diff --git a/Editor/UI/GeneratedAssetsEditor.cs b/Editor/UI/GeneratedAssetsEditor.cs
new file mode 100644
index 00000000..66e23156
--- /dev/null
+++ b/Editor/UI/GeneratedAssetsEditor.cs
@@ -0,0 +1,287 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using nadena.dev.ndmf.runtime;
+using UnityEditor;
+using UnityEngine;
+using VRC.SDK3.Avatars.ScriptableObjects;
+using Object = UnityEngine.Object;
+
+namespace nadena.dev.ndmf.ui
+{
+    [CustomEditor(typeof(GeneratedAssets))]
+    class MAAssetBundleEditor : Editor
+    {
+        public override void OnInspectorGUI()
+        {
+            if (GUILayout.Button("Unpack"))
+            {
+                foreach (var target in targets)
+                {
+                    GeneratedAssets bundle = (GeneratedAssets) target;
+                    bundle.Extract();
+                }
+            }
+        }
+    }
+
+    public static class GeneratedAssetBundleExtension
+    {
+        /// <summary>
+        /// Extracts a generated assets bundle into separate asset files
+        /// </summary>
+        /// <param name="bundle"></param>
+        public static void Extract(this GeneratedAssets bundle)
+        {
+            new GeneratedAssetBundleExtractor(bundle).Extract();
+        }
+    }
+    
+    internal class GeneratedAssetBundleExtractor
+    {
+        private static readonly ISet<Type> RootAssets = new HashSet<Type>()
+        {
+            typeof(Mesh),
+            typeof(AnimationClip),
+            typeof(RuntimeAnimatorController),
+            typeof(VRCExpressionParameters),
+            typeof(VRCExpressionsMenu),
+        };
+
+        private Dictionary<UnityEngine.Object, AssetInfo> _assets;
+        private GeneratedAssets Bundle;
+        private HashSet<Object> _unassigned;
+        
+        internal GeneratedAssetBundleExtractor(GeneratedAssets bundle)
+        {
+            _assets = GetContainedAssets(bundle);
+            this.Bundle = bundle;
+        }
+
+        class AssetInfo
+        {
+            public readonly UnityEngine.Object Asset;
+            public readonly HashSet<AssetInfo> IncomingReferences = new HashSet<AssetInfo>();
+            public readonly HashSet<AssetInfo> OutgoingReferences = new HashSet<AssetInfo>();
+
+            public AssetInfo Root;
+
+            public AssetInfo(UnityEngine.Object obj)
+            {
+                this.Asset = obj;
+            }
+
+            public void PopulateReferences(Dictionary<UnityEngine.Object, AssetInfo> assets)
+            {
+                if (Asset is Mesh || Asset is AnimationClip || Asset is VRCExpressionsMenu ||
+                    Asset is VRCExpressionsMenu)
+                {
+                    return; // No child objects
+                }
+
+                var so = new SerializedObject(Asset);
+                var prop = so.GetIterator();
+
+                // TODO extract to common code
+                bool enterChildren = true;
+                while (prop.Next(enterChildren))
+                {
+                    enterChildren = true;
+                    if (prop.propertyType == SerializedPropertyType.ObjectReference)
+                    {
+                        var value = prop.objectReferenceValue;
+                        if (value != null && assets.TryGetValue(value, out var target))
+                        {
+                            OutgoingReferences.Add(target);
+                            target.IncomingReferences.Add(this);
+                        }
+                    }
+                    else if (prop.propertyType == SerializedPropertyType.String)
+                    {
+                        enterChildren = false;
+                    }
+                }
+            }
+
+            public void ForceAssignRoot()
+            {
+                // First, see if we're reachable only from one root.
+                HashSet<AssetInfo> visited = new HashSet<AssetInfo>();
+                HashSet<AssetInfo> roots = new HashSet<AssetInfo>();
+                Queue<AssetInfo> queue = new Queue<AssetInfo>();
+                visited.Add(this);
+                queue.Enqueue(this);
+
+                while (queue.Count > 0 && roots.Count < 2)
+                {
+                    var next = queue.Dequeue();
+                    if (next.Root != null)
+                    {
+                        roots.Add(next.Root);
+                    }
+
+                    foreach (var outgoingReference in next.IncomingReferences)
+                    {
+                        if (visited.Add(outgoingReference))
+                        {
+                            queue.Enqueue(outgoingReference);
+                        }
+                    }
+                }
+
+                if (roots.Count == 1)
+                {
+                    this.Root = roots.First();
+                }
+                else
+                {
+                    this.Root = this;
+                }
+            }
+        }
+
+        public static void Unpack(GeneratedAssets bundle)
+        {
+            try
+            {
+                AssetDatabase.StartAssetEditing();
+                new GeneratedAssetBundleExtractor(bundle).Extract();
+            }
+            finally
+            {
+                AssetDatabase.StopAssetEditing();
+            }
+        }
+
+
+        private bool TryAssignRoot(AssetInfo info)
+        {
+            if (info.Root != null)
+            {
+                return true;
+            }
+
+            if (RootAssets.Any(t => t.IsInstanceOfType(info.Asset)) || info.IncomingReferences.Count == 0)
+            {
+                info.Root = info;
+                return true;
+            }
+
+            var firstRoot = info.IncomingReferences.First().Root;
+            if (firstRoot != null && !_unassigned.Contains(firstRoot.Asset)
+                                  && info.IncomingReferences.All(t => t.Root == firstRoot))
+            {
+                info.Root = firstRoot;
+                return true;
+            }
+
+            return false;
+        }
+
+        internal void Extract()
+        {
+            string path = AssetDatabase.GetAssetPath(Bundle);
+            var directory = System.IO.Path.GetDirectoryName(path);
+            _unassigned = new HashSet<UnityEngine.Object>(_assets.Keys);
+
+            foreach (var info in _assets.Values)
+            {
+                info.PopulateReferences(_assets);
+            }
+
+            var queue = new Queue<UnityEngine.Object>();
+            while (_unassigned.Count > 0)
+            {
+                // Bootstrap
+                if (queue.Count == 0)
+                {
+                    _unassigned.Where(o => TryAssignRoot(_assets[o])).ToList().ForEach(o => { queue.Enqueue(o); });
+
+                    if (queue.Count == 0)
+                    {
+                        _assets[_unassigned.First()].ForceAssignRoot();
+                        queue.Enqueue(_unassigned.First());
+                    }
+                }
+
+                while (queue.Count > 0)
+                {
+                    var next = queue.Dequeue();
+                    ProcessSingleAsset(directory, next);
+                    _unassigned.Remove(next);
+
+                    foreach (var outgoingReference in _assets[next].OutgoingReferences)
+                    {
+                        if (_unassigned.Contains(outgoingReference.Asset) && TryAssignRoot(outgoingReference))
+                        {
+                            queue.Enqueue(outgoingReference.Asset);
+                        }
+                    }
+                }
+            }
+
+            AssetDatabase.DeleteAsset(path);
+        }
+
+        private string AssignAssetFilename(string directory, Object next)
+        {
+            string assetName = next.name;
+            if (string.IsNullOrEmpty(assetName))
+            {
+                next.name = next.GetType().Name + " " + GUID.Generate().ToString();
+                assetName = next.name;
+            }
+
+            string assetFile;
+            for (int extension = 0;; extension++)
+            {
+                assetFile = assetName + (extension == 0 ? "" : $" ({extension})") + ".asset";
+                assetFile = System.IO.Path.Combine(directory, assetFile);
+                if (!System.IO.File.Exists(assetFile))
+                {
+                    break;
+                }
+            }
+
+            return assetFile;
+        }
+
+        private void ProcessSingleAsset(string directory, Object next)
+        {
+            AssetDatabase.RemoveObjectFromAsset(next);
+
+            var info = _assets[next];
+            if (info.Root != info)
+            {
+                if (!AssetDatabase.IsMainAsset(info.Root.Asset))
+                {
+                    throw new Exception(
+                        $"Desired root {info.Root.Asset.name} for asset {next.name} is not a root asset");
+                }
+
+                AssetDatabase.AddObjectToAsset(next, info.Root.Asset);
+            }
+            else
+            {
+                AssetDatabase.CreateAsset(next, AssignAssetFilename(directory, next));
+            }
+        }
+
+        private static Dictionary<Object, AssetInfo> GetContainedAssets(GeneratedAssets bundle)
+        {
+            string path = AssetDatabase.GetAssetPath(bundle);
+            var rawAssets = AssetDatabase.LoadAllAssetsAtPath(path);
+            Dictionary<Object, AssetInfo> infos = new Dictionary<Object, AssetInfo>(rawAssets.Length);
+            foreach (var asset in rawAssets)
+            {
+                if (!(asset is GeneratedAssets))
+                {
+                    infos.Add(asset, new AssetInfo(asset));
+                }
+            }
+
+
+            return infos;
+        }
+    }
+}
\ No newline at end of file
diff --git a/Editor/UI/GeneratedAssetsEditor.cs.meta b/Editor/UI/GeneratedAssetsEditor.cs.meta
new file mode 100644
index 00000000..443c23d5
--- /dev/null
+++ b/Editor/UI/GeneratedAssetsEditor.cs.meta
@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 3744b23a07ec450890ea6c2f01de524d
+timeCreated: 1695205801
\ No newline at end of file