Particle collision detection with collider2d that has "is Trigger" checked. How?

Unity Engine
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1

Dear all,

This surely has been asked before but can’t seem to find it. If I have a particle system and a gameobject with a rigidbody 2d kinematic on it and a polygon collider 2D with “is Trigger” checked the following code does not react:

private void OnParticleCollision(GameObject other)
{
if (other.CompareTag(“myParticleSystem”))
{
Destroy(gameObject);
}
}

If I uncheck the “is Trigger” Box everything works as collision is detected and I suspect it is because particle system act as 2d physics and when the go through the collider (“is Trigger”) there is no reaction7feedback.

My question is : Can a gameobject with a rigidbody 2d kinematic and a polygon collider2d detect a particle collision with a function in a script (like the one above) and if yes what is the correct function (if not OnParticleCollision)?

Many thanks in advance for your feedback.

2

Being Kinematic (how it moves) and a specific collider isn’t relevant to the question and note that the 2D physics system doesn’t know anything about particles. The particle system performs Circle queries just like you would, it’s a user of the physics system as you are.

It either performs CircleCast queries when you want collisions or it performs OverlapCircle queries when you want overlaps (triggers). AFAIK it has a CollisionModule for collisions and a TriggerModule for triggers.

This is well documented in the Particle System manual. Did you read the docs or look at any online tutorials (there are lots)?

https://docs.unity3d.com/Manual/PartSysCollisionModule.html
https://docs.unity3d.com/Manual/PartSysTriggersModule.html

3

Thank you for your reply and insight. I understood some fundamentals about the Particle system which indeed I didn’t research before asking my question.

What I wanted was a script / function how to detect collision event though the Particle System goes through the collider which “Is Trigger”.

The solution I found is, as gratefully suggested by MelvMay, is in the well documented Particle System Manual:

  • You need to start from the particle system (PS) instead from the gameObject

  • on the PS you need to uncheck Collsion module and active Triggers module

  • you want use the action option “Callback” for the trigger condition (like Enter, Exit, etc.)

  • the script is on the PS and the function needed is void OnParticleTrigger() where you can specify what happens to the particles

  • this is all perfectly explained with ready to use script in the Unity - Manual: Triggers module