Set the rotation over lifetime on each axis separately.
When disabled, only the z-axis rotation curve is used.
using UnityEngine; using System.Collections;
[RequireComponent(typeof(ParticleSystem))] public class ExampleClass : MonoBehaviour { private ParticleSystem ps; public float hSliderValue = 1.0f;
void Start() { ps = GetComponent<ParticleSystem>();
var rotationOverLifetime = ps.rotationOverLifetime; rotationOverLifetime.enabled = true; rotationOverLifetime.separateAxes = true;
AnimationCurve curve = new AnimationCurve(); curve.AddKey(0.0f, 0.0f); curve.AddKey(1.0f, 1.0f);
rotationOverLifetime.x = new ParticleSystem.MinMaxCurve(Mathf.PI * 2.0f, curve); rotationOverLifetime.y = 0.0f; rotationOverLifetime.z = 0.0f;
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.startLifetime = hSliderValue; }
void OnGUI() { hSliderValue = GUI.HorizontalSlider(new Rect(25, 45, 100, 30), hSliderValue, 1.0f, 5.0f); } }