Version: 2017.2
public float xMultiplier ;

Description

Speed multiplier along the X axis.

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

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { private ParticleSystem ps; public float hSliderValue = 1.0f;

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

var rotationBySpeed = ps.rotationBySpeed; rotationBySpeed.enabled = true; rotationBySpeed.separateAxes = true;

rotationBySpeed.xMultiplier = 1.0f; rotationBySpeed.yMultiplier = 0.0f; rotationBySpeed.zMultiplier = 0.0f; rotationBySpeed.range = new Vector2(1.0f, 5.0f);

var psr = GetComponent<ParticleSystemRenderer>(); psr.material = new Material(Shader.Find("Sprites/Default")); // this material renders a square billboard, so we can see the rotation }

void Update() { var main = ps.main; main.startSpeed = hSliderValue; }

void OnGUI() { hSliderValue = GUI.HorizontalSlider(new Rect(25, 45, 100, 30), hSliderValue, 1.0f, 5.0f); } }