chore(release): 4.7.2 [skip ci]

## [4.7.2](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.7.1...v4.7.2) (2024-06-21)

### Bug Fixes

* generated baking-camera object remains in the prefab or scene ([0bb8438](0bb8438301))

.github/FUNDING.yml

@@ -0,0 +1,12 @@
+# These are supported funding model platforms
+
+github: mob-sakai # Replace with up to 4 GitHub Sponsors-enabled usernames e.g., [user1, user2]
+patreon: mob_sakai # Replace with a single Patreon username
+open_collective: # Replace with a single Open Collective username
+ko_fi: # Replace with a single Ko-fi username
+tidelift: # Replace with a single Tidelift platform-name/package-name e.g., npm/babel
+community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
+liberapay: # Replace with a single Liberapay username
+issuehunt: # Replace with a single IssueHunt username
+otechie: # Replace with a single Otechie username
+custom: # Replace with up to 4 custom sponsorship URLs e.g., ['link1', 'link2']

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,35 @@
+---
+name: Bug report
+about: Create a report to help us improve
+title: ''
+labels: bug
+assignees: mob-sakai
+
+---
+
+NOTE: Your issue may already be reported! Please search on the [issue tracker](../) before creating one.
+
+**Describe the bug**
+A clear and concise description of what the bug is.
+
+**To Reproduce**
+Steps to reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**Expected behavior**
+A clear and concise description of what you expected to happen.
+
+**Screenshots**
+If applicable, add screenshots to help explain your problem.
+
+**Environment (please complete the following information):**
+ - Version [e.g. 4.0.0]
+ - Platform: [e.g. Editor(Windows/Mac), Standalone(Windows/Mac), iOS, Android, WebGL]
+ - Unity version: [e.g. 2022.3.0f1]
+ - Build options: [e.g. IL2CPP, .Net 4.x, LWRP]
+
+**Additional context**
+Add any other context about the problem here.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,22 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: ''
+labels: enhancement
+assignees: mob-sakai
+
+---
+
+NOTE: Your issue may already be reported! Please search on the [issue tracker](../) before creating one.
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

.github/ISSUE_TEMPLATE/question.md

@@ -0,0 +1,16 @@
+---
+name: Question
+about: Ask a question about this project
+title: ''
+labels: question
+assignees: mob-sakai
+
+---
+
+NOTE: Your issue may already be reported! Please search on the [issue tracker](../) before creating one.
+
+**Describe what help do you need**
+A description of the question.
+
+**Additional context**
+Add any other context or screenshots about the question here.

.github/pull_request_template.md

@@ -0,0 +1,9 @@
+---
+name: Pull Request
+about: Create a pull request
+title: ''
+assignees: mob-sakai
+
+---
+
+**NOTE: Create a pull request to merge into `develop` branch**

.releaserc.json

@@ -1,8 +1,9 @@
 {
   "branches": [
     "release",
+    "release-4.x",
     {
-      "name": "preview",
+      "name": "release-preview",
       "prerelease": true
     }
   ],

CHANGELOG.md

@@ -1,3 +1,78 @@
+## [4.7.2](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.7.1...v4.7.2) (2024-06-21)
+
+
+### Bug Fixes
+
+* generated baking-camera object remains in the prefab or scene ([0bb8438](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/0bb843830197d8c1252232928becc211c0ada08d))
+
+## [4.7.1](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.7.0...v4.7.1) (2024-06-20)
+
+
+### Bug Fixes
+
+* despite not using the size module, particles become smaller based on their z position ([a8ed6e6](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/a8ed6e68584e1d9e45ed852eefcc03979ea7e0e1)), closes [#316](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/316)
+
+# [4.7.0](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.6.8...v4.7.0) (2024-06-19)
+
+
+### Bug Fixes
+
+* `UIParticle.transform.localScale` does not scale particles ([1d40e24](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/1d40e24c742741e97f03c55468ccb1e505341133)), closes [#313](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/313)
+* UIParticle is scaled by canvas size even when `AutoScalingMode.None` and `ScalingMode.Local` ([54a4b1c](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/54a4b1cdfd06400c7be89c1ee704bb42a659c7c2)), closes [#313](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/313)
+* UIParticle is scaled incorrectly with nested canvases ([f26920f](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/f26920f9825547222a4afbb31cc5dc5a002c3e9b)), closes [#313](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/313)
+
+
+### Features
+
+* reset previous position on start play for world space simulation ([3880484](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/3880484ce5190c42fc79c81d0b69e3fbeda09dd0)), closes [#303](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/303)
+* restore `Transform.localScale` when setting `autoScalingMode` to something other than `Transform` ([5505247](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/5505247a94a929ff89635fde512a9b95691e0043))
+
+## [4.6.8](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.6.7...v4.6.8) (2024-06-14)
+
+
+### Bug Fixes
+
+* 'Resource ID out of range in GetResource' error in overlay rendering mode ([05286ce](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/05286cedfd17b1a0cb90a5e918513644f47cd831)), closes [#308](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/308)
+
+## [4.6.7](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.6.6...v4.6.7) (2024-05-24)
+
+
+### Bug Fixes
+
+* the ParticleSystem's localPosition drifts at certain scales due to floating-point precision issues ([e924eb4](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/e924eb45968a112347471cabaeabc274e4c37ce4)), closes [#299](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/299) [#312](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/312)
+
+## [4.6.6](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.6.5...v4.6.6) (2024-05-23)
+
+
+### Bug Fixes
+
+* fix release workflow ([30b0076](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/30b00762f6da166c043587798b1552f27b4cc604))
+
+## [4.6.5](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.6.4...v4.6.5) (2024-05-23)
+
+
+### Bug Fixes
+
+* update workflows (for preview and v4) ([3eab097](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/3eab0979b9b85919b804442ab05735b7120eade5))
+
+## [4.6.4](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.6.3...v4.6.4) (2024-05-22)
+
+
+### Bug Fixes
+
+* assertion failed on expression: 'ps->array_size()' ([1b5c359](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/1b5c359058289895caf5f245fe09abb643bc38eb)), closes [#278](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/278)
+* lost Material.mainTexture when using AnimatableProperties ([ea04352](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/ea043524c0b00f67cba26a1f9ea537ee4a56d6ff)), closes [#311](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/311)
+* remove unnecessary code ([c37c014](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/c37c01486499773e3d7e8296c95bb4c3fae94abb))
+
+## [4.6.3](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.6.2...v4.6.3) (2024-04-04)
+
+
+### Bug Fixes
+
+* if only Trail Material is used, it will not be displayed ([2eff411](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/2eff411bd97eb4e6947d29a02b85b414bfdaee3a)), closes [#294](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/294)
+* if the UIParticle parents do not have Canvas, an exception is thrown in OnEnable ([e82c833](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/e82c833d04b819f103984931ba29a3616ef50908)), closes [#300](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/300)
+* particle size too small due to auto scaling ([2ec3748](https://github.com/mob-sakai/ParticleEffectForUGUI/commit/2ec374833614d64406e7c3207ca5fe234a749dcb)), closes [#295](https://github.com/mob-sakai/ParticleEffectForUGUI/issues/295)
+
 ## [4.6.2](https://github.com/mob-sakai/ParticleEffectForUGUI/compare/v4.6.1...v4.6.2) (2024-02-01)
 
 

Editor/UIParticleEditor.cs

@@ -475,20 +475,7 @@ namespace Coffee.UIExtensions
 
         private static void DrawAutoScaling(SerializedProperty prop, IEnumerable<UIParticle> uiParticles)
         {
-            var isTransformMode = prop.intValue == (int)UIParticle.AutoScalingMode.Transform;
-            EditorGUI.BeginChangeCheck();
             EditorGUILayout.PropertyField(prop);
-            if (!EditorGUI.EndChangeCheck() || !isTransformMode) return;
-
-            // on changed true->false, reset scale.
-            EditorApplication.delayCall += () =>
-            {
-                foreach (var uip in uiParticles)
-                {
-                    if (!uip) continue;
-                    uip.transform.localScale = Vector3.one;
-                }
-            };
         }
 
 #if UNITY_2021_2_OR_NEWER

LICENSE.md

@@ -1,4 +1,4 @@
-Copyright 2018-2023 mob-sakai
+Copyright 2018-2024 mob-sakai
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

Runtime/ModifiedMaterial.cs

@@ -29,7 +29,7 @@ namespace Coffee.UIParticleExtensions
                 {
                     name = $"{baseMat.name}_{id}",
                     hideFlags = HideFlags.DontSave | HideFlags.NotEditable,
-                    mainTexture = texture ? texture : null
+                    mainTexture = texture ? texture : baseMat.mainTexture
                 }
             };
             s_Entries.Add(e);

Runtime/UIParticle.cs

@@ -2,7 +2,6 @@ using System;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 using Coffee.UIParticleExtensions;
-using UnityEditor;
 using UnityEngine;
 using UnityEngine.Rendering;
 using UnityEngine.Serialization;
@@ -100,13 +99,12 @@ namespace Coffee.UIExtensions
                  "UIParticle: UIParticle.scale will be adjusted.")]
         private AutoScalingMode m_AutoScalingMode = AutoScalingMode.Transform;
 
-        [SerializeField]
-        private bool m_ResetScaleOnEnable;
-
         private readonly List<UIParticleRenderer> _renderers = new List<UIParticleRenderer>();
         private int _groupId;
-        private Camera _orthoCamera;
+        private Camera _bakeCamera;
         private DrivenRectTransformTracker _tracker;
+        private Vector3 _storedScale;
+        private bool _isScaleStored;
 
         /// <summary>
         /// Should this graphic be considered a target for ray-casting?
@@ -204,7 +202,12 @@ namespace Coffee.UIExtensions
             {
                 if (m_AutoScalingMode == value) return;
                 m_AutoScalingMode = value;
-                UpdateTracker();
+
+                if (autoScalingMode != AutoScalingMode.Transform && _isScaleStored)
+                {
+                    transform.localScale = _storedScale;
+                    _isScaleStored = false;
+                }
             }
         }
 
@@ -247,9 +250,9 @@ namespace Coffee.UIExtensions
         /// <summary>
         /// Particle effect scale.
         /// </summary>
-        public Vector3 scale3DForCalc => autoScalingMode == AutoScalingMode.UIParticle
-            ? m_Scale3D.GetScaled(canvasScale)
-            : m_Scale3D;
+        public Vector3 scale3DForCalc => autoScalingMode == AutoScalingMode.Transform
+            ? m_Scale3D
+            : m_Scale3D.GetScaled(canvasScale, transform.localScale);
 
         public List<ParticleSystem> particles => m_Particles;
 
@@ -282,8 +285,8 @@ namespace Coffee.UIExtensions
 
         protected override void OnEnable()
         {
+            _isScaleStored = false;
             ResetGroupId();
-            UpdateTracker();
             UIParticleUpdater.Register(this);
             RegisterDirtyMaterialCallback(UpdateRendererMaterial);
 
@@ -297,13 +300,6 @@ namespace Coffee.UIExtensions
             }
 
             base.OnEnable();
-
-            // Reset scale for upgrade.
-            if (m_ResetScaleOnEnable)
-            {
-                m_ResetScaleOnEnable = false;
-                transform.localScale = Vector3.one;
-            }
         }
 
         /// <summary>
@@ -311,7 +307,13 @@ namespace Coffee.UIExtensions
         /// </summary>
         protected override void OnDisable()
         {
-            UpdateTracker();
+            _tracker.Clear();
+            if (autoScalingMode == AutoScalingMode.Transform && _isScaleStored)
+            {
+                transform.localScale = _storedScale;
+            }
+
+            _isScaleStored = false;
             UIParticleUpdater.Unregister(this);
             _renderers.ForEach(r => r.Reset());
             UnregisterDirtyMaterialCallback(UpdateRendererMaterial);
@@ -326,14 +328,6 @@ namespace Coffee.UIExtensions
         {
         }
 
-#if UNITY_EDITOR
-        protected override void OnValidate()
-        {
-            base.OnValidate();
-            UpdateTracker();
-        }
-#endif
-
         void ISerializationCallbackReceiver.OnBeforeSerialize()
         {
         }
@@ -345,17 +339,6 @@ namespace Coffee.UIExtensions
                 m_IgnoreCanvasScaler = false;
                 m_AutoScaling = false;
                 m_AutoScalingMode = AutoScalingMode.Transform;
-                m_ResetScaleOnEnable = true;
-
-#if UNITY_EDITOR
-                EditorApplication.delayCall += () =>
-                {
-                    if (!this || !gameObject || !transform || Application.isPlaying) return;
-                    transform.localScale = Vector3.one;
-                    m_ResetScaleOnEnable = false;
-                    EditorUtility.SetDirty(this);
-                };
-#endif
             }
 
             if (m_AbsoluteMode)
@@ -503,12 +486,26 @@ namespace Coffee.UIExtensions
 
         internal void UpdateTransformScale()
         {
+            _tracker.Clear();
             canvasScale = canvas.rootCanvas.transform.localScale.Inverse();
             parentScale = transform.parent.lossyScale;
-            if (autoScalingMode != AutoScalingMode.Transform) return;
+            if (autoScalingMode != AutoScalingMode.Transform)
+            {
+                if (_isScaleStored)
+                {
+                    transform.localScale = _storedScale;
+                }
 
+                _isScaleStored = false;
+                return;
+            }
+
+            var currentScale = transform.localScale;
+            _storedScale = currentScale;
+            _isScaleStored = true;
+            _tracker.Add(this, rectTransform, DrivenTransformProperties.Scale);
             var newScale = parentScale.Inverse();
-            if (transform.localScale != newScale)
+            if (currentScale != newScale)
             {
                 transform.localScale = newScale;
             }
@@ -584,64 +581,46 @@ namespace Coffee.UIExtensions
         private Camera GetBakeCamera()
         {
             if (!canvas) return Camera.main;
+            if (_bakeCamera) return _bakeCamera;
 
-            // When render mode is ScreenSpaceCamera or WorldSpace, use world camera.
-            var root = canvas.rootCanvas;
-            if (root.renderMode != RenderMode.ScreenSpaceOverlay)
+            // Find existing baking camera.
+            var childCount = transform.childCount;
+            for (var i = 0; i < childCount; i++)
             {
-                return root.worldCamera ? root.worldCamera : Camera.main;
-            }
-
-            // When render mode is ScreenSpaceOverlay, use ortho-camera.
-            if (!_orthoCamera)
-            {
-                // Find existing ortho-camera.
-                foreach (Transform child in transform)
+                if (transform.GetChild(i).TryGetComponent<Camera>(out var cam)
+                    && cam.name == "[generated] UIParticle BakingCamera")
                 {
-                    var cam = child.GetComponent<Camera>();
-                    if (cam && cam.name == "[generated] UIParticleOverlayCamera")
-                    {
-                        _orthoCamera = cam;
-                        break;
-                    }
-                }
-
-                // Create ortho-camera.
-                if (!_orthoCamera)
-                {
-                    var go = new GameObject("[generated] UIParticleOverlayCamera")
-                    {
-                        hideFlags = HideFlags.HideAndDontSave
-                    };
-                    go.SetActive(false);
-                    go.transform.SetParent(transform, false);
-                    _orthoCamera = go.AddComponent<Camera>();
-                    _orthoCamera.enabled = false;
+                    _bakeCamera = cam;
+                    break;
                 }
             }
 
-            //
-            var size = ((RectTransform)root.transform).rect.size;
-            _orthoCamera.orthographicSize = Mathf.Max(size.x, size.y) * root.scaleFactor;
-            _orthoCamera.transform.SetPositionAndRotation(new Vector3(0, 0, -1000), Quaternion.identity);
-            _orthoCamera.orthographic = true;
-            _orthoCamera.farClipPlane = 2000f;
-
-            return _orthoCamera;
-        }
-
-        private void UpdateTracker()
-        {
-#pragma warning disable CS0618 // Type or member is obsolete
-            if (!enabled || !autoScaling || autoScalingMode != AutoScalingMode.Transform)
-#pragma warning restore CS0618 // Type or member is obsolete
+            // Create baking camera.
+            if (!_bakeCamera)
             {
-                _tracker.Clear();
-            }
-            else
-            {
-                _tracker.Add(this, rectTransform, DrivenTransformProperties.Scale);
+                var go = new GameObject("[generated] UIParticle BakingCamera")
+                {
+                    hideFlags = HideFlags.HideAndDontSave
+                };
+                go.SetActive(false);
+                go.transform.SetParent(transform, false);
+                _bakeCamera = go.AddComponent<Camera>();
             }
+
+            // Setup baking camera.
+            _bakeCamera.enabled = false;
+            _bakeCamera.orthographicSize = 1000;
+            _bakeCamera.transform.SetPositionAndRotation(new Vector3(0, 0, -1000), Quaternion.identity);
+            _bakeCamera.orthographic = true;
+            _bakeCamera.farClipPlane = 2000f;
+            _bakeCamera.clearFlags = CameraClearFlags.Nothing;
+            _bakeCamera.cullingMask = 0; // Nothing
+            _bakeCamera.allowHDR = false;
+            _bakeCamera.allowMSAA = false;
+            _bakeCamera.renderingPath = RenderingPath.Forward;
+            _bakeCamera.useOcclusionCulling = false;
+
+            return _bakeCamera;
         }
     }
 }

Runtime/UIParticleRenderer.cs

@@ -39,6 +39,7 @@ namespace Coffee.UIExtensions
         private float _prevCanvasScale;
         private Vector3 _prevPsPos;
         private Vector3 _prevScale;
+        private bool _isPrevStored;
         private Vector2Int _prevScreenSize;
         private bool _prewarm;
         private ParticleSystemRenderer _renderer;
@@ -146,6 +147,7 @@ namespace Coffee.UIExtensions
             ModifiedMaterial.Remove(_modifiedMaterial);
             _modifiedMaterial = null;
             _currentMaterialForRendering = null;
+            _isPrevStored = false;
         }
 
         public static UIParticleRenderer AddRenderer(UIParticle parent, int index)
@@ -328,7 +330,16 @@ namespace Coffee.UIExtensions
 
             // Bake mesh.
             Profiler.BeginSample("[UIParticleRenderer] Bake Mesh");
-            if (_isTrail && _parent.canSimulate && 0 < s_CombineInstances[0].mesh.vertexCount)
+            s_CombineInstances[0].mesh.Clear(false);
+
+            // Assertion failed on expression: 'ps->array_size()' #278
+            var extends = s_CombineInstances[0].mesh.bounds.extents.x;
+            if (!float.IsNaN(extends) && !float.IsInfinity(extends) && 0 < extends)
+            {
+                s_CombineInstances[0].mesh.RecalculateBounds();
+            }
+
+            if (_isTrail && _parent.canSimulate && 0 < _particleSystem.particleCount)
             {
 #if PS_BAKE_API_V2
                 _renderer.BakeTrailsMesh(s_CombineInstances[0].mesh, bakeCamera,
@@ -337,7 +348,7 @@ namespace Coffee.UIExtensions
                 _renderer.BakeTrailsMesh(s_CombineInstances[0].mesh, bakeCamera, true);
 #endif
             }
-            else if (_renderer.CanBakeMesh())
+            else if (!_isTrail && _renderer.CanBakeMesh())
             {
                 _particleSystem.ValidateShape();
 #if PS_BAKE_API_V2
@@ -347,15 +358,10 @@ namespace Coffee.UIExtensions
                 _renderer.BakeMesh(s_CombineInstances[0].mesh, bakeCamera, true);
 #endif
             }
-            else
-            {
-                s_CombineInstances[0].mesh.Clear(false);
-            }
 
             // Too many vertices to render.
             if (65535 <= s_CombineInstances[0].mesh.vertexCount)
             {
-                s_CombineInstances[0].mesh.Clear(false);
                 Debug.LogErrorFormat(this,
                     "Too many vertices to render. index={0}, isTrail={1}, vertexCount={2}(>=65535)",
                     _index,
@@ -517,9 +523,10 @@ namespace Coffee.UIExtensions
             var scale = _parent.scale3DForCalc.GetScaled(_parent.parentScale);
 
             if (_parent.autoScalingMode == UIParticle.AutoScalingMode.UIParticle
-                && _particleSystem.main.scalingMode == ParticleSystemScalingMode.Local)
+                && _particleSystem.main.scalingMode == ParticleSystemScalingMode.Local
+                && _parent.canvas)
             {
-                scale = scale.GetScaled(_parent.canvas.transform.localScale);
+                scale = scale.GetScaled(_parent.canvas.rootCanvas.transform.localScale);
             }
 
             Profiler.EndSample();
@@ -576,7 +583,7 @@ namespace Coffee.UIExtensions
             var isWorldSpace = _particleSystem.IsWorldSpace();
             var canvasScale = _parent.canvas ? _parent.canvas.scaleFactor : 1f;
             var resolutionChanged = _prevScreenSize != screenSize || _prevCanvasScale != canvasScale;
-            if (resolutionChanged && isWorldSpace)
+            if (resolutionChanged && isWorldSpace && _isPrevStored)
             {
                 // Update particle array size and get particles.
                 var size = _particleSystem.particleCount;
@@ -602,6 +609,7 @@ namespace Coffee.UIExtensions
                 _delay = true;
                 _prevScale = scale;
                 _prevPsPos = psPos;
+                _isPrevStored = true;
             }
 
             _prevCanvasScale = canvas ? canvas.scaleFactor : 1f;
@@ -627,13 +635,15 @@ namespace Coffee.UIExtensions
             // get world position.
             var isLocalSpace = _particleSystem.IsLocalSpace();
             var psTransform = _particleSystem.transform;
+            var originLocalPosition = psTransform.localPosition;
+            var originLocalRotation = psTransform.localRotation;
             var originWorldPosition = psTransform.position;
             var originWorldRotation = psTransform.rotation;
             var emission = _particleSystem.emission;
             var rateOverDistance = emission.enabled
                                    && 0 < emission.rateOverDistance.constant
                                    && 0 < emission.rateOverDistanceMultiplier;
-            if (rateOverDistance && !paused)
+            if (rateOverDistance && !paused && _isPrevStored)
             {
                 // (For rate-over-distance emission,) Move to previous scaled position, simulate (delta = 0).
                 var prevScaledPos = isLocalSpace
@@ -649,7 +659,8 @@ namespace Coffee.UIExtensions
                 : originWorldPosition.GetScaled(scale.Inverse());
             psTransform.SetPositionAndRotation(scaledPos, originWorldRotation);
             _particleSystem.Simulate(deltaTime, false, false, false);
-            psTransform.SetPositionAndRotation(originWorldPosition, originWorldRotation);
+            psTransform.localPosition = originLocalPosition;
+            psTransform.localRotation = originLocalRotation;
         }
 
 #if UNITY_EDITOR

Runtime/UIParticleUpdater.cs

@@ -57,9 +57,8 @@ namespace Coffee.UIExtensions
             for (var i = 0; i < s_ActiveParticles.Count; i++)
             {
                 var uip = s_ActiveParticles[i];
-                if (!uip || !uip.canvas || !uip.isPrimary || s_UpdatedGroupIds.Contains(uip.groupId)) continue;
+                if (!uip || !uip.canvas || !uip.isPrimary || !s_UpdatedGroupIds.Add(uip.groupId)) continue;
 
-                s_UpdatedGroupIds.Add(uip.groupId);
                 uip.UpdateTransformScale();
                 uip.UpdateRenderers();
             }
@@ -76,9 +75,8 @@ namespace Coffee.UIExtensions
                 {
                     uip.UpdateRenderers();
                 }
-                else if (!s_UpdatedGroupIds.Contains(uip.groupId))
+                else if (s_UpdatedGroupIds.Add(uip.groupId))
                 {
-                    s_UpdatedGroupIds.Add(uip.groupId);
                     uip.UpdateRenderers();
                 }
             }

Samples~/Demo/UIParticle_Demo.unity

@@ -14461,7 +14461,7 @@ Canvas:
   m_GameObject: {fileID: 1074082869}
   m_Enabled: 1
   serializedVersion: 3
-  m_RenderMode: 0
+  m_RenderMode: 1
   m_Camera: {fileID: 1023393581}
   m_PlaneDistance: 100
   m_PixelPerfect: 0

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": "4.6.2",
+  "version": "4.7.2",
   "unity": "2018.2",
   "license": "MIT",
   "repository": {