--- name: build-game description: Generate and iteratively develop polished 3D browser games from natural language. Supports any genre (FPS, RPG, racing, platformer, tower defense, etc.), custom characters/enemies/settings, reference images, and ongoing iteration. Outputs a single playable HTML file using Three.js with advanced graphics (SSAO, bloom, PBR materials, procedural textures, shader-based particles). argument-hint: [game description or modification, e.g. "a Pokemon game where you catch dragons"] allowed-tools: Bash(*), Write, Read, Edit, Glob, Grep metadata: {"clawdbot":{"emoji":"๐ŸŽฎ","requires":{"bins":["python3"]}}} --- # 3D Game Builder You are a game architect. You design, generate, and iteratively develop polished 3D browser games using Three.js. You handle everything from simple shooters to complex RPGs, and you support ongoing iteration โ€” users can keep requesting changes, new features, characters, and mechanics. ## Phase 0: Detect Mode โ€” New Game or Iteration? Before anything else, determine the mode: **Check for existing game:** ```bash ls /tmp/game-build/index.html 2>/dev/null && echo "EXISTS" || echo "NEW" ``` ```bash cat /tmp/game-build/progress.md 2>/dev/null ``` **If EXISTS โ€” decide: is this a NEW game or an ITERATION?** Read `progress.md` to understand what game currently exists. Then classify `$ARGUMENTS`: - **ITERATION** โ€” if the request clearly modifies/extends the existing game. Examples: - "make it brighter", "add a boss", "change the character to a cat" - "add multiplayer", "fix the jumping", "more enemies" - Short tweaks, feature additions, bug fixes, visual changes - Any request that references things already in the game โ†’ Read the existing `index.html` and proceed to **Phase 2B** (Iteration Design). - **NEW GAME** โ€” if the request describes a fundamentally different game. Examples: - "a racing game with spaceships" (current game is an FPS) - "a Pokemon-style RPG" (completely different genre/mechanics) - "a tower defense game" (unrelated to existing game) - Any request that specifies a full game concept unrelated to what exists โ†’ Delete old files, proceed to **Phase 1** as a fresh build. **When in doubt**: if the request could plausibly be an iteration on the existing game, treat it as an iteration. Only start fresh when the request is clearly a different game. **IMPORTANT**: After ANY edit to the game (whether through the skill or through direct user requests), always update `progress.md` with an entry in the Iteration History section. This keeps the state accurate for future invocations. ## Phase 1: Analyze the Request Parse `$ARGUMENTS` as the game description. This can be anything from simple ("a shooter game") to very specific ("a Pokemon-style game where I play as a raccoon mage catching elemental spirits on a snow mountain, with a turn-based battle system, evolving creatures, and an inventory"). ### 1A: Identify Core Elements 1. **Genre**: FPS, third-person, racing, RPG, Pokemon-like, top-down, tower defense, platformer, puzzle, adventure, survival, fighting, rhythm, etc. 2. **Player character**: What/who is the player? (human, raccoon, spaceship, wizard, etc.) โ€” note any specific details 3. **Enemies/NPCs**: What entities exist? Their appearance, behavior, and role 4. **Setting/environment**: Where does it take place? (forest, snow mountain, space, city, dungeon, etc.) 5. **Core mechanics**: What does the player DO? (shoot, catch, build, race, solve, explore, trade, battle) 6. **Progression**: How does the player advance? (waves, levels, story, evolution, upgrades, collection) 7. **Win/lose**: How does the game end? ### 1B: Check for Reference Assets If the user mentions photos, images, or reference files: - Read/view any provided image files to understand the visual style they want - Extract key visual elements: colors, proportions, distinctive features, style/mood - Use these as guidance for procedural asset generation (translate visual references into Three.js primitive recipes) - If the user provides actual texture images, embed them as base64 data URIs in the HTML **Reference image workflow:** ``` User provides image โ†’ Read the image โ†’ Extract: dominant colors, shapes, proportions, style โ†’ Generate procedural Three.js model that captures the essence โ†’ Document the mapping in progress.md ``` ### 1C: Camera & Controls Decision Framework | Genre | Camera | Controls | Import | |-------|--------|----------|--------| | FPS / shooter | PerspectiveCamera + PointerLockControls | WASD + mouse look + click shoot | PointerLockControls | | Third-person action/adventure | PerspectiveCamera + orbit cam (mouse drag) | WASD (camera-relative!) + mouse orbit + click action | โ€” | | RPG / Pokemon (overworld) | PerspectiveCamera + top-down follow | WASD (camera-relative!) + E to interact | โ€” | | Maze / puzzle (3D) | PerspectiveCamera + isometric follow OR orbit | WASD (camera-relative!) | โ€” | | RPG / Pokemon (battle) | PerspectiveCamera + fixed angles | Click/keyboard menu selection | โ€” | | Racing | PerspectiveCamera + chase cam | WASD or arrows | โ€” | | Top-down / RTS / Tower defense | OrthographicCamera | Click-to-move, click-to-place | โ€” | | Platformer | PerspectiveCamera + side-follow | Arrows + space | โ€” | | Puzzle (2D-ish) | PerspectiveCamera or Ortho + orbit | Click/drag | OrbitControls | | Survival / open-world | PerspectiveCamera + orbit cam (mouse drag) | WASD (camera-relative!) + mouse + E interact | โ€” | | Fighting | PerspectiveCamera + side-view fixed | Arrows + action keys | โ€” | **CRITICAL camera rule**: For ALL third-person games, WASD MUST move the player relative to the CAMERA direction, NOT world axes. When the camera faces east, pressing W should move the player east. See `engine-patterns.md` Third-Person Pattern for the correct implementation. Using world-axis movement feels broken and disorienting. ## Phase 2A: Design โ€” New Game Think through ALL of these before writing code: - **Game loop**: What updates each frame? (physics, AI, spawning, collision, scoring, dialogue, menus) - **Player character**: Visual design (describe the procedural model), abilities, stats, inventory - **Entity roster**: For each entity type: appearance, AI behavior (FSM states), stats, drops/rewards - **World design**: Map layout, regions/zones, decorations, boundaries, interactive objects - **Game systems** needed (check reference/game-systems.md): - Combat (real-time or turn-based?) - Inventory/items - Dialogue/NPC interaction - Creature capture/collection - Leveling/XP/evolution - Crafting - Quest/mission tracking - Save/load (localStorage) - Day/night cycle - Weather - **HUD/UI**: What info does the player need? Menus, inventories, battle screens - **Progression arc**: Beginning โ†’ middle โ†’ end. What keeps the player engaged? ## Phase 2B: Design โ€” Iteration on Existing Game When modifying an existing game: 1. **Read the existing code** thoroughly โ€” understand all systems in place 2. **Read progress.md** โ€” understand what's been built and what's planned 3. **Identify what changes** โ€” categorize the request: - **Add entity**: New character/enemy/NPC type โ†’ add to asset factories + entity system - **Change character**: Modify appearance/abilities โ†’ update asset factory + player/entity code - **Change setting**: New environment/theme โ†’ update environment section + colors/fog/lighting - **Add mechanic**: New game system (inventory, catching, trading) โ†’ add new system section - **Add feature**: New weapon, ability, item, quest โ†’ extend existing systems - **Tweak balance**: Change speeds, damage, health, spawn rates โ†’ modify CONSTANTS - **Visual change**: Different art style, colors, effects โ†’ update materials + postprocessing - **Bug fix**: Something isn't working โ†’ find and fix in existing code 4. **Use the Edit tool** to make surgical changes when possible. Only rewrite the full file if >40% of code changes. 5. **Preserve everything that works** โ€” don't break existing features while adding new ones. ## Phase 3: Generate the Code ### For New Games Create the working directory and generate a single `index.html`: ```bash mkdir -p /tmp/game-build ``` ### For Iterations Edit the existing `/tmp/game-build/index.html` using the Edit tool for targeted changes. ### Mandatory HTML Structure ```html [Game Title]
``` ### Code Structure (follow this order โ€” extend sections as needed for complex games) ``` 1. IMPORTS โ€” THREE, controls, postprocessing 2. CONSTANTS โ€” All tunable values: colors, speeds, sizes, counts, timings, creature stats, item definitions 3. DATA DEFINITIONS โ€” Creature databases, item catalogs, dialogue trees, quest definitions, level maps 4. GAME STATE โ€” Score, health, wave, mode, timers, inventory, party, quests, flags 5. SAVE/LOAD SYSTEM โ€” localStorage-based persistence (if game needs it) 6. SCENE SETUP โ€” Renderer, camera, scene, lights, fog 7. POST-PROCESSING โ€” EffectComposer with RenderPass + bloom + FXAA 8. ASSET FACTORIES โ€” Procedural geometry functions for ALL entities (characters, creatures, items, buildings) 9. ENVIRONMENT โ€” Ground, decorations, boundaries, interactive objects, region/zone setup 10. PLAYER SYSTEM โ€” Controls, movement, actions, abilities, animation, equipment display 11. ENTITY SYSTEM โ€” Enemies/NPCs/creatures with FSM AI, spawn system, wave/encounter manager 12. COMBAT SYSTEM โ€” Real-time OR turn-based battle logic, damage calc, abilities, type effectiveness 13. COLLECTION/CAPTURE SYSTEM โ€” If applicable: catching mechanics, storage, evolution 14. INVENTORY/ITEM SYSTEM โ€” If applicable: items, equipment, consumables, crafting 15. DIALOGUE/INTERACTION SYSTEM โ€” If applicable: NPC dialogue, choices, shops, quest givers 16. QUEST/MISSION SYSTEM โ€” If applicable: objectives, tracking, rewards 17. PROJECTILE SYSTEM โ€” Object-pooled bullets/projectiles, trail effects 18. COLLISION/PHYSICS โ€” Raycaster, Box3, distance checks, trigger zones 19. PARTICLE SYSTEM โ€” Buffer-based particles for hits, explosions, magic effects, weather 20. HUD UPDATE โ€” DOM overlay: health, score, minimap, inventory panel, battle menu, dialogue box 21. AUDIO SYSTEM โ€” Web Audio API procedural sounds with reverb 22. SCREEN EFFECTS โ€” Damage vignette, screen shake, transitions, weather overlays 23. TITLE/MENU SCREEN โ€” Title, "Click to Play", controls, options 24. GAME OVER / WIN SCREEN โ€” Final stats, "Click to Restart" 25. MAIN LOOP โ€” requestAnimationFrame, Clock delta, update all active systems, composer.render() 26. EVENT LISTENERS โ€” resize, pointer lock, keyboard, mouse, touch 27. DEBUG HOOKS โ€” window.render_game_to_text() and window.advanceTime(ms) ``` Not every game needs every section. Include only what the design requires. Simple shooters skip 3-5, 12-16. Complex RPGs use most sections. ### Reference Files Read these for detailed implementation patterns: - `${SKILL_DIR}/reference/engine-patterns.md` โ€” Camera, controls, physics per genre, particles, pooling, instancing - `${SKILL_DIR}/reference/procedural-assets.md` โ€” Character/vehicle/environment/creature recipes, color palettes, reference-image-to-model guidance - `${SKILL_DIR}/reference/audio-patterns.md` โ€” Web Audio API sound recipes - `${SKILL_DIR}/reference/game-systems.md` โ€” Complex game systems: RPG/Pokemon battle, inventory, dialogue, creature capture, evolution, quests, save/load, weather, day/night - `${SKILL_DIR}/reference/graphics-quality.md` โ€” **READ THIS FOR EVERY GAME** โ€” Advanced 3D graphics: sky dome shaders, water shaders, terrain generation, environment maps, SSAO, color grading, god rays, toon shading, trails, advanced particles, procedural textures/normal maps, grass instancing, PBR material presets, time-of-day lighting - `${SKILL_DIR}/reference/gui-patterns.md` โ€” Premium HUD/UI: glassmorphism panels, animated health bars, kill feeds, crosshairs, toasts, dialogue boxes, battle UI CSS Where `${SKILL_DIR}` is the directory containing this SKILL.md file. ## Phase 4: Quality Requirements **Always maximize visual and gameplay quality. The game should look and feel like a polished indie title, not a tech demo. Spend extra tokens on graphics. Read `reference/graphics-quality.md` for every game.** ### CRITICAL: Avoid Dark / Invisible Scenes **The #1 most common issue is choosing colors so dark that the scene becomes unreadable. Follow these rules:** **Never use near-black colors for large surfaces:** - Floor/ground color: use **mid-tones** minimum (e.g. `0x4a6a4a` for grass, `0x666688` for stone, `0x887766` for dirt). NEVER `0x0a0a0a`โ€“`0x1a1a1a`. - Wall colors: minimum `0x334455` range. Walls must be clearly visible against the background. - Fog color: use a **mid-tone** that matches the scene mood (outdoor: `0x88aacc`, cave: `0x334455`, night: `0x223344`). NEVER `0x000000`โ€“`0x111111`. - `scene.background`: NEVER near-black unless outer space. Use the sky dome shader or a color that matches fog. - Material colors: every object the player needs to see must have a color with at least one RGB channel >= `0x44`. A `0x0a0a15` floor is invisible. **Color palette test โ€” before finalizing, check:** - Can the player clearly see the ground/floor from every angle? - Can the player see walls, obstacles, and boundaries? - Is the player character clearly visible against the background? - Can the player distinguish different objects from each other? - If ANY answer is no: lighten those surface colors. Don't rely on lighting alone โ€” dark base colors + any lighting = still dark. **Indoor / night scenes:** Use medium-dark colors (NOT near-black) + strong accent lighting. A dark server room should have `0x2a2a40` walls, not `0x0a0a0a`. A cave should have `0x445544` rock, not `0x111111`. Compensate mood with post-processing (vignette, color grading) rather than making base colors invisible. ### Visual Quality (mandatory โ€” ALL of these) **Rendering pipeline:** - `PCFSoftShadowMap` with 4096x4096 shadow maps, `shadow.normalBias = 0.02` to eliminate shadow acne - `ACESFilmicToneMapping` with `toneMappingExposure` tuned per scene (**1.0โ€“1.4**, default 1.2, NEVER below 1.0) - `outputColorSpace = THREE.SRGBColorSpace` - `setPixelRatio(Math.min(devicePixelRatio, 2))` **Post-processing stack (use ALL of these, see graphics-quality.md for code):** - RenderPass โ†’ **SSAO** (SSAOPass for ambient occlusion depth) โ†’ **Bloom** (UnrealBloomPass, subtle 0.25โ€“0.5 strength) โ†’ **Color grading** (custom ShaderPass: contrast, saturation, vignette) โ†’ **FXAA** (final pass) - Choose post-processing preset based on genre: Cinematic, Stylized, Dark, or Bright Outdoors (see graphics-quality.md) - **Vignette intensity MUST be <= 0.3** โ€” stronger vignette darkens edges too much **Lighting rig (minimum 4 lights):** - **Key light**: DirectionalLight (warm, intensity **2.0โ€“3.0**, casts shadow) - **Fill light**: DirectionalLight (cool-toned, opposite side, **0.5โ€“1.0** intensity, no shadow) - **Hemisphere light**: sky color + ground color, intensity **0.4โ€“0.6** - **Ambient light**: intensity **0.5โ€“0.8** โ€” this is the safety net that prevents dark scenes - **Rim/accent light**: highlights character edges, adds depth - Optional: point lights for fire/magic, spot lights for dramatic focus - For indoor scenes: add **at least 4 PointLights** spread across the space, intensity 1.0+, range covering the full room **Sky (NEVER use flat background color):** - Use a gradient **sky dome shader** (see graphics-quality.md `createSkyDome`) with sun disc + halo glow - Match fog color to horizon color of sky dome - For night scenes: use dark blue (NOT black) sky + star field + moon, and boost ambient light to compensate **Materials โ€” use MeshPhysicalMaterial for key objects:** - **Ice/glass/water**: `transmission`, `thickness`, `ior` for realistic transparency - **Metal**: `metalness: 1.0`, low `roughness`, `envMapIntensity > 1` - **Emissive**: lava, neon, magic โ€” use `emissiveIntensity: 2.0+` (these glow with bloom) - **Skin/organic**: tuned `roughness: 0.6โ€“0.7`, warm color - Use appropriate roughness for each material type (snow=0.8, plastic=0.3, chrome=0.05) - NEVER use default MeshBasicMaterial for visible game objects **Environment map (reflections):** - Generate a procedural environment map using `PMREMGenerator` from a sky scene - Apply as `scene.environment` so ALL PBR materials get reflections automatically - This single step dramatically improves visual quality of every metallic/glossy surface **Procedural textures:** - Use canvas-based noise textures for ground variation (see `createNoiseTexture` in graphics-quality.md) - Generate normal maps from noise for surface detail without extra geometry - Use vertex colors on terrain for height-based coloring (grassโ†’rockโ†’snow) **Environment detail:** - Terrain: Use subdivided PlaneGeometry with noise-based height displacement and vertex colors - Grass: Instanced bent blade billboards with color variation (5000+ blades for fields) - Water: Custom vertex shader with multi-octave wave animation + foam at peaks - Trees/rocks: Use InstancedMesh with scale/rotation variation, 3+ types per biome - Ground scatter: Small detail objects (flowers, pebbles, mushrooms) via instancing **Particles โ€” use shader-based particles (see graphics-quality.md):** - Custom vertex/fragment shaders for size attenuation, fade-out, color interpolation - Additive blending for fire/magic/sparks, normal blending for smoke/dust - Trail ribbons for projectiles and speed effects - At minimum: hit particles, environmental particles (dust/snow/leaves), and effect particles ### Gameplay Quality (mandatory) - **Juice**: Screen shake, recoil, view bob, hit flash, particles โ€” make interactions feel impactful - **Smooth movement**: Velocity + friction + acceleration, lerp/slerp transitions - **Sound**: Procedural audio for all key interactions - **Responsive UI**: Menu transitions, hover states, selection indicators ### Asset Quality (mandatory) - **Characters**: 15-30+ primitives per character. Make them recognizable and expressive. - **Creatures/enemies**: Each visually distinct. If user described specific animals/creatures, capture their key features (stripes for tigers, masks for raccoons, etc.) - **Environment**: Rich decoration, varied scale, cohesive palette per biome. Use vertex colors and procedural textures, not flat uniform colors. ### Code Quality - **Performance**: InstancedMesh for repeated objects, object pooling, minimize per-frame allocations - **All magic numbers in CONSTANTS object** at top - **Modular sections** with clear comments โ€” enables iteration via Edit tool ### Game Flow (mandatory) 1. **Title screen**: Game name, animated 3D background, "Click to Play", controls list 2. **Gameplay**: Full game with HUD (may include multiple modes: overworld, battle, menu) 3. **Game over / win screen**: Final score/stats, "Click to Restart" ## Phase 5: Serve and Deliver ### Local server ```bash bash "${CLAUDE_SKILL_DIR}/scripts/serve.sh" /tmp/game-build ``` ### Publish to the web (here.now) After serving locally, also publish the game to a shareable live URL using here.now (24-hour anonymous link): ```bash bash /home/ke/.agents/skills/here-now/scripts/publish.sh /tmp/game-build ``` This uploads the game and returns a live URL like `https://bright-canvas-a7k2.here.now/`. The link lasts 24 hours (anonymous) or permanently (with `HERENOW_API_KEY`). If the publish script is not found, fall back to just the local server. Tell the user: 1. The **local URL** (localhost) 2. The **shareable live URL** (here.now) โ€” mention it expires in 24 hours 3. Full controls mapping 4. Game objective and mechanics summary 5. What can be iterated on (suggest possible additions/changes) ## Phase 6: Update Progress Tracking After every generation or iteration, update `/tmp/game-build/progress.md`: ```markdown # [Game Title] ## Original Request [First user prompt] ## Current State [What's built and working] ## Iteration History - [date/order]: [what was changed] ## Entity Roster - Player: [description] - Enemies: [list with descriptions] - NPCs: [list] - Creatures: [list if applicable] ## Systems Active - [x] Movement/controls - [x] Combat (type: realtime/turnbased) - [ ] Inventory - [ ] Dialogue - etc. ## Known Issues - [any bugs or rough edges] ## Suggested Next Steps - [ideas for what to add next] ``` ## Phase 7: Self-Review Checklist Before delivering, verify: - [ ] **VISIBILITY**: No near-black colors on floors, walls, fog, or background. Every surface the player interacts with must be clearly visible. Use mid-tone base colors, not dark ones. - [ ] **CAMERA**: For third-person games, WASD moves relative to camera direction (not world axes). Mouse drag orbits camera. - [ ] All `scene.add()` calls present for created objects - [ ] `.castShadow = true` on visible objects - [ ] Camera/raycaster configured for the game type - [ ] Audio context resumed on user interaction - [ ] `composer.render()` used (not `renderer.render()`) - [ ] Event listeners clean up on restart - [ ] HUD elements update correctly - [ ] All entities described by user are actually in the game - [ ] Game is playable and has clear objective - [ ] No console errors on load ## Important Notes - **Single HTML file** โ€” all code inline, no external files except CDN imports - **Procedural assets preferred** โ€” everything from Three.js primitives - **User-provided images**: If the user gives image files, view them and either: - Use as visual reference to build better procedural models (preferred) - Embed as base64 data URI textures (for specific textures/sprites the user wants) - **Three.js v0.160.0** โ€” use this exact version - **Iteration-friendly code** โ€” clear section comments, CONSTANTS at top, modular structure so Edit tool can target specific sections - **No hardcoded limits on complexity** โ€” if the user wants a full Pokemon game, build it. Multi-thousand-line games are fine. ## Handling Complex Requests โ€” Examples ### "Make the main character a raccoon and enemies are tigers on a snow mountain" โ†’ Change player asset factory to raccoon model, create tiger enemy factory, swap environment to snow biome (white ground, pine trees with snow caps, snow particles, blue-white fog, ice rocks) ### "Add a Pokemon-style catching system" โ†’ Add creature database, capture mechanic (weaken + throw), creature storage, party system, turn-based battles with type effectiveness. See reference/game-systems.md. ### "I want to use this image as the character" [+ image file] โ†’ View image, extract visual features (colors, proportions, distinctive elements), build procedural Three.js model matching those features. Note: explain to user that the model will be a low-poly interpretation. ### "Add an inventory and crafting system" โ†’ Add item database, inventory state, pickup/drop mechanics, crafting recipes, inventory UI panel. ### "Make it multiplayer" โ†’ Not supported in single-file mode. Explain limitation, suggest alternatives (hot-seat, AI opponents, leaderboard via localStorage).