ParticleSystem.ExternalForcesModule.multiplier

Description

Multiplies the magnitude of external forces affecting the particles.

Changing this property is more efficient than accessing the entire curve, if you only want to change the overall force multiplier.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    private ParticleSystem ps;
    public bool moduleEnabled = true;
    public float hSliderValue = 10.0f;

    void Start()
    {
        ps = GetComponent<ParticleSystem>();

        GameObject wind = new GameObject("Wind", typeof(WindZone));
        wind.transform.parent = ps.transform;
        wind.transform.localPosition = new Vector3(-4.0f, 0.0f, 0.0f);
        wind.GetComponent<WindZone>().mode = WindZoneMode.Spherical;
    }

    void Update()
    {
        var externalForces = ps.externalForces;
        externalForces.enabled = moduleEnabled;
        externalForces.multiplier = hSliderValue;
    }

    void OnGUI()
    {
        moduleEnabled = GUI.Toggle(new Rect(25, 45, 100, 30), moduleEnabled, "Enabled");
        hSliderValue = GUI.HorizontalSlider(new Rect(25, 85, 100, 30), hSliderValue, 0.0f, 100.0f);
    }
}