fix: when using mesh sharing, the Transform.scale of the primary UIParticle affects the replicas.

close #333

NOTE: This fix may cause changes in the rendering of existing UIParticles.

Assets/ProjectSettings/NanoMonitor.asset

@@ -31,3 +31,10 @@ MonoBehaviour:
       m_Path: UnityEngine.Screen, UnityEngine.CoreModule;height
     m_Arg2:
       m_Path: 
+  - m_Format: UIParticles:{0} Materials:{1}
+    m_Arg0:
+      m_Path: Coffee.UIExtensions.UIParticleUpdater, Coffee.UIParticle;uiParticleCount
+    m_Arg1:
+      m_Path: Coffee.UIParticleInternal.MaterialRepository, Coffee.UIParticle;count
+    m_Arg2:
+      m_Path: 

Packages/src/CHANGELOG.md

@@ -1,3 +1,10 @@
+## [4.9.1](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.9.0...v4.9.1) (2024-08-07)
+
+
+### Bug Fixes
+
+* ParticleSystem trails gain offset on parent canvas change ([2a1cd50](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/2a1cd502b452b5b56edf8bcfe91adf99d1bb5147)), closes [#323](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/323)
+
 # [4.9.0](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.8.1...v4.9.0) (2024-07-18)
 
 

Packages/src/Runtime/UIParticle.cs

@@ -355,13 +355,6 @@ namespace Coffee.UIExtensions
         {
         }
 
-        /// <summary>
-        /// This function is called when a direct or indirect parent of the transform of the GameObject has changed.
-        /// </summary>
-        protected override void OnTransformParentChanged()
-        {
-        }
-
         void ISerializationCallbackReceiver.OnBeforeSerialize()
         {
         }
@@ -593,7 +586,7 @@ namespace Coffee.UIExtensions
             }
         }
 
-        internal void UpdateTransformScale()
+        internal void UpdateTransformScale(Vector3 ratio)
         {
             _tracker.Clear();
             canvasScale = canvas.rootCanvas.transform.localScale.Inverse();
@@ -617,7 +610,7 @@ namespace Coffee.UIExtensions
             }
 
             _tracker.Add(this, rectTransform, DrivenTransformProperties.Scale);
-            var newScale = parentScale.Inverse();
+            var newScale = parentScale.GetScaled(ratio).Inverse();
             if (currentScale != newScale)
             {
                 transform.localScale = newScale;

Packages/src/Runtime/UIParticleUpdater.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using Coffee.UIParticleExtensions;
 using UnityEditor;
 using UnityEngine;
 
@@ -8,7 +9,7 @@ namespace Coffee.UIExtensions
     {
         private static readonly List<UIParticle> s_ActiveParticles = new List<UIParticle>();
         private static readonly List<UIParticleAttractor> s_ActiveAttractors = new List<UIParticleAttractor>();
-        private static readonly HashSet<int> s_UpdatedGroupIds = new HashSet<int>();
+        private static readonly Dictionary<int, Vector3> s_GroupScales = new Dictionary<int, Vector3>();
         private static int s_FrameCount;
 
         public static int uiParticleCount => s_ActiveParticles.Count;
@@ -53,14 +54,17 @@ namespace Coffee.UIExtensions
             // Do not allow it to be called in the same frame.
             if (s_FrameCount == Time.frameCount) return;
             s_FrameCount = Time.frameCount;
+            s_GroupScales.Clear();
 
             // Simulate -> Primary
             for (var i = 0; i < s_ActiveParticles.Count; i++)
             {
+                // Process only primary UIParticles.
                 var uip = s_ActiveParticles[i];
-                if (!uip || !uip.canvas || !uip.isPrimary || !s_UpdatedGroupIds.Add(uip.groupId)) continue;
+                if (!uip || !uip.canvas || !uip.isPrimary || s_GroupScales.ContainsKey(uip.groupId)) continue;
 
-                uip.UpdateTransformScale();
+                s_GroupScales.Add(uip.groupId, uip.transform.parent.lossyScale);
+                uip.UpdateTransformScale(Vector3.one);
                 uip.UpdateRenderers();
             }
 
@@ -70,20 +74,31 @@ namespace Coffee.UIExtensions
                 var uip = s_ActiveParticles[i];
                 if (!uip || !uip.canvas) continue;
 
-                uip.UpdateTransformScale();
+                // Case 1: Not using mesh sharing.
-
                 if (!uip.useMeshSharing)
                 {
+                    uip.UpdateTransformScale(Vector3.one);
                     uip.UpdateRenderers();
                 }
-                else if (s_UpdatedGroupIds.Add(uip.groupId))
+                // Case 2: Using mesh sharing as primary.
+                else if (!s_GroupScales.TryGetValue(uip.groupId, out var groupScale))
                 {
+                    s_GroupScales.Add(uip.groupId, uip.transform.parent.lossyScale);
+                    uip.UpdateTransformScale(Vector3.one);
                     uip.UpdateRenderers();
                 }
+                // Case 3: Using mesh sharing as replica. (Only scaling)
+                else
+                {
+                    var parentScale = uip.transform.parent.lossyScale;
+                    var ratio = parentScale.IsVisible()
+                        ? groupScale.GetScaled(parentScale.Inverse())
+                        : Vector3.one;
+                    ratio = Vector3.one;
+                    uip.UpdateTransformScale(ratio);
+                }
             }
 
-            s_UpdatedGroupIds.Clear();
-
             // Attract
             for (var i = 0; i < s_ActiveAttractors.Count; i++)
             {

Packages/src/package.json

@@ -2,7 +2,7 @@
   "name": "com.coffee.ui-particle",
   "displayName": "UI Particle",
   "description": "This package provides a component to render particle effects for uGUI.\nThe particle rendering is maskable and sortable, without the need for an extra Camera, RenderTexture, or Canvas.",
-  "version": "4.9.0",
+  "version": "4.9.1",
   "unity": "2018.2",
   "license": "MIT",
   "repository": {