Version: 2020.2
  • C#


Suggest a change


Thank you for helping us improve the quality of Unity Documentation. Although we cannot accept all submissions, we do read each suggested change from our users and will make updates where applicable.


Submission failed

For some reason your suggested change could not be submitted. Please <a>try again</a> in a few minutes. And thank you for taking the time to help us improve the quality of Unity Documentation.



Switch to Manual
public bool alphaAffectsIntensity;


Toggle whether the system multiplies the particle alpha by the light intensity when it computes the final light intensity.

This is useful to fade the Lights out at the same time as the particles, to avoid popping.

using UnityEngine;
using System.Collections;

// For best results, use Deferred Rendering (see Camera settings) public class ExampleClass : MonoBehaviour { private ParticleSystem ps; public Light lightPrefab; // Provide a light Prefab in the inspector (eg a default Point Light) public float hSliderValueA = 1.0f; public bool alphaAffectsIntensity = true;

void Start() { ps = GetComponent<ParticleSystem>(); ps.transform.localRotation = Quaternion.Euler(0.0f, 0.0f, 45.0f);

var shape = ps.shape; shape.shapeType = ParticleSystemShapeType.Circle;

var lights = ps.lights; lights.enabled = true; lights.light = lightPrefab; lights.ratio = 1.0f; lights.maxLights = 1000;

// plane to receive lights var plane = GameObject.CreatePrimitive(PrimitiveType.Plane); plane.transform.parent = ps.transform; plane.transform.localPosition = new Vector3(0.0f, 0.0f, 3.0f); plane.transform.localScale = new Vector3(20.0f, 20.0f, 20.0f); plane.transform.localRotation = Quaternion.Euler(-90.0f, 0.0f, 0.0f);

var material = new Material(Shader.Find("Standard")); material.color = new Color(0.1f, 0.1f, 0.1f, 1.0f); plane.GetComponent<MeshRenderer>().material = material; }

void Update() { var lights = ps.lights; lights.alphaAffectsIntensity = alphaAffectsIntensity;

var main = ps.main; main.startColor = new Color(1.0f, 1.0f, 1.0f, hSliderValueA); }

void OnGUI() { GUI.Label(new Rect(25, 40, 100, 30), "Alpha");

hSliderValueA = GUI.HorizontalSlider(new Rect(95, 45, 100, 30), hSliderValueA, 0.0f, 1.0f); alphaAffectsIntensity = GUI.Toggle(new Rect(25, 85, 200, 30), alphaAffectsIntensity, "Particle Alpha Affects Light Intensity"); } }