public ParticleSystem.ExternalForcesModule externalForces ;


Script interface for the Particle System external forces module.

Particle system modules do not need to be reassigned back to the system; they are interfaces and not independent objects.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { void Start() { ParticleSystem ps = GetComponent<ParticleSystem>(); var ex = ps.externalForces; ex.enabled = true; ex.multiplier = 0.1f; } }