유니티 파티클 이펙트 사이즈 변경 코드

// This script will only work in editor mode. You cannot adjust the scale dynamically in-game!
using UnityEngine;
using System.Collections;

#if UNITY_EDITOR 
using UnityEditor;
#endif

[ExecuteInEditMode]
public class ParticleScaler : MonoBehaviour {
 public float particleScale = 1.0f;
 public bool alsoScaleGameobject = true;
 float prevScale;

 void Start() {
  prevScale = particleScale;
 }

 void Update() {
#if UNITY_EDITOR
  // check if we need to update
  if (prevScale != particleScale && particleScale > 0) {
   if (alsoScaleGameobject)
    transform.localScale = new Vector3(particleScale, particleScale, particleScale);

   float scaleFactor = particleScale / prevScale;

   // scale legacy particle systems
   ScaleLegacySystems(scaleFactor);

   // scale shuriken particle systems
   ScaleShurikenSystems(scaleFactor);

   // scale trail renders
   ScaleTrailRenderers(scaleFactor);

   prevScale = particleScale;
  }
#endif
 }

 void ScaleShurikenSystems(float scaleFactor) {
#if UNITY_EDITOR 
  // get all shuriken systems we need to do scaling on
  ParticleSystem[] systems = GetComponentsInChildren();

  foreach (ParticleSystem system in systems) {
   system.startSpeed *= scaleFactor;
   system.startSize *= scaleFactor;
   system.gravityModifier *= scaleFactor;

   // some variables cannot be accessed through regular script, we will acces them through a serialized object
   SerializedObject so = new SerializedObject(system);
   
   // unity 4.0 and onwards will already do this one for us
#if UNITY_3_5 
   so.FindProperty("ShapeModule.radius").floatValue *= scaleFactor;
   so.FindProperty("ShapeModule.boxX").floatValue *= scaleFactor;
   so.FindProperty("ShapeModule.boxY").floatValue *= scaleFactor;
   so.FindProperty("ShapeModule.boxZ").floatValue *= scaleFactor;
#endif
   
   so.FindProperty("VelocityModule.x.scalar").floatValue *= scaleFactor;
   so.FindProperty("VelocityModule.y.scalar").floatValue *= scaleFactor;
   so.FindProperty("VelocityModule.z.scalar").floatValue *= scaleFactor;
   so.FindProperty("ClampVelocityModule.magnitude.scalar").floatValue *= scaleFactor;
   so.FindProperty("ClampVelocityModule.x.scalar").floatValue *= scaleFactor;
   so.FindProperty("ClampVelocityModule.y.scalar").floatValue *= scaleFactor;
   so.FindProperty("ClampVelocityModule.z.scalar").floatValue *= scaleFactor;
   so.FindProperty("ForceModule.x.scalar").floatValue *= scaleFactor;
   so.FindProperty("ForceModule.y.scalar").floatValue *= scaleFactor;
   so.FindProperty("ForceModule.z.scalar").floatValue *= scaleFactor;
   so.FindProperty("ColorBySpeedModule.range").vector2Value *= scaleFactor;
   so.FindProperty("SizeBySpeedModule.range").vector2Value *= scaleFactor;
   so.FindProperty("RotationBySpeedModule.range").vector2Value *= scaleFactor;

   so.ApplyModifiedProperties();
  }
#endif
 }

 void ScaleLegacySystems(float scaleFactor) {
#if UNITY_EDITOR 
  // get all emitters we need to do scaling on
  ParticleEmitter[] emitters = GetComponentsInChildren();

  // get all animators we need to do scaling on
  ParticleAnimator[] animators = GetComponentsInChildren();

  // apply scaling to emitters
  foreach (ParticleEmitter emitter in emitters) {
   emitter.minSize *= scaleFactor;
   emitter.maxSize *= scaleFactor;
   emitter.worldVelocity *= scaleFactor;
   emitter.localVelocity *= scaleFactor;
   emitter.rndVelocity *= scaleFactor;

   // some variables cannot be accessed through regular script, we will acces them through a serialized object
   SerializedObject so = new SerializedObject(emitter);

   so.FindProperty("m_Ellipsoid").vector3Value *= scaleFactor;
   so.FindProperty("tangentVelocity").vector3Value *= scaleFactor;
   so.ApplyModifiedProperties();
  }

  // apply scaling to animators
  foreach (ParticleAnimator animator in animators) {
   animator.force *= scaleFactor;
   animator.rndForce *= scaleFactor;
  }
#endif
 }

 void ScaleTrailRenderers(float scaleFactor) {
  // get all animators we need to do scaling on
  TrailRenderer[] trails = GetComponentsInChildren();

  // apply scaling to animators
  foreach (TrailRenderer trail in trails) {
   trail.startWidth *= scaleFactor;
   trail.endWidth *= scaleFactor;
  }
 }
}

출처 :https://github.com/hypno2000/starcontrol/blob/master/Assets/ParticleScaler/ParticleScaler.cs