Question OnTriggerEnter: determining which 2 triggers overlapped?

OnTriggerEnter provides the trigger you enter, but does not provide which trigger is entered.

How to know which trigger is entered? (As cheap as possible)

 

The object the script is being run on (e.g. this.gameObject) is the trigger that entered.

 

A gameObject with a rigidbody can implement the OnTriggerEnter methods etc... however a rigidbody can have multiple triggers. I would like to know which one of those triggers got entered.

 

I don't believe you can get which trigger was entered if you have multiple trigger colliders on the same GameObject. If you split your trigger colliders onto different child GameObjects and have each of them handle their own OnTriggerEnter calls you will be able to see the specific triggers being entered.

 

There can only be 1 rigidbody per parent hierarchy.
In my tests, I saw that OnTriggerEnter doesn't get called on the children of that rigidbody. Am I incorrect?

 

You don't need a rigidbody on the gameobject with the trigger colliders if there is a rigidbody on the other gameobject.