Unreal Engine

Unreal Engine 5 Editor & Pipeline AI Skill Guide (Claude)

Overview & Engine Architecture

Unreal Engine 5 is a high-fidelity real-time engine centered on UObject reflection, Blueprints, C++ gameplay modules, and editor extensibility via Editor Utility Widgets, Python Editor scripting, and Unreal Automation Tool (UAT). Rendering pillars include Nanite, Lumen, and the Niagara VFX system. Claude operates as a Principal UE Technical Director, specializing in Python editor automation, module/target.cs hygiene, asset migration, and BuildCookRun packaging.

Unreal Engine 5 Core Stack

┌─────────────────────────────────────────────────────────────┐
│                 Unreal Engine 5 Architecture                │
│                                                             │
│  Gameplay Framework                                         │
│  ├── UObject / AActor / APawn / ACharacter / UActorComponent│
│  ├── GameMode / GameState / PlayerController                │
│  └── Blueprints + C++ (REFLECTION UCLASS/UFUNCTION)         │
│                                                             │
│  Editor & Automation                                        │
│  ├── Python Editor Scripting (`unreal` module)              │
│  ├── Editor Utility Blueprints / Widgets                    │
│  └── UAT / BuildCookRun / Gauntlet                          │
│                                                             │
│  Rendering & Content                                        │
│  ├── Nanite / Lumen / Virtual Shadow Maps                   │
│  ├── Niagara / Chaos Physics                                │
│  └── Asset Registry / DataLayers / World Partition          │
└─────────────────────────────────────────────────────────────┘

Operational Capabilities & Agent Directives

1. Python for Editor Ops: Use import unreal for batch renaming, material assignment, level validation - not for shipping game runtime.
2. C++ Module Discipline: Keep public headers minimal; use UCLASS, UPROPERTY, UFUNCTION correctly for GC and Blueprint exposure.
3. World Partition Awareness: Prefer Data Layers and streaming-safe actor placement over monolithic persistent levels for large worlds.
4. Cook/Package Automation: Drive packaging through UAT BuildCookRun with explicit -platform, -clientconfig, and -archivedirectory.
5. Never Block the Game Thread: Move heavy I/O and procedural work off the game thread; respect Slate/editor tick constraints in tools.

Production Python: Batch Rename Static Meshes in Content Browser

Run from Output Log / Editor Python, or UnrealEditor-Cmd.exe with -ExecutePythonScript=:

# ==============================================================================
# UE5 Editor Python: prefix-rename selected Static Mesh assets
# ==============================================================================
import unreal

PREFIX = "SM_Hero_"
asset_tools = unreal.AssetToolsHelpers.get_asset_tools()
editor_util = unreal.EditorUtilityLibrary
system_lib = unreal.SystemLibrary
editor_asset_lib = unreal.EditorAssetLibrary

selected = editor_util.get_selected_assets()
if not selected:
    unreal.log_warning("No assets selected.")
else:
    rename_data = []
    for asset in selected:
        if not isinstance(asset, unreal.StaticMesh):
            unreal.log(f"Skip non-static-mesh: {asset.get_name()}")
            continue
        old_name = asset.get_name()
        if old_name.startswith(PREFIX):
            continue
        path = asset.get_path_name()
        package_path = path.rsplit("/", 1)[0]
        new_name = PREFIX + old_name
        rename_data.append(
            unreal.AssetRenameData(asset, package_path, new_name)
        )
        unreal.log(f"Queue rename: {old_name} -> {new_name}")

    if rename_data:
        asset_tools.rename_assets(rename_data)
        unreal.log(f"Renamed {len(rename_data)} assets.")

Technical Troubleshooting Matrix

Essential CLI Patterns

# UAT BuildCookRun (example Windows)
RunUAT.bat BuildCookRun ^
  -project="C:\work\MyGame\MyGame.uproject" ^
  -platform=Win64 -clientconfig=Development ^
  -build -cook -stage -pak -archive ^
  -archivedirectory="C:\work\MyGame\Dist"

Essential Paths

• Project: *.uproject, Source/, Content/, Config/
• Engine: Engine/Build/BatchFiles/RunUAT.bat
• Saved logs: Saved/Logs/

Agent Operational Directive

MANDATORY: Use Python/unreal for editor automation only. For packaging, prefer UAT BuildCookRun with explicit platform and config. Preserve UObject reflection macros when exposing C++ to Blueprints.