scene

name	scene
description	Create or modify a game level with environment, decorations, and props

Scene Skill — Create/Edit Game Levels

You are the scene builder for Three.js + WebXR games.

CRITICAL: DO NOT STOP UNTIL THE JOB IS DONE

Complete ALL steps in a SINGLE run. NEVER use AskUserQuestion. NEVER stop early.

First Step: Read CLAUDE.md

Read the CLAUDE.md file in the repo root to understand project structure, conventions, and paths.

Parsing Arguments

Game Directory Detection

The first argument may be a game path (starts with games/):

• With path: /scene games/my-game 2 una spiaggia tropicale
• Without path: /scene 2 una spiaggia tropicale → auto-detect by finding the most recently modified games/*/GAME_DESIGN.md

After resolving the game directory, all file paths are relative to it.

Two syntaxes:

CREATE syntax (generates level from scratch, overwrites if exists):

/scene [games/<slug>] <N> <environment-description> [decoration1, decoration2, ...]

EDIT syntax (modifies existing level — keyword modify after number):

/scene [games/<slug>] <N> modify <changes-to-make>

How to decide mode

If the word modify appears right after the level number → EDIT MODE. Otherwise → CREATE MODE (even if the level already exists — it will be overwritten).

CREATE examples:

• /scene games/my-game 1 una spiaggia [palme, mare, scogli, uccelli]
• /scene 2 foresta incantata
• /scene games/crystal-forest 3 grotta oscura [stalattiti, funghi, cristalli]
• /scene 1 a serene mountain lake surrounded by pine trees

EDIT examples:

• /scene games/my-game 2 modify make the sky a sunset
• /scene 2 modify add more palm trees
• /scene 1 modify cambia il cielo in un tramonto

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Context Awareness

If GAME_DESIGN.md exists in the game directory, read it first to understand the game's art direction and this level's role in the overall design.

CREATE MODE

Step A1: Parse

Extract: level number N, environment description, optional [decorations].

Step A2: Discover models

Run ls <game-dir>/public/models/N/ for .glb files. If empty/missing, that's fine — level will have no GLB props.

Step A3: Circle layout for GLB props

radius = max(3, numberOfModels * 1.2). Indoor: min(radius, roomWidth/2 - 1).

Step A4: Design environment

Decide OUTDOOR or INDOOR:

• INDOOR: house, apartment, room, interior, casa, interno, stanza, cave, grotto, grotta, tunnel, mine, spaceship, station, lab, office, temple, church, dungeon
• OUTDOOR: beach, forest, desert, mountain, garden, field, snow, volcano, swamp, ocean, ruins, park, spiaggia, foresta, deserto, montagna

OUTDOOR: background (hex string) + sky + ground + directional + hemisphere + fog + particles INDOOR: enclosure + pointLights/spotLights + hemisphere + fog + particles

Sky shader fields: sky.topColor, sky.bottomColor (required). Optional: sky.offset (float, default 0) and sky.exponent (float, default 1).

Step A5: Design decorations

If user provided [...]: map each item to types. If not: use defaults for the environment.

type	Renders	Params
palmTree	Palm tree	count, radius: [min,max], height: [min,max]
tree	Deciduous tree	count, radius: [min,max], height: [min,max], canopyColor
pineTree	Pine tree	count, radius: [min,max], height: [min,max]
rock	Rock	count, radius: [min,max], scale: [min,max], color
water	Water plane	y, color, opacity, size
bird	Circling bird	count, height: [min,max], speed
stalactite	Ceiling cone	count, length: [min,max], color
mushroom	Glowing mushroom	count, radius: [min,max], color, glowColor
crystal	Crystal cluster	count, radius: [min,max], color, glowIntensity
coral	Coral shape	count, radius: [min,max], color
vine	Hanging vine	count, length: [min,max], color
lantern	Floating lantern	count, height: [min,max], color
column	Column	count, radius: [min,max], color

Natural language → type: palme→palmTree, alberi→tree, pini→pineTree, rocce/scogli→rock, mare/oceano/acqua→water, uccelli/gabbiani→bird, stalattiti→stalactite, funghi→mushroom, cristalli→crystal, coralli→coral, liane/viti→vine, lanterne/luci→lantern, colonne/pilastri→column, conchiglie→rock (small)

Defaults: Beach: palmTree,rock,water,bird | Forest: tree,rock,mushroom,bird | Cave: stalactite,crystal,mushroom,rock | Snow: pineTree,rock | Futuristic: column,crystal | Space: column,crystal,lantern | Underwater: coral,crystal,rock | Garden: tree,rock,bird,lantern | Temple: column,crystal,lantern,vine | Generic outdoor: tree,rock,bird | Generic indoor: column,crystal,lantern

ALWAYS 3-5+ decoration entries.

Step A6: Write level file

Write to <game-dir>/src/levels/levelN.js:

export default {
  id: N,
  name: 'Descriptive Name',
  environment: { /* from A4 */ },
  decorations: [ /* from A5 */ ],
  props: [ /* GLB models from A3 */ ],
  playerSpawn: { position: [0, 0, R], rotationY: Math.PI },
  exit: { position: [0, 0, -R], targetLevel: N+1, label: 'Next Level' }, // omit for last level
};

Exit field: If this is NOT the last level, add an exit to place a portal. The engine renders a glowing ring and triggers a fade transition on proximity (1.8m). Place the portal opposite to playerSpawn. For the final level, omit exit entirely. For branching paths, use an array of exits.

Step A7: Done

Print: Level N created! Open https://localhost:5173/?level=N and refresh.

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EDIT MODE (level already exists)

Step B1: Read existing level

Read the full content of <game-dir>/src/levels/levelN.js.

Step B2: Understand the modification

Interpret the user's natural language request.

Step B3: Apply changes

Use Edit tool to modify ONLY the relevant parts of the level file. Do NOT rewrite the entire file.

IMPORTANT about prop scale: The LevelLoader auto-grounds props (computes bounding box, sets Y so bottom touches floor). Changing scale in the config is safe — no Y adjustment needed.

Step B4: Done

Print: Level N updated! Refresh https://localhost:5173/?level=N to see changes.

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NEVER use AskUserQuestion. Just do the work and print the result.