Version: 2019.1
public ParticleSystem.MinMaxCurve startRotation ;

Description

The initial rotation of particles when emitted.

Note that the value should be given in radians. See Also: MinMaxCurve.

using UnityEngine;
using System.Collections;

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

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

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.startRotation = hSliderValue; }

void OnGUI() { hSliderValue = GUI.HorizontalSlider(new Rect(25, 45, 100, 30), hSliderValue, 0.0F, 360.0F * Mathf.Deg2Rad); } }