ParticleSystem.EmissionModule.rateOverDistanceMultiplier

Description

Change the rate over distance multiplier.

This is more efficient than accessing the whole curve, if you only want to change the overall rate multiplier.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    private ParticleSystem ps;
    public float hSliderValue = 5.0f;

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

        var main = ps.main;
        main.simulationSpace = ParticleSystemSimulationSpace.World;

        var shape = ps.shape;
        shape.enabled = false;

        var emission = ps.emission;
        emission.rateOverTime = 0.0f;

        // add a sphere so we can see our transform position as it moves
        var sphere = GameObject.CreatePrimitive(PrimitiveType.Sphere);
        sphere.transform.parent = ps.transform;
    }

    void Update()
    {
        var emission = ps.emission;
        emission.rateOverDistanceMultiplier = hSliderValue;

        ps.transform.position = new Vector3(Mathf.Sin(Time.time) * 2.0f, 0.0f, 0.0f);
    }

    void OnGUI()
    {
        hSliderValue = GUI.HorizontalSlider(new Rect(25, 45, 100, 30), hSliderValue, 1.0f, 20.0f);
    }
}