I am trying to implement a magnetic field with particle system...

Questions & Answers
1

Though I managed to implement it with random objects( I expanded their collider, made it a trigger and transformed the objects), I can not find how to trigger the particles, since there is not an onTrigger option (there is also not an option where you can expand the collider of the particles and make it a trigger)

2

I’m not exactly sure what you want to achieve but I once wrote a particle attractor whitch attracts particles to a specific point. The class looks like this, maybe you can use something of it. It basically grabs the particles of a particle system and then manually changes their position based on their lifetime.

using UnityEngine;
using System.Collections;

public class ParticleAttractor : MonoBehaviour {
	
	[SerializeField]
	private Transform _attractorTransform;

	private ParticleSystem _particleSystem;
	private ParticleSystem.Particle[] _particles = new ParticleSystem.Particle[1000];

	public override void Start ()
	{
		_particleSystem = GetComponent<ParticleSystem> ();
	}

	public void LateUpdate()
	{
		if (particleSystem.isPlaying) {
			int length = _particleSystem.GetParticles (_particles);
			Vector3 attractorPosition = _attractorTransform.position;

			for (int i=0; i < length; i++) {
					_particles <em>.position = _particles <em>.position + (attractorPosition - _particles <em>.position) / (_particles _.lifetime) * Time.deltaTime;_</em></em></em>

* }*
* particleSystem.SetParticles (particles, length);*
* }*

* }*
}