Automate and extend the Unreal Editor using Python (the `unreal` module, startup scripts, commandlets), Editor Utility Widgets/Blueprints (Blutility — UEditorUtilityWidget, UEditorUtilityObject, UEditorUtilityWidgetBlueprint, UAssetActionUtility), the editor scripting subsystems (UEditorActorSubsystem, UEditorAssetSubsystem, ULevelEditorSubsystem, UAssetEditorSubsystem, UEditorUtilitySubsystem), and how C++ UFUNCTION specifiers (BlueprintCallable, CallInEditor, ScriptMethod, ScriptName) control which APIs surface in Python and Blueprints. Use when batch-processing assets, building in-editor tools or dockable UMG panels, running headless Python commandlets in CI, scripting repetitive editor tasks, or exposing custom C++ editor APIs to Python/Blueprints. Editor-only — never used in packaged games.
Instalar com Codex ou Claude Copie este prompt, cole no Codex, Claude ou outro assistente e deixe que ele revise a página da skill e instale para você.
Um comando direto ignora o prompt de revisão. Verifique a origem antes de executá-lo.
Instruções da origem · Visualização somente leitura
name
editor-scripting-and-python
description
Automate and extend the Unreal Editor using Python (the `unreal` module, startup scripts, commandlets), Editor Utility Widgets/Blueprints (Blutility — UEditorUtilityWidget, UEditorUtilityObject, UEditorUtilityWidgetBlueprint, UAssetActionUtility), the editor scripting subsystems (UEditorActorSubsystem, UEditorAssetSubsystem, ULevelEditorSubsystem, UAssetEditorSubsystem, UEditorUtilitySubsystem), and how C++ UFUNCTION specifiers (BlueprintCallable, CallInEditor, ScriptMethod, ScriptName) control which APIs surface in Python and Blueprints. Use when batch-processing assets, building in-editor tools or dockable UMG panels, running headless Python commandlets in CI, scripting repetitive editor tasks, or exposing custom C++ editor APIs to Python/Blueprints. Editor-only — never used in packaged games.
metadata
{"engine-version":"5.8","category":"tooling"}
Editor scripting & Python
Everything in this skill is editor-only: it lives in editor modules or behind
WITH_EDITOR and is stripped from packaged games. The two main paths are: the
Python Script Plugin (unreal module) for quick automation and pipeline scripts, and
Blutility (Editor Utility Widgets/Blueprints) for in-editor UI tools callable by
artists and designers.
When to use this skill
Batch operations on assets — rename, set properties, reimport, generate LODs.
Custom in-editor UMG panels (Editor Utility Widgets) for artists.
Context-menu scripted actions triggered from the Content Browser or Level.
Headless commandlet runs in CI without the full editor UI.
Exposing a C++ function so it appears in Python/Blueprints with the correct name.
Obtaining a reference to an editor subsystem from C++ or Python.
Approach comparison
Approach
When to choose
Python (PythonScriptPlugin)
Pipeline automation, batch asset ops, CI jobs, quick scripts
Editor Utility Widget (Blutility)
Artist-facing tool panels with UMG UI in the editor
Editor Utility Blueprint
No-UI scripted actions on assets or actors
C++ editor module + UEditorSubsystem
Robust reusable tools, Slate/menu extensions
Commandlet
Headless batch processing, -run=pythonscript in CI
Python (unreal module)
Enable the Python Editor Script Plugin (Plugins > Scripting). The plugin bundles
Python 3.11.8; no separate install is needed. The unreal module is generated at startup
from whatever is reflected to Blueprints — any BlueprintCallable function or class
exposed by any enabled plugin is automatically available.
Naming convention: C++ class UEditorAssetSubsystem → Python class
unreal.EditorAssetSubsystem. Function GetAllLevelActors() → get_all_level_actors().
Enum values become UPPER_SNAKE_CASE. The U/A/F/T prefix is dropped.
Reading/setting properties:
import unreal
actor = unreal.EditorActorSubsystem().get_actor_reference("PersistentLevel.MyActor")
# BlueprintReadWrite → direct attribute access
val = actor.some_property
# EditAnywhere → use get/set_editor_property for pre/post-edit notifications
actor.set_editor_property("hidden_in_game", True)
Transactions (undo/redo support):
with unreal.ScopedEditorTransaction("Batch rename"):
for asset in assets:
subsystem.rename_asset(asset.get_path_name(), new_path)
Progress feedback for long jobs:
with unreal.ScopedSlowTask(len(assets), "Processing...") as task:
task.make_dialog(True)
for asset in assets:
if task.should_cancel():
break
task.enter_progress_frame(1, f"Processing {asset.get_name()}")
# ... do work
Startup scripts — add paths under Project Settings → Plugins → Python → Startup
Scripts (stored in UPythonScriptPluginSettings::StartupScripts,
Plugins/Experimental/PythonScriptPlugin/Source/PythonScriptPlugin/Private/PythonScriptPluginSettings.h:67).
Auto-detected init_unreal.py in any Content/Python folder also runs on startup.
Commandlet (headless):UPythonScriptCommandlet runs a script without the full UI:
See references/python-api.md for the C++↔Python mapping,
get_editor_subsystem, type coercion, logging, and subsystem access patterns.
Editor Utility Widgets & Blueprints (Blutility)
Blutility classes live in Editor/Blutility/. The module is Blutility; add it to your
editor module's PrivateDependencyModuleNames.
Key classes
Class
Base
Purpose
UEditorUtilityWidget
UUserWidget
Dockable UMG panel running in the editor
UEditorUtilityWidgetBlueprint
UWidgetBlueprint
Asset that generates UEditorUtilityWidget
UEditorUtilityObject
UObject
Editor-only utility with no UI; runs on demand
UAssetActionUtility
UEditorUtilityObject
Right-click scripted actions in the Content Browser
UEditorUtilityTask
UObject
Background task managed by UEditorUtilitySubsystem
UEditorUtilityWidget (Editor/Blutility/Classes/EditorUtilityWidget.h:27):
inherits UUserWidget; runs entirely in editor. Run() is a BlueprintImplementableEvent
called when the widget is auto-run. Use TabDisplayName to set the panel name.
UEditorUtilityObject (Editor/Blutility/Classes/EditorUtilityObject.h:20):
pure-logic utility, no UI. Set bRunEditorUtilityOnStartup = true to auto-run after
asset discovery.
UAssetActionUtility (Editor/Blutility/Classes/AssetActionUtility.h:60):
any UFUNCTION(BlueprintCallable) on a subclass appears as a right-click option in the
Content Browser. Populate SupportedClasses (class defaults) to filter which asset types
show the action. GetSupportedClass() is deprecated since UE 5.2.
UEditorUtilitySubsystem manages widget tabs and utility tasks
(Editor/Blutility/Public/EditorUtilitySubsystem.h:47):
// Open an Editor Utility Widget tab from C++:
UEditorUtilitySubsystem* EUS = GEditor->GetEditorSubsystem<UEditorUtilitySubsystem>();
EUS->SpawnAndRegisterTab(MyWidgetBlueprint); // line 88// From Python:// eus = unreal.get_editor_subsystem(unreal.EditorUtilitySubsystem)// eus.spawn_and_register_tab(widget_bp)
UFUNCTION(BlueprintCallable) — surfaces to both Blueprints and Python
Any BlueprintCallable function on a UCLASS is reflected to Python automatically. In
Python the class name loses its prefix and the function name becomes snake_case.
Marks a function to appear as a button in the actor Details panel when an instance is
selected in the editor. Works on AActor and UActorComponent subclasses.
Source: Runtime/CoreUObject/Public/UObject/ObjectMacros.h:1047.
UFUNCTION(BlueprintCallable, Category = "Validation", meta = (CallInEditor = "true"))
voidValidateSetup();
meta = (ScriptMethod) — hoist a static function as an instance method in Python
A static BlueprintFunctionLibrary function that takes a struct or object as its first
parameter can be re-surfaced in Python as a method on that type:
UFUNCTION(BlueprintCallable, meta = (ScriptMethod))
static FVector ScaleVector(const FVector& V, float Factor);
// Python: v.scale_vector(2.0) instead of unreal.MyLib.scale_vector(v, 2.0)
Source: Runtime/CoreUObject/Public/UObject/ObjectMacros.h:1723. Related specifiers:
ScriptMethodSelfReturn (:1726), ScriptMethodMutable (:1729).
meta = (ScriptName = "PythonName") — override the Python/scripting name
UEditorAssetLibrary / UEditorLevelLibrary (EditorScriptingUtilities plugin) were
deprecated in UE 5.0. UEditorLevelLibrary functions carry
UE_DEPRECATED(5.0, "... Use the function in Editor Actor Utilities Subsystem").
Prefer UEditorAssetSubsystem and UEditorActorSubsystem in all new code.
UAssetActionUtility::GetSupportedClass() deprecated UE 5.2; use the SupportedClasses
array in class defaults instead.
Python 3.11.8 is the embedded version for UE 5.8 (VFX Reference Platform CY2024).
Set UE_PYTHON_DIR to embed a different CPython build (requires source rebuild).
Gotchas
Editor-only code in a runtime module → packaging failure. Put editor code behind
WITH_EDITOR or in a module with type Editor.
Python does not ship with the game — it is a tooling/editor-only plugin.
Direct attribute set vs set_editor_property — direct set bypasses pre/post-edit
callbacks; set_editor_property triggers them (same as changing in Details panel). Use
set_editor_property for EditAnywhere properties.
Long Python jobs block the editor UI — wrap with unreal.ScopedSlowTask and yield
enter_progress_frame to keep the editor responsive and allow cancellation.
Forgetting to save — call EAS->SaveAsset() or the Python equivalent; unsaved
changes to assets are lost when the editor closes.
Hardcoding asset paths — use the Asset Registry to discover paths dynamically; see
asset-management.
SpawnActorFromClass vs SpawnActor — SpawnActorFromClass on
UEditorActorSubsystem places into the editor world and notifies the editor; use it
instead of UWorld::SpawnActor for editor-placed actors.
