouseEnter works perfectly on each of them individually when they're separated.

But when they are close together & overlap, OnMouseEnter/Over is not able to determine the correct collider to use. So I often get rear objects running the OnMouseEnter code incorrectly.

Is there an obvious solution to this that I'm missing? It seems strange that there is no built in function for a 2D-OnMouse event to look at multiple colliders on the same Z-axis & then simply check the Y position to determine which is the correct gameobject.

Surely detecting overlapping fore/rear sprites with the pointer correctly is a fundamental necessity in 2D game development? Is there no built-in way to do this?

 

Am I going to have to end up basically firing a RayCastAll from the pointer position every frame in the update - which logs multiple colliders and registers the one with the lowest Y position?

And then, if that object is set to do something if the mouse is confirmed as over the collider it executes the code?

Esentially, remaking the whole MouseEnter/Over/Exit process from scratch and having it permanently switched on for multiple collider sorting.

If anyone's got a better idea, I'm all ears!

 

Well, I implemented the once-a-frame RayCastAll+Iteration method to sort the colliders and it does the job. Although I'm a bit concerned about the extra overhead, but since I'm not coming across any other solutions I guess that'll have to suffice.

I'm wondering whether the whole 2D sprite renderer/collider concept itself needs to be reworked from the ground up by the Unity team, so it can reconcile itself with the pointer position in a much more natural way. The engine always knows where the pointer position is, and the engine always knows whether a sprite should be at the front or not: Putting those two bits of information together for an instant decision on whether the pointer is over the front sprite sounds reasonable surely?

Is it worth me putting in a feature request for this? Or even raising this as a bug? Since OnMouse is effectively unusable for 2D game development with overlapping sprites. Seems to be a broken feature as far as I can work out.

 

I have found OnPointerEnter to be a working alternative, for anyone else having trouble with OnMouseEnter

 

I was told by another moderator to post it in the Physics folder, which I did here:

https://forum.unity.com/threads/bug...axis-trigger-incorrectly.647725/#post-4339663

But it never got a response from anyone on the Unity team. Not even an acknowledgement.

 

Wherever the correct location should be for that Feedback/Bugfix request I linked to above (which I also formally submitted), it's not great that I've never had a response to it.

 

it's prob too late for this topic, but I never found a solution either.
But what I did to make it work is enable/disable the colliders. Everytime I evaluate an OnMouseEnter for example, I will disable any colliders that could be overlapping with it, leaving it the only collider under the mouse, and on OnMouseExit, I will re-enable all colliders. So if there's overlapping situations, this will make sure that one gets picked and gets sticked to it until it is no longer casted by the cursor.