Version: 2019.1
public float startSizeZMultiplier ;

Description

The initial size multiplier of particles along the Z axis when emitted.

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

using UnityEngine;
using System.Collections;

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

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

var main = ps.main; main.startSize3D = true;

var psr = GetComponent<ParticleSystemRenderer>(); psr.renderMode = ParticleSystemRenderMode.Mesh; psr.mesh = Resources.GetBuiltinResource<Mesh>("Cube.fbx");// use a mesh, because billboards have no Z axis size psr.material = new Material(Shader.Find("Sprites/Default")); }

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

void OnGUI() { hSliderValue = GUI.HorizontalSlider(new Rect(25, 45, 100, 30), hSliderValue, 0.0F, 10.0F); } }