Version: 2017.1
public float ratio ;

Description

Choose what proportion of particles will receive a trail.

Use a value between 0 and 1, where 0 will add trails to no particles, and 1 will add trails to all particles.

using UnityEngine;
using System.Collections;

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

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

var main = ps.main; main.startColor = new ParticleSystem.MinMaxGradient(Color.red, Color.yellow); main.startSize = 0.1f;

var trails = ps.trails; trails.enabled = true;

var psr = GetComponent<ParticleSystemRenderer>(); psr.trailMaterial = new Material(Shader.Find("Sprites/Default")); }

void Update() { var trails = ps.trails; trails.ratio = hSliderValueRatio; }

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

hSliderValueRatio = GUI.HorizontalSlider(new Rect(55, 45, 100, 30), hSliderValueRatio, 0.0f, 1.0f); } }