fix: incorrect handling of shape key deletion (#1258)

This change reworks delete handling to be more consistent with other properties, by treating it as a virtual property (`deletedShape.{blendshapeName}`) instead of a weird additional field of blendshape keys. This then fixes a number of issues (e.g. broken preview for delete keys). Fixes: #1253
2024-12-29 18:55:06 +08:00 · 2024-10-03 20:16:53 -07:00 · 2024-10-03 20:16:53 -07:00 · 30cafb21e4
commit 30cafb21e4
parent c379d730ca
13 changed files with 1040 additions and 102 deletions
--- a/Editor/ReactiveObjects/AnimationGeneration/AnimatedProperty.cs
+++ b/Editor/ReactiveObjects/AnimationGeneration/AnimatedProperty.cs
@ -8,7 +8,6 @@ namespace nadena.dev.modular_avatar.core.editor
        public TargetProp TargetProp { get; }
        public string ControlParam { get; set; }

-        public bool alwaysDeleted;
        public object currentState;

        // Objects which trigger deletion of this shape key. 
--- a/Editor/ReactiveObjects/AnimationGeneration/ReactionRule.cs
+++ b/Editor/ReactiveObjects/AnimationGeneration/ReactionRule.cs
@ -1,6 +1,5 @@
 using System.Collections.Generic;
 using System.Linq;
-using nadena.dev.modular_avatar.animation;
 using UnityEngine;

 namespace nadena.dev.modular_avatar.core.editor
@ -9,8 +8,8 @@ namespace nadena.dev.modular_avatar.core.editor
    {
        public ReactionRule(TargetProp key, float value)
            : this(key, (object)value) { }
-            
-        public  ReactionRule(TargetProp key, UnityEngine.Object value)
+
+        public ReactionRule(TargetProp key, Object value)
            : this(key, (object)value) { }
            
        private ReactionRule(TargetProp key, object value)
@ -31,15 +30,15 @@ namespace nadena.dev.modular_avatar.core.editor

        public bool InitiallyActive =>
            ((ControllingConditions.Count == 0) || ControllingConditions.All(c => c.InitiallyActive)) ^ Inverted;
-        public bool IsDelete;

        public bool Inverted;

        public bool IsConstant => ControllingConditions.Count == 0
                                  || ControllingConditions.All(c => c.IsConstant)
                                  || ControllingConditions.Any(c => c.IsConstant && !c.InitiallyActive);
-        public bool IsConstantOn => IsConstant && InitiallyActive;

+        public bool IsConstantActive => IsConstant && InitiallyActive ^ Inverted;
+        
        public override string ToString()
        {
            return $"AGK: {TargetProp}={Value}";
@ -57,7 +56,6 @@ namespace nadena.dev.modular_avatar.core.editor
            }
            else return false;
            if (!ControllingConditions.SequenceEqual(other.ControllingConditions)) return false;
-            if (IsDelete || other.IsDelete) return false;

            return true;
        }
--- a/Editor/ReactiveObjects/AnimationGeneration/ReactiveObjectAnalyzer.LocateReactions.cs
+++ b/Editor/ReactiveObjects/AnimationGeneration/ReactiveObjectAnalyzer.LocateReactions.cs
@ -124,50 +124,55 @@ namespace nadena.dev.modular_avatar.core.editor
                    var key = new TargetProp
                    {
                        TargetObject = renderer,
-                        PropertyName = "blendShape." + shape.ShapeName,
+                        PropertyName = BlendshapePrefix + shape.ShapeName
                    };

+                    var currentValue = renderer.GetBlendShapeWeight(shapeId);
                    var value = shape.ChangeType == ShapeChangeType.Delete ? 100 : shape.Value;
-                    if (!shapeKeys.TryGetValue(key, out var info))
+
+                    RegisterAction(key, renderer, currentValue, value, changer, shape);
+
+                    key = new TargetProp
                    {
-                        info = new AnimatedProperty(key, renderer.GetBlendShapeWeight(shapeId));
-                        shapeKeys[key] = info;
+                        TargetObject = renderer,
+                        PropertyName = DeletedShapePrefix + shape.ShapeName
+                    };

-                        // Add initial state
-                        var agk = new ReactionRule(key, value);
-                        agk.Value = renderer.GetBlendShapeWeight(shapeId);
-                        info.actionGroups.Add(agk);
-                    }
-
-                    var action = ObjectRule(key, changer, value);
-                    action.Inverted = _computeContext.Observe(changer, c => c.Inverted);
-                    var isCurrentlyActive = changer.gameObject.activeInHierarchy;
-
-                    if (shape.ChangeType == ShapeChangeType.Delete)
-                    {
-                        action.IsDelete = true;
-                        
-                        if (isCurrentlyActive) info.currentState = 100;
-
-                        info.actionGroups.Add(action); // Never merge
-
-                        continue;
-                    }
-
-                    if (changer.gameObject.activeInHierarchy) info.currentState = action.Value;
-
-                    if (info.actionGroups.Count == 0)
-                    {
-                        info.actionGroups.Add(action);
-                    }
-                    else if (!info.actionGroups[^1].TryMerge(action))
-                    {
-                        info.actionGroups.Add(action);
-                    }
+                    value = shape.ChangeType == ShapeChangeType.Delete ? 1 : 0;
+                    RegisterAction(key, renderer, 0, value, changer, shape);
                }
            }

            return shapeKeys;
+
+            void RegisterAction(TargetProp key, SkinnedMeshRenderer renderer, float currentValue, float value,
+                ModularAvatarShapeChanger changer, ChangedShape shape)
+            {
+                if (!shapeKeys.TryGetValue(key, out var info))
+                {
+                    info = new AnimatedProperty(key, currentValue);
+                    shapeKeys[key] = info;
+
+                    // Add initial state
+                    var agk = new ReactionRule(key, value);
+                    agk.Value = currentValue;
+                    info.actionGroups.Add(agk);
+                }
+
+                var action = ObjectRule(key, changer, value);
+                action.Inverted = _computeContext.Observe(changer, c => c.Inverted);
+
+                if (changer.gameObject.activeInHierarchy) info.currentState = action.Value;
+
+                if (info.actionGroups.Count == 0)
+                {
+                    info.actionGroups.Add(action);
+                }
+                else if (!info.actionGroups[^1].TryMerge(action))
+                {
+                    info.actionGroups.Add(action);
+                }
+            }
        }
        
        private void FindMaterialSetters(Dictionary<TargetProp, AnimatedProperty> objectGroups, GameObject root)
--- a/Editor/ReactiveObjects/AnimationGeneration/ReactiveObjectAnalyzer.cs
+++ b/Editor/ReactiveObjects/AnimationGeneration/ReactiveObjectAnalyzer.cs
@ -18,6 +18,9 @@ namespace nadena.dev.modular_avatar.core.editor
        private readonly ndmf.BuildContext _context;
        private readonly AnimationServicesContext _asc;
        private Dictionary<string, float> _simulationInitialStates;
+
+        public const string BlendshapePrefix = "blendShape.";
+        public const string DeletedShapePrefix = "deletedShape.";
        
        public ImmutableDictionary<string, float> ForcePropertyOverrides { get; set; } = ImmutableDictionary<string, float>.Empty;

@ -58,7 +61,6 @@ namespace nadena.dev.modular_avatar.core.editor
        {
            public Dictionary<TargetProp, AnimatedProperty> Shapes;
            public Dictionary<TargetProp, object> InitialStates;
-            public HashSet<TargetProp> DeletedShapes;
        }

        private static PropCache<GameObject, AnalysisResult> _analysisCache;
@ -86,7 +88,6 @@ namespace nadena.dev.modular_avatar.core.editor
        /// </summary>
        /// <param name="root">The avatar root</param>
        /// <param name="initialStates">A dictionary of target property to initial state (float or UnityEngine.Object)</param>
-        /// <param name="deletedShapes">A hashset of blendshape properties which are always deleted</param>
        /// <returns></returns>
        public AnalysisResult Analyze(
            GameObject root
@ -98,7 +99,6 @@ namespace nadena.dev.modular_avatar.core.editor
            {
                result.Shapes = new();
                result.InitialStates = new();
-                result.DeletedShapes = new();
                return result;
            }
            
@ -109,7 +109,7 @@ namespace nadena.dev.modular_avatar.core.editor
            ApplyInitialStateOverrides(shapes);
            AnalyzeConstants(shapes); 
            ResolveToggleInitialStates(shapes);
-            PreprocessShapes(shapes, out result.InitialStates, out result.DeletedShapes);
+            PreprocessShapes(shapes, out result.InitialStates);
            result.Shapes = shapes;

            return result;
@ -165,7 +165,7 @@ namespace nadena.dev.modular_avatar.core.editor
                group.actionGroups.RemoveAll(agk => agk.IsConstant && !agk.InitiallyActive);
                
                // Remove all action groups up until the last one where we're always on
-                var lastAlwaysOnGroup = group.actionGroups.FindLastIndex(ag => ag.IsConstantOn);
+                var lastAlwaysOnGroup = group.actionGroups.FindLastIndex(ag => ag.IsConstantActive);
                if (lastAlwaysOnGroup > 0)
                    group.actionGroups.RemoveRange(0, lastAlwaysOnGroup - 1);
            }
@ -264,18 +264,17 @@ namespace nadena.dev.modular_avatar.core.editor
        }

        /// <summary>
-        /// Determine initial state and deleted shapes for all properties
+        /// Determine initial state for all properties
        /// </summary>
        /// <param name="shapes"></param>
        /// <param name="initialStates"></param>
-        /// <param name="deletedShapes"></param>
-        private void PreprocessShapes(Dictionary<TargetProp, AnimatedProperty> shapes, out Dictionary<TargetProp, object> initialStates, out HashSet<TargetProp> deletedShapes)
+        private void PreprocessShapes(Dictionary<TargetProp, AnimatedProperty> shapes,
+            out Dictionary<TargetProp, object> initialStates)
        {
            // For each shapekey, determine 1) if we can just set an initial state and skip and 2) if we can delete the
            // corresponding mesh. If we can't, delete ops are merged into the main list of operations.
            
            initialStates = new Dictionary<TargetProp, object>();
-            deletedShapes = new HashSet<TargetProp>();

            foreach (var (key, info) in shapes.ToList())
            {
@ -285,18 +284,6 @@ namespace nadena.dev.modular_avatar.core.editor
                    shapes.Remove(key);
                    continue;
                }
-                
-                var deletions = info.actionGroups.Where(agk => agk.IsDelete).ToList();
-                if (deletions.Any(d => d.InitiallyActive))
-                {
-                    // always deleted
-                    shapes.Remove(key);
-                    deletedShapes.Add(key);
-                    continue;
-                }
-                
-                // Move deleted shapes to the end of the list, so they override all Set actions
-                info.actionGroups = info.actionGroups.Where(agk => !agk.IsDelete).Concat(deletions).ToList();

                var initialState = info.actionGroups.Where(agk => agk.InitiallyActive)
                    .Select(agk => agk.Value)
--- a/Editor/ReactiveObjects/AnimationGeneration/ReactiveObjectPass.cs
+++ b/Editor/ReactiveObjects/AnimationGeneration/ReactiveObjectPass.cs
@ -2,7 +2,6 @@

 using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Linq;
 using nadena.dev.modular_avatar.animation;
 using UnityEditor;
@ -42,10 +41,11 @@ namespace nadena.dev.modular_avatar.core.editor

            var shapes = analysis.Shapes;
            var initialStates = analysis.InitialStates;
-            var deletedShapes = analysis.DeletedShapes;
            
            GenerateActiveSelfProxies(shapes);

+            ProcessMeshDeletion(initialStates, shapes);
+
            ProcessInitialStates(initialStates, shapes);
            ProcessInitialAnimatorVariables(shapes);
            
@ -53,8 +53,6 @@ namespace nadena.dev.modular_avatar.core.editor
            {
                ProcessShapeKey(groups);
            }
-
-            ProcessMeshDeletion(deletedShapes);
        }

        private void GenerateActiveSelfProxies(Dictionary<TargetProp, AnimatedProperty> shapes)
@ -225,30 +223,65 @@ namespace nadena.dev.modular_avatar.core.editor

        #region Mesh processing

-        private void ProcessMeshDeletion(HashSet<TargetProp> deletedKeys)
+        private void ProcessMeshDeletion(Dictionary<TargetProp, object> initialStates,
+            Dictionary<TargetProp, AnimatedProperty> shapes)
        {
-            ImmutableDictionary<SkinnedMeshRenderer, List<TargetProp>> renderers = deletedKeys
-                .GroupBy(
-                    v => (SkinnedMeshRenderer) v.TargetObject
-                ).ToImmutableDictionary(
-                    g => (SkinnedMeshRenderer) g.Key,
-                    g => g.ToList()
-                );
+            var renderers = initialStates
+                .Where(kvp => kvp.Key.PropertyName.StartsWith(ReactiveObjectAnalyzer.DeletedShapePrefix))
+                .Where(kvp => kvp.Key.TargetObject is SkinnedMeshRenderer)
+                .Where(kvp => kvp.Value is float f && f > 0.5f)
+                // Filter any non-constant keys
+                .Where(kvp =>
+                {
+                    if (!shapes.ContainsKey(kvp.Key))
+                    {
+                        // Constant value
+                        return true;
+                    }

-            foreach (var (renderer, infos) in renderers)
+                    var lastGroup = shapes[kvp.Key].actionGroups.LastOrDefault();
+                    return lastGroup?.IsConstantActive == true && lastGroup.Value is float f && f > 0.5f;
+                })
+                .GroupBy(kvp => kvp.Key.TargetObject as SkinnedMeshRenderer)
+                .Select(grouping => (grouping.Key, grouping.Select(
+                    kvp => kvp.Key.PropertyName.Substring(ReactiveObjectAnalyzer.DeletedShapePrefix.Length)
+                ).ToList()))
+                .ToList();
+            foreach (var (renderer, shapeNamesToDelete) in renderers)
            {
                if (renderer == null) continue;

                var mesh = renderer.sharedMesh;
                if (mesh == null) continue;

-                renderer.sharedMesh = RemoveBlendShapeFromMesh.RemoveBlendshapes(
-                    mesh,
-                    infos
-                        .Select(i => mesh.GetBlendShapeIndex(i.PropertyName.Substring("blendShape.".Length)))
-                        .Where(k => k >= 0)
-                        .ToList()
-                );
+                var shapesToDelete = shapeNamesToDelete
+                    .Select(shape => mesh.GetBlendShapeIndex(shape))
+                    .Where(k => k >= 0)
+                    .ToList();
+
+                renderer.sharedMesh = RemoveBlendShapeFromMesh.RemoveBlendshapes(mesh, shapesToDelete);
+
+                foreach (var name in shapeNamesToDelete)
+                {
+                    // Don't need to animate this anymore...!
+                    shapes.Remove(new TargetProp
+                    {
+                        TargetObject = renderer,
+                        PropertyName = ReactiveObjectAnalyzer.BlendshapePrefix + name
+                    });
+
+                    shapes.Remove(new TargetProp
+                    {
+                        TargetObject = renderer,
+                        PropertyName = ReactiveObjectAnalyzer.DeletedShapePrefix + name
+                    });
+
+                    initialStates.Remove(new TargetProp
+                    {
+                        TargetObject = renderer,
+                        PropertyName = ReactiveObjectAnalyzer.BlendshapePrefix + name
+                    });
+                }
            }
        }

@ -257,10 +290,6 @@ namespace nadena.dev.modular_avatar.core.editor
        private void ProcessShapeKey(AnimatedProperty info)
        {
            // TODO: prune non-animated keys
-
-            // Check if this is non-animated and skip most processing if so
-            if (info.alwaysDeleted || info.actionGroups[^1].IsConstant) return;
-
            var asm = GenerateStateMachine(info);
            ApplyController(asm, "MA Responsive: " + info.TargetProp.TargetObject.name);
        }
--- a/Editor/ReactiveObjects/ShapeChangerPreview.cs
+++ b/Editor/ReactiveObjects/ShapeChangerPreview.cs
@ -72,8 +72,8 @@ namespace nadena.dev.modular_avatar.core.editor
            var analysis = ReactiveObjectAnalyzer.CachedAnalyze(context, avatarRoot);
            var shapes = analysis.Shapes;

-            ImmutableDictionary<SkinnedMeshRenderer, ImmutableList<(int, float)>>.Builder rendererStates =
-                ImmutableDictionary.CreateBuilder<SkinnedMeshRenderer, ImmutableList<(int, float)>>(
+            var rendererStates =
+                ImmutableDictionary.CreateBuilder<SkinnedMeshRenderer, ImmutableDictionary<int, float>>(
                    
                );
            var avatarRootTransform = avatarRoot.transform;
@ -83,16 +83,29 @@ namespace nadena.dev.modular_avatar.core.editor
                var target = prop.TargetProp;
                if (target.TargetObject == null || target.TargetObject is not SkinnedMeshRenderer r) continue;
                if (!r.transform.IsChildOf(avatarRootTransform)) continue;
-                if (!target.PropertyName.StartsWith("blendShape.")) continue;

+                var isDelete = false;
+                string shapeName = null;
+                if (target.PropertyName.StartsWith(ReactiveObjectAnalyzer.DeletedShapePrefix))
+                {
+                    isDelete = true;
+                    shapeName = target.PropertyName.Substring(ReactiveObjectAnalyzer.DeletedShapePrefix.Length);
+                }
+                else if (target.PropertyName.StartsWith(ReactiveObjectAnalyzer.BlendshapePrefix))
+                {
+                    shapeName = target.PropertyName.Substring(ReactiveObjectAnalyzer.BlendshapePrefix.Length);
+                }
+                else
+                {
+                    continue;
+                }
+                
                var mesh = r.sharedMesh;
                if (mesh == null) continue;
                
-                var shapeName = target.PropertyName.Substring("blendShape.".Length);
-                
                if (!rendererStates.TryGetValue(r, out var states))
                {
-                    states = ImmutableList<(int, float)>.Empty;
+                    states = ImmutableDictionary<int, float>.Empty;
                    rendererStates[r] = states;
                }
                
@ -103,15 +116,30 @@ namespace nadena.dev.modular_avatar.core.editor
                if (activeRule == null || activeRule.Value is not float value) continue;
                if (activeRule.ControllingObject == null) continue; // default value is being inherited

-                value = Math.Clamp(value, 0, 100);
-                
-                if (activeRule.IsDelete) value = -1;
-                
-                states = states.Add((index, value));
+                if (isDelete)
+                {
+                    if (value < 0.5f) continue;
+                    value = -1;
+                }
+                else
+                {
+                    if (states.ContainsKey(index))
+                    {
+                        // Delete takes precedence over set in preview
+                        continue;
+                    }
+
+                    value = Math.Clamp(value, 0, 100);
+                }
+
+                states = states.SetItem(index, value);
                rendererStates[r] = states;
            }
-            
-            return rendererStates.ToImmutableDictionary();
+
+            return rendererStates.ToImmutableDictionary(
+                kvp => kvp.Key,
+                kvp => kvp.Value.Select(shapePair => (shapePair.Key, shapePair.Value)
+                ).ToImmutableList());
        }
        
        private IEnumerable<RenderGroup> ShapesToGroups(GameObject avatarRoot, ImmutableDictionary<SkinnedMeshRenderer, ImmutableList<(int, float)>> shapes)
--- a/Editor/ReactiveObjects/Simulator/ROSimulator.cs
+++ b/Editor/ReactiveObjects/Simulator/ROSimulator.cs
@ -471,7 +471,7 @@ namespace nadena.dev.modular_avatar.core.editor.Simulator
                    var f_set_inactive = effectGroup.Q<VisualElement>("effect__set-inactive");
                    var f_value = effectGroup.Q<FloatField>("effect__value");
                    var f_material = effectGroup.Q<ObjectField>("effect__material");
-                    var f_delete = effectGroup.Q("effect__deleted");
+                    var f_delete = effectGroup.Q<TextField>("effect__deleted");
                    
                    f_target_component.style.display = DisplayStyle.None;
                    f_target_component.SetEnabled(false);
@ -504,9 +504,10 @@ namespace nadena.dev.modular_avatar.core.editor.Simulator
                        f_property.value = targetProp.PropertyName;
                        f_property.style.display = DisplayStyle.Flex;

-                        if (reactionRule.IsDelete)
+                        if (reactionRule.TargetProp.PropertyName.StartsWith(ReactiveObjectAnalyzer.DeletedShapePrefix))
                        {
                            f_delete.style.display = DisplayStyle.Flex;
+                            f_delete.value = reactionRule.Value is > 0.5f ? "DELETE" : "RETAIN";
                        } else if (reactionRule.Value is float f)
                        {
                            f_value.SetValueWithoutNotify(f);
--- a/UnitTests~/ReactiveComponent/DeletionTest.prefab
+++ b/UnitTests~/ReactiveComponent/DeletionTest.prefab
@ -0,0 +1,666 @@
+%YAML 1.1
+%TAG !u! tag:unity3d.com,2011:
+--- !u!1 &2464504760772767737
+GameObject:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  serializedVersion: 6
+  m_Component:
+  - component: {fileID: 3251791125987375227}
+  - component: {fileID: 6611954401356246169}
+  - component: {fileID: 4257580493320060063}
+  - component: {fileID: 7095484051158404692}
+  m_Layer: 0
+  m_Name: DeletionTest
+  m_TagString: Untagged
+  m_Icon: {fileID: 0}
+  m_NavMeshLayer: 0
+  m_StaticEditorFlags: 0
+  m_IsActive: 1
+--- !u!4 &3251791125987375227
+Transform:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 2464504760772767737}
+  serializedVersion: 2
+  m_LocalRotation: {x: 0, y: 0, z: 0, w: 1}
+  m_LocalPosition: {x: 0.06867766, y: 0.7869835, z: -0.57959247}
+  m_LocalScale: {x: 1, y: 1, z: 1}
+  m_ConstrainProportionsScale: 1
+  m_Children:
+  - {fileID: 8671858138418525756}
+  - {fileID: 3787319563290092876}
+  - {fileID: 2780879708549973278}
+  - {fileID: 6867583134219554799}
+  - {fileID: 3617623734196600728}
+  m_Father: {fileID: 0}
+  m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
+--- !u!95 &6611954401356246169
+Animator:
+  serializedVersion: 5
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 2464504760772767737}
+  m_Enabled: 1
+  m_Avatar: {fileID: 0}
+  m_Controller: {fileID: 0}
+  m_CullingMode: 0
+  m_UpdateMode: 0
+  m_ApplyRootMotion: 0
+  m_LinearVelocityBlending: 0
+  m_StabilizeFeet: 0
+  m_WarningMessage: 
+  m_HasTransformHierarchy: 1
+  m_AllowConstantClipSamplingOptimization: 1
+  m_KeepAnimatorStateOnDisable: 0
+  m_WriteDefaultValuesOnDisable: 0
+--- !u!114 &4257580493320060063
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 2464504760772767737}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 542108242, guid: 67cc4cb7839cd3741b63733d5adf0442, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  Name: 
+  ViewPosition: {x: 0, y: 1.6, z: 0.2}
+  Animations: 0
+  ScaleIPD: 1
+  lipSync: 0
+  lipSyncJawBone: {fileID: 0}
+  lipSyncJawClosed: {x: 0, y: 0, z: 0, w: 1}
+  lipSyncJawOpen: {x: 0, y: 0, z: 0, w: 1}
+  VisemeSkinnedMesh: {fileID: 0}
+  MouthOpenBlendShapeName: Facial_Blends.Jaw_Down
+  VisemeBlendShapes: []
+  unityVersion: 
+  portraitCameraPositionOffset: {x: 0, y: 0, z: 0}
+  portraitCameraRotationOffset: {x: 0, y: 1, z: 0, w: -0.00000004371139}
+  networkIDs: []
+  customExpressions: 0
+  expressionsMenu: {fileID: 0}
+  expressionParameters: {fileID: 0}
+  enableEyeLook: 0
+  customEyeLookSettings:
+    eyeMovement:
+      confidence: 0.5
+      excitement: 0.5
+    leftEye: {fileID: 0}
+    rightEye: {fileID: 0}
+    eyesLookingStraight:
+      linked: 1
+      left: {x: 0, y: 0, z: 0, w: 0}
+      right: {x: 0, y: 0, z: 0, w: 0}
+    eyesLookingUp:
+      linked: 1
+      left: {x: 0, y: 0, z: 0, w: 0}
+      right: {x: 0, y: 0, z: 0, w: 0}
+    eyesLookingDown:
+      linked: 1
+      left: {x: 0, y: 0, z: 0, w: 0}
+      right: {x: 0, y: 0, z: 0, w: 0}
+    eyesLookingLeft:
+      linked: 1
+      left: {x: 0, y: 0, z: 0, w: 0}
+      right: {x: 0, y: 0, z: 0, w: 0}
+    eyesLookingRight:
+      linked: 1
+      left: {x: 0, y: 0, z: 0, w: 0}
+      right: {x: 0, y: 0, z: 0, w: 0}
+    eyelidType: 0
+    upperLeftEyelid: {fileID: 0}
+    upperRightEyelid: {fileID: 0}
+    lowerLeftEyelid: {fileID: 0}
+    lowerRightEyelid: {fileID: 0}
+    eyelidsDefault:
+      upper:
+        linked: 1
+        left: {x: 0, y: 0, z: 0, w: 0}
+        right: {x: 0, y: 0, z: 0, w: 0}
+      lower:
+        linked: 1
+        left: {x: 0, y: 0, z: 0, w: 0}
+        right: {x: 0, y: 0, z: 0, w: 0}
+    eyelidsClosed:
+      upper:
+        linked: 1
+        left: {x: 0, y: 0, z: 0, w: 0}
+        right: {x: 0, y: 0, z: 0, w: 0}
+      lower:
+        linked: 1
+        left: {x: 0, y: 0, z: 0, w: 0}
+        right: {x: 0, y: 0, z: 0, w: 0}
+    eyelidsLookingUp:
+      upper:
+        linked: 1
+        left: {x: 0, y: 0, z: 0, w: 0}
+        right: {x: 0, y: 0, z: 0, w: 0}
+      lower:
+        linked: 1
+        left: {x: 0, y: 0, z: 0, w: 0}
+        right: {x: 0, y: 0, z: 0, w: 0}
+    eyelidsLookingDown:
+      upper:
+        linked: 1
+        left: {x: 0, y: 0, z: 0, w: 0}
+        right: {x: 0, y: 0, z: 0, w: 0}
+      lower:
+        linked: 1
+        left: {x: 0, y: 0, z: 0, w: 0}
+        right: {x: 0, y: 0, z: 0, w: 0}
+    eyelidsSkinnedMesh: {fileID: 0}
+    eyelidsBlendshapes: 
+  customizeAnimationLayers: 0
+  baseAnimationLayers:
+  - isEnabled: 0
+    type: 0
+    animatorController: {fileID: 0}
+    mask: {fileID: 0}
+    isDefault: 1
+  - isEnabled: 0
+    type: 4
+    animatorController: {fileID: 0}
+    mask: {fileID: 0}
+    isDefault: 1
+  - isEnabled: 0
+    type: 5
+    animatorController: {fileID: 0}
+    mask: {fileID: 0}
+    isDefault: 1
+  specialAnimationLayers:
+  - isEnabled: 0
+    type: 6
+    animatorController: {fileID: 0}
+    mask: {fileID: 0}
+    isDefault: 1
+  - isEnabled: 0
+    type: 7
+    animatorController: {fileID: 0}
+    mask: {fileID: 0}
+    isDefault: 1
+  - isEnabled: 0
+    type: 8
+    animatorController: {fileID: 0}
+    mask: {fileID: 0}
+    isDefault: 1
+  AnimationPreset: {fileID: 0}
+  animationHashSet: []
+  autoFootsteps: 1
+  autoLocomotion: 1
+  collider_head:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_torso:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_footR:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_footL:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_handR:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_handL:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_fingerIndexL:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_fingerMiddleL:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_fingerRingL:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_fingerLittleL:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_fingerIndexR:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_fingerMiddleR:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_fingerRingR:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+  collider_fingerLittleR:
+    isMirrored: 1
+    state: 0
+    transform: {fileID: 0}
+    radius: 0
+    height: 0
+    position: {x: 0, y: 0, z: 0}
+    rotation: {x: 0, y: 0, z: 0, w: 1}
+--- !u!114 &7095484051158404692
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 2464504760772767737}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: -1427037861, guid: 4ecd63eff847044b68db9453ce219299, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  launchedFromSDKPipeline: 0
+  completedSDKPipeline: 0
+  blueprintId: 
+  contentType: 0
+  assetBundleUnityVersion: 
+  fallbackStatus: 0
+--- !u!1 &3134446681435896768
+GameObject:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  serializedVersion: 6
+  m_Component:
+  - component: {fileID: 2780879708549973278}
+  - component: {fileID: 2470606632396626262}
+  m_Layer: 0
+  m_Name: Delete
+  m_TagString: Untagged
+  m_Icon: {fileID: 0}
+  m_NavMeshLayer: 0
+  m_StaticEditorFlags: 0
+  m_IsActive: 1
+--- !u!4 &2780879708549973278
+Transform:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 3134446681435896768}
+  serializedVersion: 2
+  m_LocalRotation: {x: 0, y: 0, z: 0, w: 1}
+  m_LocalPosition: {x: 0, y: 0, z: 0}
+  m_LocalScale: {x: 1, y: 1, z: 1}
+  m_ConstrainProportionsScale: 1
+  m_Children: []
+  m_Father: {fileID: 3251791125987375227}
+  m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
+--- !u!114 &2470606632396626262
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 3134446681435896768}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 2db441f589c3407bb6fb5f02ff8ab541, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  m_inverted: 0
+  m_shapes:
+  - Object:
+      referencePath: shape deletion test mesh
+      targetObject: {fileID: 0}
+    ShapeName: bottom
+    ChangeType: 0
+    Value: 50
+--- !u!1 &7874409458034691206
+GameObject:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  serializedVersion: 6
+  m_Component:
+  - component: {fileID: 3787319563290092876}
+  - component: {fileID: 8462455628590652122}
+  m_Layer: 0
+  m_Name: PriorSet
+  m_TagString: Untagged
+  m_Icon: {fileID: 0}
+  m_NavMeshLayer: 0
+  m_StaticEditorFlags: 0
+  m_IsActive: 1
+--- !u!4 &3787319563290092876
+Transform:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 7874409458034691206}
+  serializedVersion: 2
+  m_LocalRotation: {x: 0, y: 0, z: 0, w: 1}
+  m_LocalPosition: {x: 0, y: 0, z: 0}
+  m_LocalScale: {x: 1, y: 1, z: 1}
+  m_ConstrainProportionsScale: 1
+  m_Children: []
+  m_Father: {fileID: 3251791125987375227}
+  m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
+--- !u!114 &8462455628590652122
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 7874409458034691206}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 2db441f589c3407bb6fb5f02ff8ab541, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  m_inverted: 0
+  m_shapes:
+  - Object:
+      referencePath: shape deletion test mesh
+      targetObject: {fileID: 0}
+    ShapeName: bottom
+    ChangeType: 1
+    Value: 50
+--- !u!1 &7956182162252432618
+GameObject:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  serializedVersion: 6
+  m_Component:
+  - component: {fileID: 3617623734196600728}
+  - component: {fileID: 4167915178638071617}
+  - component: {fileID: 3280847981733507148}
+  m_Layer: 0
+  m_Name: MenuSet
+  m_TagString: Untagged
+  m_Icon: {fileID: 0}
+  m_NavMeshLayer: 0
+  m_StaticEditorFlags: 0
+  m_IsActive: 0
+--- !u!4 &3617623734196600728
+Transform:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 7956182162252432618}
+  serializedVersion: 2
+  m_LocalRotation: {x: 0, y: 0, z: 0, w: 1}
+  m_LocalPosition: {x: 0, y: 0, z: 0}
+  m_LocalScale: {x: 1, y: 1, z: 1}
+  m_ConstrainProportionsScale: 1
+  m_Children: []
+  m_Father: {fileID: 3251791125987375227}
+  m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
+--- !u!114 &4167915178638071617
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 7956182162252432618}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 2db441f589c3407bb6fb5f02ff8ab541, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  m_inverted: 0
+  m_shapes:
+  - Object:
+      referencePath: shape deletion test mesh
+      targetObject: {fileID: 0}
+    ShapeName: bottom
+    ChangeType: 1
+    Value: 0
+--- !u!114 &3280847981733507148
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 7956182162252432618}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 3b29d45007c5493d926d2cd45a489529, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  Control:
+    name: 
+    icon: {fileID: 0}
+    type: 102
+    parameter:
+      name: 
+    value: 1
+    style: 0
+    subMenu: {fileID: 0}
+    subParameters: []
+    labels: []
+  MenuSource: 1
+  menuSource_otherObjectChildren: {fileID: 0}
+  isSynced: 1
+  isSaved: 1
+  isDefault: 0
+  automaticValue: 1
+--- !u!1 &8389945206789797712
+GameObject:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  serializedVersion: 6
+  m_Component:
+  - component: {fileID: 6867583134219554799}
+  - component: {fileID: 8099891503683627458}
+  m_Layer: 0
+  m_Name: NullSet
+  m_TagString: Untagged
+  m_Icon: {fileID: 0}
+  m_NavMeshLayer: 0
+  m_StaticEditorFlags: 0
+  m_IsActive: 0
+--- !u!4 &6867583134219554799
+Transform:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 8389945206789797712}
+  serializedVersion: 2
+  m_LocalRotation: {x: 0, y: 0, z: 0, w: 1}
+  m_LocalPosition: {x: 0, y: 0, z: 0}
+  m_LocalScale: {x: 1, y: 1, z: 1}
+  m_ConstrainProportionsScale: 1
+  m_Children: []
+  m_Father: {fileID: 3251791125987375227}
+  m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
+--- !u!114 &8099891503683627458
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 8389945206789797712}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 2db441f589c3407bb6fb5f02ff8ab541, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  m_inverted: 0
+  m_shapes:
+  - Object:
+      referencePath: shape deletion test mesh
+      targetObject: {fileID: 0}
+    ShapeName: bottom
+    ChangeType: 1
+    Value: 0
+--- !u!1001 &9210451080691405271
+PrefabInstance:
+  m_ObjectHideFlags: 0
+  serializedVersion: 2
+  m_Modification:
+    serializedVersion: 3
+    m_TransformParent: {fileID: 3251791125987375227}
+    m_Modifications:
+    - target: {fileID: -8679921383154817045, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_LocalPosition.x
+      value: -0
+      objectReference: {fileID: 0}
+    - target: {fileID: -8679921383154817045, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_LocalPosition.y
+      value: 0
+      objectReference: {fileID: 0}
+    - target: {fileID: -8679921383154817045, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_LocalPosition.z
+      value: 0
+      objectReference: {fileID: 0}
+    - target: {fileID: -8679921383154817045, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_LocalRotation.w
+      value: 0.7071067
+      objectReference: {fileID: 0}
+    - target: {fileID: -8679921383154817045, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_LocalRotation.x
+      value: -0.7071068
+      objectReference: {fileID: 0}
+    - target: {fileID: -8679921383154817045, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_LocalRotation.y
+      value: 0
+      objectReference: {fileID: 0}
+    - target: {fileID: -8679921383154817045, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_LocalRotation.z
+      value: -0
+      objectReference: {fileID: 0}
+    - target: {fileID: -8679921383154817045, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_LocalEulerAnglesHint.x
+      value: 0
+      objectReference: {fileID: 0}
+    - target: {fileID: -8679921383154817045, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_LocalEulerAnglesHint.y
+      value: 0
+      objectReference: {fileID: 0}
+    - target: {fileID: -8679921383154817045, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_LocalEulerAnglesHint.z
+      value: 0
+      objectReference: {fileID: 0}
+    - target: {fileID: -3887185075125053422, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_DirtyAABB
+      value: 0
+      objectReference: {fileID: 0}
+    - target: {fileID: -3887185075125053422, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_AABB.m_Extent.x
+      value: 1
+      objectReference: {fileID: 0}
+    - target: {fileID: -3887185075125053422, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_AABB.m_Extent.y
+      value: 1
+      objectReference: {fileID: 0}
+    - target: {fileID: -3887185075125053422, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_AABB.m_Extent.z
+      value: 2
+      objectReference: {fileID: 0}
+    - target: {fileID: -3887185075125053422, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_BlendShapeWeights.Array.data[0]
+      value: 0
+      objectReference: {fileID: 0}
+    - target: {fileID: 919132149155446097, guid: fe5b76dae94c07345b74d51e9a9a8440,
+        type: 3}
+      propertyPath: m_Name
+      value: shape deletion test mesh
+      objectReference: {fileID: 0}
+    m_RemovedComponents: []
+    m_RemovedGameObjects: []
+    m_AddedGameObjects: []
+    m_AddedComponents: []
+  m_SourcePrefab: {fileID: 100100000, guid: fe5b76dae94c07345b74d51e9a9a8440, type: 3}
+--- !u!4 &8671858138418525756 stripped
+Transform:
+  m_CorrespondingSourceObject: {fileID: -8679921383154817045, guid: fe5b76dae94c07345b74d51e9a9a8440,
+    type: 3}
+  m_PrefabInstance: {fileID: 9210451080691405271}
+  m_PrefabAsset: {fileID: 0}
--- a/UnitTests~/ReactiveComponent/DeletionTest.prefab.meta
+++ b/UnitTests~/ReactiveComponent/DeletionTest.prefab.meta
@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: a82669288fc87d94db320a2494fd76c5
+PrefabImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
--- a/UnitTests~/ReactiveComponent/ShapeDeletionAnalysis.cs
+++ b/UnitTests~/ReactiveComponent/ShapeDeletionAnalysis.cs
@ -0,0 +1,98 @@
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using modular_avatar_tests;
+using nadena.dev.modular_avatar.core;
+using nadena.dev.modular_avatar.core.editor;
+using NUnit.Framework;
+using UnityEngine;
+
+public class ShapeDeletionAnalysis : TestBase
+{
+    [Test]
+    public void BasicShapeDeletionAnalysis()
+    {
+        var root = CreatePrefab("DeletionTest.prefab");
+
+        var mesh = AssertPreviewDeletion(root);
+
+        AssertBuildDeletion(mesh, root);
+    }
+
+    [Test]
+    public void WhenShapeDeletionIsConditionedOnSubsequentChanger_DoesNotDelete()
+    {
+        var root = CreatePrefab("DeletionTest.prefab");
+        root.transform.Find("MenuSet").gameObject.SetActive(true);
+
+        AssertPreviewDeletion(root);
+        AssertNoMeshDeletion(root);
+        
+        var mesh = root.GetComponentInChildren<SkinnedMeshRenderer>();
+        Assert.AreEqual(100, mesh.GetBlendShapeWeight(mesh.sharedMesh.GetBlendShapeIndex("bottom")));
+    }
+
+
+    [Test]
+    public void WhenShapeDeletionIsConditionedOnItself_DoesNotDelete()
+    {
+        var root = CreatePrefab("DeletionTest.prefab");
+        root.transform.Find("Delete").gameObject.AddComponent<ModularAvatarMenuItem>().InitSettings();
+        
+        AssertNoPreviewDeletion(root);
+        AssertNoMeshDeletion(root);
+        
+        var mesh = root.GetComponentInChildren<SkinnedMeshRenderer>();
+        // deletion action is initially off, so we use the shape changer above it, which is set to 50.
+        Assert.AreEqual(50f, mesh.GetBlendShapeWeight(mesh.sharedMesh.GetBlendShapeIndex("bottom")));
+    }
+    
+    private static void AssertBuildDeletion(SkinnedMeshRenderer mesh, GameObject root)
+    {
+        var originalSharedMesh = mesh.sharedMesh;
+        AvatarProcessor.ProcessAvatar(root);
+        Assert.AreNotEqual(originalSharedMesh, mesh.sharedMesh);
+
+        Assert.IsTrue(mesh.sharedMesh.vertices.All(v => v.z >= 0));
+    }
+
+    private static SkinnedMeshRenderer AssertPreviewDeletion(GameObject root)
+    {
+        var mesh = root.GetComponentInChildren<SkinnedMeshRenderer>();
+        var analysis = new ReactiveObjectAnalyzer().Analyze(root);
+        var deletedShape = analysis.Shapes.GetValueOrDefault(new TargetProp()
+        {
+            TargetObject = mesh,
+            PropertyName = "deletedShape.bottom"
+        });
+        Assert.IsNotNull(deletedShape);
+        var activeGroup = deletedShape.actionGroups.LastOrDefault(ag => ag.InitiallyActive);
+        Assert.AreEqual(1.0f, activeGroup?.Value);
+        return mesh;
+    }
+    
+    private static void AssertNoPreviewDeletion(GameObject root)
+    {
+        var mesh = root.GetComponentInChildren<SkinnedMeshRenderer>();
+        var analysis = new ReactiveObjectAnalyzer().Analyze(root);
+        var deletedShape = analysis.Shapes.GetValueOrDefault(new TargetProp()
+        {
+            TargetObject = mesh,
+            PropertyName = "deletedShape.bottom"
+        });
+        if (deletedShape != null)
+        {
+            var activeGroup = deletedShape.actionGroups.LastOrDefault(ag => ag.InitiallyActive);
+            Assert.IsFalse(activeGroup?.Value is float f && f > 0);
+        }
+        
+    }
+
+    private static void AssertNoMeshDeletion(GameObject root)
+    {
+        var mesh = root.GetComponentInChildren<SkinnedMeshRenderer>();
+        var originalSharedMesh = mesh.sharedMesh;
+        AvatarProcessor.ProcessAvatar(root);
+        Assert.AreEqual(originalSharedMesh, mesh.sharedMesh);
+    }
+}
--- a/UnitTests~/ReactiveComponent/ShapeDeletionAnalysis.cs.meta
+++ b/UnitTests~/ReactiveComponent/ShapeDeletionAnalysis.cs.meta
@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 18eb55e1b66a00243a91142456dfd5f5
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
--- a/UnitTests~/ReactiveComponent/shape
+++ b/UnitTests~/ReactiveComponent/shape
--- a/UnitTests~/ReactiveComponent/shape
+++ b/UnitTests~/ReactiveComponent/shape
@ -0,0 +1,109 @@
+fileFormatVersion: 2
+guid: fe5b76dae94c07345b74d51e9a9a8440
+ModelImporter:
+  serializedVersion: 22200
+  internalIDToNameTable: []
+  externalObjects: {}
+  materials:
+    materialImportMode: 2
+    materialName: 0
+    materialSearch: 1
+    materialLocation: 1
+  animations:
+    legacyGenerateAnimations: 4
+    bakeSimulation: 0
+    resampleCurves: 1
+    optimizeGameObjects: 0
+    removeConstantScaleCurves: 0
+    motionNodeName: 
+    rigImportErrors: 
+    rigImportWarnings: 
+    animationImportErrors: 
+    animationImportWarnings: 
+    animationRetargetingWarnings: 
+    animationDoRetargetingWarnings: 0
+    importAnimatedCustomProperties: 0
+    importConstraints: 0
+    animationCompression: 1
+    animationRotationError: 0.5
+    animationPositionError: 0.5
+    animationScaleError: 0.5
+    animationWrapMode: 0
+    extraExposedTransformPaths: []
+    extraUserProperties: []
+    clipAnimations: []
+    isReadable: 0
+  meshes:
+    lODScreenPercentages: []
+    globalScale: 1
+    meshCompression: 0
+    addColliders: 0
+    useSRGBMaterialColor: 1
+    sortHierarchyByName: 1
+    importPhysicalCameras: 1
+    importVisibility: 1
+    importBlendShapes: 1
+    importCameras: 1
+    importLights: 1
+    nodeNameCollisionStrategy: 1
+    fileIdsGeneration: 2
+    swapUVChannels: 0
+    generateSecondaryUV: 0
+    useFileUnits: 1
+    keepQuads: 0
+    weldVertices: 1
+    bakeAxisConversion: 0
+    preserveHierarchy: 0
+    skinWeightsMode: 0
+    maxBonesPerVertex: 4
+    minBoneWeight: 0.001
+    optimizeBones: 1
+    meshOptimizationFlags: -1
+    indexFormat: 0
+    secondaryUVAngleDistortion: 8
+    secondaryUVAreaDistortion: 15.000001
+    secondaryUVHardAngle: 88
+    secondaryUVMarginMethod: 1
+    secondaryUVMinLightmapResolution: 40
+    secondaryUVMinObjectScale: 1
+    secondaryUVPackMargin: 4
+    useFileScale: 1
+    strictVertexDataChecks: 0
+  tangentSpace:
+    normalSmoothAngle: 60
+    normalImportMode: 0
+    tangentImportMode: 3
+    normalCalculationMode: 4
+    legacyComputeAllNormalsFromSmoothingGroupsWhenMeshHasBlendShapes: 0
+    blendShapeNormalImportMode: 1
+    normalSmoothingSource: 0
+  referencedClips: []
+  importAnimation: 1
+  humanDescription:
+    serializedVersion: 3
+    human: []
+    skeleton: []
+    armTwist: 0.5
+    foreArmTwist: 0.5
+    upperLegTwist: 0.5
+    legTwist: 0.5
+    armStretch: 0.05
+    legStretch: 0.05
+    feetSpacing: 0
+    globalScale: 1
+    rootMotionBoneName: 
+    hasTranslationDoF: 0
+    hasExtraRoot: 0
+    skeletonHasParents: 1
+  lastHumanDescriptionAvatarSource: {instanceID: 0}
+  autoGenerateAvatarMappingIfUnspecified: 1
+  animationType: 2
+  humanoidOversampling: 1
+  avatarSetup: 0
+  addHumanoidExtraRootOnlyWhenUsingAvatar: 1
+  importBlendShapeDeformPercent: 1
+  remapMaterialsIfMaterialImportModeIsNone: 0
+  additionalBone: 0
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: