diff --git a/Editor/API/AnimatorServices/ObjectPathRemapper.cs b/Editor/API/AnimatorServices/ObjectPathRemapper.cs
new file mode 100644
index 0000000..5546bdf
--- /dev/null
+++ b/Editor/API/AnimatorServices/ObjectPathRemapper.cs
@@ -0,0 +1,138 @@
+using System.Collections.Generic;
+using nadena.dev.ndmf.runtime;
+using UnityEngine;
+
+namespace nadena.dev.ndmf.animator
+{
+    /// <summary>
+    ///     The ObjectPathRemapper is used to track GameObject movement in the hierarchy, and to update animation paths
+    ///     accordingly.
+    ///     While the ObjectPathRemapper is active, there are a few important rules around hierarchy and animation
+    ///     maniuplation that must be observed.
+    ///     1. The ObjectPathRemapper takes a snapshot of the object paths that were present at time of activation;
+    ///     as such, any new animations added while it is active must use those paths, not those of the current
+    ///     hierarchy. To help with this, you can use the `GetVirtualPathForObject` method to get the path that
+    ///     should be used for newly generated animations.
+    ///     2. Objects can be moved freely within the hierarchy; however, if you want to _remove_ an object, you must call
+    ///     `ReplaceObject` on it first.
+    ///     3. Objects can be freely added; if you want to use those objects in animations, use `GetVirtualPathForObject`
+    ///     to get the path that should be used. This will automatically register that object, if necessary. If you'd
+    ///     like to use animation clips with pre-existing paths on, for example, a newly instantiated prefab hierarchy,
+    ///     use `RecordObjectTree` to ensure that those objects have their current paths recorded first. This ensures
+    ///     that if those objects are moved in later stages, the paths will be updated appropriately.
+    ///     Note that it's possible that these paths may collide with paths that _previously_ existed, so it's still
+    ///     recommended to use `GetVirtualPathForObject` to ensure that the path is unique.
+    /// </summary>
+    public class ObjectPathRemapper
+    {
+        private readonly Transform _root;
+        private readonly Dictionary<Transform, List<string>> _objectToOriginalPaths = new();
+        private readonly Dictionary<string, Transform> _pathToObject = new();
+
+        private bool _cacheValid;
+        private readonly Dictionary<string, string> _originalToMappedPath = new();
+
+        internal ObjectPathRemapper(Transform root)
+        {
+            _root = root;
+            RecordObjectTree(root);
+        }
+
+        public void ApplyChanges(AnimationIndex index)
+        {
+            UpdateCache();
+
+            index.RewritePaths(_originalToMappedPath);
+        }
+
+        private void UpdateCache()
+        {
+            if (_cacheValid) return;
+
+            _originalToMappedPath.Clear();
+
+            foreach (var kvp in _objectToOriginalPaths)
+            {
+                foreach (var path in kvp.Value)
+                {
+                    _originalToMappedPath[path] = GetVirtualPathForObject(kvp.Key);
+                }
+            }
+        }
+
+        public void RecordObjectTree(Transform subtree)
+        {
+            GetVirtualPathForObject(subtree);
+
+            foreach (Transform child in subtree)
+            {
+                RecordObjectTree(child);
+            }
+        }
+
+        public GameObject GetObjectForPath(string path)
+        {
+            var xform = _pathToObject.GetValueOrDefault(path);
+            return xform ? xform.gameObject : null;
+        }
+
+        public string GetVirtualPathForObject(GameObject obj)
+        {
+            return GetVirtualPathForObject(obj.transform);
+        }
+
+        public string GetVirtualPathForObject(Transform t)
+        {
+            if (_objectToOriginalPaths.TryGetValue(t, out var paths))
+            {
+                return paths[0];
+            }
+
+            var path = RuntimeUtil.RelativePath(_root, t);
+            if (path == null) return null;
+
+            if (_pathToObject.ContainsKey(path))
+            {
+                path += "###PENDING_" + t.GetInstanceID();
+            }
+
+            _objectToOriginalPaths[t] = new List<string> { path };
+            _pathToObject[path] = t;
+            _cacheValid = false;
+
+            return path;
+        }
+
+        public void ReplaceObject(GameObject old, GameObject newObject)
+        {
+            ReplaceObject(old.transform, newObject.transform);
+        }
+
+        public void ReplaceObject(Transform old, Transform newObject)
+        {
+            if (!_objectToOriginalPaths.TryGetValue(old, out var paths)) return;
+
+            if (_objectToOriginalPaths.ContainsKey(newObject))
+            {
+                _objectToOriginalPaths[newObject].AddRange(paths);
+            }
+            else
+            {
+                _objectToOriginalPaths[newObject] = paths;
+            }
+
+            _objectToOriginalPaths.Remove(old);
+            foreach (var path in paths)
+            {
+                _pathToObject[path] = newObject;
+            }
+        }
+
+        public string MapPath(string originalPath)
+        {
+            UpdateCache();
+
+            return _originalToMappedPath.GetValueOrDefault(originalPath, originalPath);
+        }
+    }
+}
\ No newline at end of file
diff --git a/Editor/API/AnimatorServices/ObjectPathRemapper.cs.meta b/Editor/API/AnimatorServices/ObjectPathRemapper.cs.meta
new file mode 100644
index 0000000..24ad97b
--- /dev/null
+++ b/Editor/API/AnimatorServices/ObjectPathRemapper.cs.meta
@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 555cbff33c8d467ea13832f7b650b15a
+timeCreated: 1731273374
\ No newline at end of file
diff --git a/Runtime/RuntimeUtil.cs b/Runtime/RuntimeUtil.cs
index 86ffbc8..de3d24a 100644
--- a/Runtime/RuntimeUtil.cs
+++ b/Runtime/RuntimeUtil.cs
@@ -1,9 +1,9 @@
 using System;
 using System.Collections.Generic;
 using JetBrains.Annotations;
+using UnityEditor;
 using UnityEngine;
 using UnityEngine.SceneManagement;
-
 #if NDMF_VRCSDK3_AVATARS
 using VRC.SDK3.Avatars.Components;
 #endif
@@ -43,7 +43,7 @@ internal static T GetOrAddComponent<T>(this Component obj) where T : Component
         /// Returns whether the editor is in play mode.
         /// </summary>
 #if UNITY_EDITOR
-        public static bool IsPlaying => UnityEditor.EditorApplication.isPlayingOrWillChangePlaymode;
+        public static bool IsPlaying => EditorApplication.isPlayingOrWillChangePlaymode;
 #else
         public static bool IsPlaying => true;
 #endif
@@ -56,22 +56,34 @@ internal static T GetOrAddComponent<T>(this Component obj) where T : Component
         /// <returns></returns>
         [CanBeNull]
         public static string RelativePath(GameObject root, GameObject child)
+        {
+            return RelativePath(root.transform, child.transform);
+        }
+
+        /// <summary>
+        ///     Returns the relative path from root to child, or null is child is not a descendant of root.
+        /// </summary>
+        /// <param name="root"></param>
+        /// <param name="child"></param>
+        /// <returns></returns>
+        [CanBeNull]
+        public static string RelativePath(Transform root, Transform child)
         {
             if (root == child) return "";
 
-            List<string> pathSegments = new List<string>();
+            var pathSegments = new List<string>();
             while (child != root && child != null)
             {
-                pathSegments.Add(child.name);
-                child = child.transform.parent?.gameObject;
+                pathSegments.Add(child.gameObject.name);
+                child = child.parent;
             }
 
             if (child == null && root != null) return null;
 
             pathSegments.Reverse();
-            return String.Join("/", pathSegments);
+            return string.Join("/", pathSegments);
         }
-
+        
         /// <summary>
         /// Returns the path of a game object relative to the avatar root, or null if the avatar root could not be
         /// located.