Open editor undo system up, debug dock Delete SceneWorld objects when processing scene deletes Components/GameObjects start disabled when creating, to avoid enable and quickly disable Fix possible NRE when deleting camera Call SceneWorld.DeletePendingObjects when clearing scene Add Scene.Editor (ISceneEditorSession), allows game to talk to the EditorSession (gizmos etc) Also make selection its own undo system - don't need to save the scene on every click Fix undo system's snapshot system not complying with other undo actions