Version: 2021.2
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public static void RegisterCreatedObjectUndo(Object objectToUndo, string name);


objectToUndo The newly created object. This object is destroyed when the undo operation is performed. When the value is a GameObject, Unity registers the GameObject and its child GameObjects, but not sibling or parent GameObjects.
name The name of the action to undo. Use this string to provide a short description of the action to be undone. For Undo or Redo items in the Edit menu, Unity adds "Undo" or "Redo" to the string that you provide. For example, if you provide the string "Create GameObject", the Unity Editor displays the menu item Edit > Undo Create GameObject.


Registers an undo operation to undo the creation of an object.

This method registers the creation of an object to the undo stack so that users can undo a create object action. Use this method each time you define an action that creates an object, for example, inside a custom Editor or menu item. Unity updates the undo action in the Edit menu with the name of the undo operation. When the user performs the undo action, Unity destroys the object.

Note: The undo process destroys objects in the same way as Object.Destroy, but with no delay.

When you create and modify an object at the same time, use the following workflow to ensure that Undo.RegisterCreatedObjectUndo saves all updates to the object:

  1. Create the object.
  2. Register the object as created with Undo.RegisterCreatedObjectUndo.
  3. Register the object with Undo.RegisterCompleteObjectUndo so that Unity records changes to the object.
  4. Update the object.

If you do not follow this workflow, Undo.RegisterCreatedObjectUndo might not save any updates to the object other than object creation.

When you register a new object with Undo.RegisterCreatedObjectUndo, Unity registers any changes to objects that are currently recorded by Undo.RecordObject and then stops recording. This means that after you register a new object, Unity does not record any subsequent changes to any other objects that Undo.RecordObject was already recording.

When Unity is already recording changes to existing objects with Undo.RecordObject and you want to register newly created objects, it is best practice to follow this workflow:

  1. Complete any changes you want to make to objects that Undo.RecordObject is recording. Unity calls Undo.FlushUndoRecordObjects automatically.
  2. Register newly created objects with Undo.RegisterCreatedObjectUndo.

If you do not follow this workflow, Unity might not store the state of the recorded objects on the undo stack correctly.

The following example shows how to create and modify a GameObject with a child as an operation that can be undone in a single undo step.

using UnityEditor;
using UnityEngine;

class CreateGameObjectMenu { [MenuItem("Example/Create GameObject")] static void CreateGameObject() { // Create new undo group Undo.IncrementCurrentGroup();

// Create GameObject hierarchy GameObject go = new GameObject("my GameObject"); Undo.RegisterCreatedObjectUndo(go, "Create my GameObject"); GameObject child = new GameObject(); Undo.RegisterCreatedObjectUndo(child, "Create child"); Undo.SetTransformParent(child.transform, go.transform, "Modify parent");

// Move GameObject hierarchy Undo.RegisterFullObjectHierarchyUndo(go, "Update my GameObject position"); go.transform.position = new Vector3(5, 5, 5);

// Name undo group Undo.SetCurrentGroupName("Create and Reposition GameObject with Child"); } }