kevinpbuckley/unreal-engine-skills기술 문서

Each skill is a self-contained folder following the Agent Skills specification: a SKILL.md with YAML frontmatter (name, description) plus Markdown instructions, optionally accompanied by references/, scripts/, and assets/.

The consumer is an autonomous agent, not a human clicking through the editor. The agent:

• Writes and edits Unreal C++ (gameplay classes, modules, build files).
• Works with Blueprints, assets, and editor concepts to assemble and configure games.
• Has the Unreal Engine source available on disk to cross-reference exact APIs.

Skills are pure UE domain knowledge: correct classes, real API signatures, the right patterns, the gotchas, and references into the engine source — not click-by-click UI tutorials, and not tool/automation instructions. The agent brings its own tooling (e.g. an MCP bridge to a live editor) and has separate skills for that; these skills tell it what is correct in Unreal, not which tool to operate.

Skills target 5.8 APIs. Where an API moved or changed between 5.x versions, the skill notes it.

unreal-engine-skills/
├── README.md                  # this file — index + conventions
├── docs/
│   └── skill-authoring-guide.md   # house style for writing skills in this repo
├── evals/                     # golden tasks measuring skill effectiveness (see evals/README.md)
│   └── tasks/
├── scripts/
│   └── check-citations.mjs    # verifies every cited Engine/Source path exists on disk
└── skills/
    ├── <category>/            # core, metahuman, ultra-dynamic-sky, ultra-dynamic-weather
    │   ├── category.md        # category description
    │   └── <skill-name>/
    │       ├── SKILL.md       # required: frontmatter + instructions
    │       ├── references/    # optional: deep-dive docs loaded on demand
    │       ├── scripts/       # optional: runnable helpers (e.g. editor Python)
    │       └── assets/        # optional: templates, snippets
    └── ...

Status: ✅ built · 🟡 planned. (Planned skills are tracked as tasks and built in batches.)

• ✅ ue-gameplay-architecture-planning — brainstorm systems, compare trade-offs, map ownership/communication/data, and produce implementation plans
• ✅ ue-navigating-engine-source — locate and cite exact APIs in the on-disk engine source
• ✅ ue-coding-standards — Epic C++ coding standard, naming prefixes, conventions

• ✅ ue-cpp-fundamentals — UObject, UCLASS/USTRUCT/UENUM, UPROPERTY/UFUNCTION, reflection, GC
• ✅ ue-module-and-build-system — modules, *.Build.cs, *.Target.cs, dependencies
• ✅ ue-project-structure — .uproject, Config/Content/Source layout, plugins
• ✅ ue-memory-and-gc — UPROPERTY ownership, TObjectPtr, weak ptrs, smart pointers
• ✅ ue-core-types-and-containers — TArray/TMap/TSet, FString/FName/FText, math types
• ✅ ue-delegates-and-events — single/multicast/dynamic delegates and events
• ✅ ue-logging-and-assertions — UE_LOG, log categories, check/ensure

• ✅ ue-gameplay-framework — GameInstance, GameMode/GameState, PlayerController, Pawn/Character, PlayerState, HUD
• ✅ ue-actors-and-components — AActor lifecycle, components, attachment, spawning
• ✅ ue-character-and-movement — ACharacter, UCharacterMovementComponent
• ✅ ue-enhanced-input — Enhanced Input actions, mapping contexts, bindings
• ✅ ue-subsystems — Engine/GameInstance/World/LocalPlayer subsystems
• ✅ ue-timers-and-async — FTimerManager, async tasks, latent actions
• ✅ ue-gameplay-tags — FGameplayTag, containers, tag-driven logic
• ✅ ue-gameplay-ability-system — GAS abilities, attributes, effects, tasks

• ✅ ue-blueprint-fundamentals — BP classes, graphs, variables, components, the C++↔BP relationship
• ✅ ue-blueprint-cpp-integration — expose C++ to BP (BlueprintCallable, native events, meta)

• ✅ ue-asset-management — AssetRegistry, soft/hard refs, async loading, FObjectFinder
• ✅ ue-importing-content — meshes/textures/audio, Interchange, FBX/glTF
• ✅ ue-meshes-static-and-skeletal — static & skeletal mesh setup
• ✅ ue-materials-and-shaders — material graph, instances, parameters, material C++
• ✅ ue-material-graph-effects — UV motion, vertex animation, dissolve, glow, and interactive parameters
• ✅ ue-master-material-authoring — reusable PBR graphs, instances, switches, and packed texture channels
• ✅ ue-data-driven-design — DataTables, DataAssets, curves, config-driven systems

• ✅ ue-animation-system — skeletal meshes, AnimInstance/AnimBP, state machines, montages, notifies
• ✅ ue-control-rig-and-ik — Control Rig, IK Rig/Retargeter
• ✅ ue-skin-weights — read, repair, transfer, and bind skeletal mesh skin weights (weight painting) via USkinWeightModifier and GeometryScript
• ✅ ue-sequencer-and-cinematics — Sequencer, cameras, cinematics

• ✅ ue-metahuman-creator — MetaHuman Character asset, editor subsystem API (body/face/skin/eyes/makeup), wardrobe palette, cloud auto-rig and texture sources, build/assembly, Python scripting
• ✅ ue-metahuman-animator — capture data ingest (mono video, Live Link Face takes, archives), Identity (Mesh to MetaHuman), Performance processing (depth, mono, audio), AnimSequence/LevelSequence export
• ✅ ue-metahuman-live-link — MetaHuman Video/Audio and Live Link Face sources, subject calibration and smoothing, binding to the assembled MetaHuman face AnimBP, Take Recorder, runtime notes

• ✅ ue-levels-and-world-partition — levels, World Partition, data layers, streaming
• ✅ ue-landscape-and-foliage — landscape, foliage, PCG
• ✅ ue-auto-landscape-materials — painted and generated terrain layers, slope and height masks, projection
• ✅ ue-landscape-rvt-and-grass — runtime virtual textures, ground blending, and material-driven grass
• ✅ ue-lighting-and-lumen — lighting, Lumen GI/reflections
• ✅ ue-nanite-and-rendering — Nanite, rendering features, post process

• ✅ ue-niagara-vfx — Niagara systems, emitters, modules
• ✅ ue-niagara-flamethrower — sustained muzzle flame with layered emitters, runtime controls, and separate damage detection
• ✅ ue-niagara-renderers-and-materials — sprites, mesh particles, ribbons, SubUV, and particle-driven materials
• ✅ ue-niagara-sequenced-effects — timed portals, impacts, beams, projectiles, and attacks
• ✅ ue-niagara-custom-modules — scratch-pad modules, attribute readers, events, and environmental effects
• ✅ ue-niagara-mesh-disintegration — mesh sampling, detached particles, and synchronized dissolve materials
• ✅ ue-audio-and-metasounds — MetaSounds, audio components, attenuation

• ✅ ue-umg-and-slate — UMG widgets, widget C++, Slate, CommonUI

• ✅ ue-networking-and-replication — replication, RPCs, replicated properties, multiplayer
• ✅ ue-physics-and-chaos — collision, physics, Chaos
• ✅ ue-ai-and-navigation — behavior trees, blackboard, EQS, navmesh
• ✅ ue-save-and-load — USaveGame, serialization

• ✅ ue-editor-scripting-and-python — editor utilities, Python, Blutility
• ✅ ue-plugins-and-modules — creating and structuring plugins
• ✅ ue-automation-and-testing — automation specs, functional tests
• ✅ ue-profiling-and-optimization — Unreal Insights, stat commands, memory
• ✅ ue-game-thread-performance — game-thread budgets, FPS impact, optimization levers
• ✅ ue-packaging-and-deployment — cooking, packaging, platforms
• ✅ ue-debugging-techniques — debugger, Gameplay Debugger, Visual Logger

Skills for widely-used marketplace asset packs. These follow the same authoring style as the rest of the repo (frontmatter, system tables, When to use, Gotchas, References & source material) with one deviation from convention: skills cite the pack's documentation + its plugin asset paths (Blueprints/..., Materials/..., Particles/...) instead of Engine/Source/..., and code patterns are Blueprint-flavored pseudocode for packs that have no public C++ API.

• ✅ ue-uds-setup-and-modes — adding UDS to a level, Sky/Color/Project/Feature Mode
• ✅ ue-uds-clouds — Volumetric/Static/2D/Voxel clouds, movement, painter, wisps, light rays
• ✅ ue-uds-time — Time of Day, day/night cycle, runtime functions, event dispatchers
• ✅ ue-uds-sun-moon-stars — sun/moon positioning + appearance, stars, aurora, Space Layer (planets/moons/nebula)
• ✅ ue-uds-lighting-and-shadows — sun/moon directional lights, cloud shadows, sky light modes, exposure, light shafts, Light Day/Night Toggle
• ✅ ue-uds-fog-and-atmosphere — fog density/color, volumetric fog, Global Volumetric Material, dust, sky atmosphere, Simplified Color
• ✅ ue-uds-simulation — real-world sun/moon/stars (lat/long/date/time zone), city presets, Use System Time
• ✅ ue-uds-cinematics-rendering — Sequencer keyframing, Movie Render Queue, Path Tracer support, seamless cloud looping
• ✅ ue-uds-modifiers-configs-state — Sky Modifiers, Configuration Manager, save/load state, lens flare, post process components, interior + Player Occlusion, water level, on-screen UI
• ✅ ue-uds-performance-mobile-troubleshooting — perf levers, mobile + Feature Level, updating UDS, cache system (Static Properties / Hard Reset Cache), common runtime issues

• ✅ ue-udw-setup-and-state — weather state model, presets, Change Weather, Manual Weather State, sampling, event dispatchers, Actor Weather Status component
• ✅ ue-udw-random-seasons-temperature — Random Weather Variation, seasons (0–4), climate presets, temperature system, Temperature Volumes
• ✅ ue-udw-spatial-weather — Weather Override Volumes, Radial Storms, Weather Above Volumetric Clouds, Weather Mask Brush / Projection Box
• ✅ ue-udw-particles-lightning-wind-sounds — rain/snow/dust particles, collision modes, lightning (incl. strikable actor interface), wind systems, sounds, environment sounds (5.1 metasound)
• ✅ ue-udw-material-and-screen-effects — Surface Weather Effects, DLWE V3, Glass Rain Drips, Foliage Wind, Water Ripples, screen droplets/frost/distortion, Puddle Fluid Volume, drip splines, breath, icicles

Skill names and folders now use the ue- prefix so they are easier to identify alongside skills for other tools. For example, enhanced-input is now ue-enhanced-input. Names that already had the prefix, such as ue-cpp-fundamentals, are unchanged.

After updating, replace previously copied skill folders instead of keeping both versions. Update explicit skill invocations, configured paths, and saved discovery URLs to use the new names. Category IDs and reference filenames are unchanged.

See docs/skill-authoring-guide.md. In short:

• One skill = one folder under skills/; folder name must equal the name frontmatter.
• name: lowercase letters/digits/hyphens, ≤64 chars, no leading/trailing/double hyphens.
• description: ≤1024 chars, states what it does and when to use it, with searchable keywords.
• Keep SKILL.md under ~500 lines; push deep detail into references/.
• Ground claims in real 5.8 source paths; cite Engine/Source/... locations.
• Prefer C++ that compiles against 5.8; flag version-specific behavior.

Validate any skill against the spec with the skills-ref tool:

skills-ref validate ./skills/<category>/<skill-name>

Verify that every engine-source citation in the skills still exists on disk (run after editing skills, and when re-targeting a new engine version):

node scripts/check-citations.mjs            # all skills
node scripts/check-citations.mjs core/ue-gameplay-tags   # one skill

Set UE_ENGINE_ROOT if your engine install is not at the default path.

evals/tasks/ holds golden tasks for high-traffic skills — realistic prompts with checkable acceptance criteria, used to compare an agent's output with and without the skill loaded. See evals/README.md for the method and the UE 5.8 compile-check workflow.