How can I destroy particles on collision with specific a GameObject?

Question

I wrote a script to manage my Particle System emission. The starting lifespan is set to infinite so that the particle never dies until it reaches a specific collider. I didn't find any method to destroy a specific particle in the Unity Manual.

How can I do this?

Here's the code (updated to show the partial fix)

using UnityEngine;
using System.Collections.Generic;

public class PlayerDamage : MonoBehaviour
{
    private ParticleSystem ps;
    public List<ParticleCollisionEvent> collisionEvents;
    public int attackValue = 1;

    //
    [Range(0.0f, 100f)]
    public int maxParticles;
    public float particleLife;
    public bool neverDies;
    public float particleSpeed = 8.0F;


    void Start()
    {
        ps = GetComponent<ParticleSystem>();
        collisionEvents = new List<ParticleCollisionEvent>();
        //
        var collision = ps.collision;
        collision.enabled = true;
        collision.type = ParticleSystemCollisionType.World;
        collision.mode = ParticleSystemCollisionMode.Collision3D;
    }

    void OnParticleCollision(GameObject other)
    {
        int numCollisionEvents = ps.GetCollisionEvents(other, collisionEvents);

        Rigidbody rb = other.GetComponent<Rigidbody>();
        int i = 0;

        while (i < numCollisionEvents)
        {
            if (rb.CompareTag("Enemy"))
            {
                BaseHealth baseHealth = other.GetComponent<BaseHealth>();

                if (baseHealth != null)
                {
                    Vector3 pos = collisionEvents[i].intersection;
                    Vector3 force = collisionEvents[i].velocity;// * 10;
                    rb.AddForce(force);
                    baseHealth.TakeDamage(attackValue);
                }
            }
            i++;
        }
    }

    void Update()
    {
        var collision = ps.collision;
        collision.maxKillSpeed = particleSpeed;

        Debug.Log("Particles Alive Count: " + GetAliveParticles());

        ps.Emit(maxParticles);
        var main = ps.main;
        main.maxParticles = Mathf.RoundToInt(maxParticles);
        main.startLifetime = particleLife;

        if (neverDies)
        {
            particleLife = float.PositiveInfinity;
        }
        else
        {
            particleLife = 5f;
        }
    }



    int GetAliveParticles()
    {
        ParticleSystem.Particle[] particles = new ParticleSystem.Particle[ps.particleCount];
        return ps.GetParticles(particles);
    }
}

Answer 1

I solved the problem.

1. The ps was missing a render material. Apparently this prevents the collisions to be detected.
2. I activated Send Collision Messages in the Collision Module, without that it won't work.

Thanks all.