---
name: generate2dmap
description: Plan and build 2D game maps and scenes - top-down and side-scrolling levels, tilemaps, prop packs, parallax backgrounds and HD-2D battle or story plates - with collision, navigation and reachability checks, environment motion, a playable HTML preview and export to Tiled, Godot 4 or LDtk. Map art (terrain, tiles, props, plates, parallax layers) is image generation by default, through generate2dmedia route_media.py (the API when a key is configured, else the local Codex or Grok CLI); map data (layout, collision, exits, spawns) is written as data. Use for any map, level, room, scene, background, terrain or prop-kit request. Not for characters, creatures, items or FX (generate2dsprite), character animation (video2dsprite), code-drawn tiles or maps (codeart2d, only on request) or calling an image or video API by itself (generate2dmedia).
---

# Generate 2D Map

Build the smallest scene bundle the request needs, in the game's art, camera, renderer and data conventions.
A background picture needs no game system; a playable map needs explicit geometry and data beyond a painting.

## Use when

- A playable map, level, room set, tilemap, terrain or prop kit, with collision and exits.
- A parallax background, a battle, title or story backdrop, or an HD-2D plate with lights and motion.
- Map data must be validated, previewed or exported to Tiled, Godot or LDtk.

## Do not use when

- Actors, items and attack FX: [generate2dsprite](../generate2dsprite/SKILL.md). Character motion from video: [video2dsprite](../video2dsprite/SKILL.md).
- Code-drawn tiles, layouts or parallax the user asked for: [codeart2d](../codeart2d/SKILL.md). Only an API or CLI call: [generate2dmedia](../generate2dmedia/SKILL.md).

## Capability check (once per session)

Run `python "<skill-dir>/../generate2dmedia/scripts/forge_doctor.py" --host-tools <tools> --save <output>/doctor.json`, where `<tools>` lists the media tools in your own tool list (`image_gen`, `image_edit`, `image_to_video`) or `none`. Its `ROUTES` block shows which API keys are configured (yes or no), the local readiness and the resolved order. If `encoding.stdout` fails, set `PYTHONUTF8=1`.

## Art source

Image generation is the default for map art: terrain and tile sheets, prop kits, HD-2D plates, painted backgrounds and parallax layers. Map data (layout, collision, exits, spawns) is data you write and validate, not art. Record each asset's `art_source` (`api`, `host_image`, `existing`, or `code` only on request) and name the route in your reply. A route the user names explicitly wins.

1. **API**, when a key is configured: OpenAI (`OPENAI_API_KEY`), Google Gemini (`GEMINI_API_KEY`), xAI (`XAI_API_KEY`), BytePlus Seedream (`ARK_API_KEY`) or fal.ai (`FAL_KEY`), in the environment or the user config file ([route-media.md](../generate2dmedia/references/route-media.md)). The configured key is the owner's consent, so there is no per-call question.
2. **Local**: your own image tool (Codex `image_gen`, Grok's native tool) when you have one, otherwise the user's signed-in Codex CLI, then Grok CLI.
3. **codeart2d** (autotiles, layouts, stylized parallax, ambient loops) only when the user explicitly asks for code-drawn art, or when `route_media.py` prints `no-route` (exit 3). Then say "code-drawn, no image model".

Every image goes through one command: `python "<skill-dir>/../generate2dmedia/scripts/route_media.py" image --prompt-file <txt> --reference <png> --size 1536x1024 --out-dir <new>`; masked plate motion uses `route_media.py video`. Each prints one JSON line with `route`, `artifact`, `sha256` and `estimateUsd`. Existing art the user supplies is always welcome. Never claim a generation that did not happen; keep the prompt and contract and report a missing capability.

## Host notes

- **Codex:** `image_gen` is your own image tool; with no configured key use it and look at results with `view_image`. An image this session made that is not in the project: `python "<skill-dir>/../generate2dmedia/scripts/cli_media.py" adopt --codex-thread <thread-id> --output-dir <new>`. codeart2d and generate2dmedia are explicit-only: open their SKILL.md when this one routes there.
- **Claude Code:** no built-in image generator: `route_media.py` takes the API or the local CLIs. Look at every PNG you make with Read (debug overlays, previews); run tools with Bash; `<skill-dir>` is `${CLAUDE_SKILL_DIR}`.
- **Grok:** its native image and video tools are your own tools; use their real schema.

## Commands

Run each tool as one line from the user's project root: `python "<skill-dir>/scripts/<tool>.py" ...`. `<skill-dir>` is this skill's folder; sibling skills sit beside it (`<skill-dir>/../codeart2d`). Keep inputs and outputs inside the project. Every tool writes a new `--output-dir` (or a new `--output` file): it refuses an existing one, stages beside it and publishes only after its checks (`--strict-qc` / `--strict` publish nothing on failure). Success prints one JSON line; errors print `error: ...` and exit 1; usage errors exit 2. Needs Python 3.10+, numpy and Pillow (scipy recommended); ffmpeg 5.1+ for scene motion; node for the browser runtime. `--help` lists every flag.

## Plan before art

Record viewport and logical resolution, world extent, origin, camera and zoom, actor scale and footprint, routes, landmarks, interactions, exits and render order. Source pixels are not world units: measure returned sizes and declare uniform scale and anchors. Choose by behaviour ([map-strategies.md](references/map-strategies.md); starting values per genre in [map-presets.md](references/map-presets.md)):

- `scene_mode`: authored area, town or arena; terrain plus props and explicit geometry.
- `tile_mode` / `grid_mode`: repeated or editable terrain or cell rules; tiles plus layer data.
- `room_chunk_mode`: connected rooms from a shared kit with door sockets.
- `side_scroll_mode`: side-view scenery or a playable platform stage with movement geometry.
- `baked_scene_mode`: a complete battle, title or story picture, with optional hotspots or bounded motion.

Split objects only when interaction, depth, reuse, editing or motion needs it. Pixel art needs deliberate logical pixels and nearest scaling; HD-2D pairs pixel actors with painted plates and light.

## Pipeline

Block out navigation, make art and kit, place it, validate the data, preview, then export. A playable map is a `map_bundle.v2` ([layered-map-contract.md](references/layered-map-contract.md)).

| Need | Route |
|---|---|
| Props from a sheet | `extract_prop_pack.py --input <sheet> --rows R --cols C --labels a,b --output-dir <new>` (`--grid-rounding nearest`, `--auto-boxes`, `--boxes-file <json> --keep-canvas`, `--world-scale 3/8`, `--suggest-footprint ellipse`); place by `anchor_px` ([prop-pack-contract.md](references/prop-pack-contract.md)) |
| Terrain fills, overlays, iso or hex, Wang rows | `extract_terrain_tiles.py --strict-qc` (`--layer overlay`, `--shape iso-diamond`, `--wang NAME=A/B:MASKS`; `--edge-policy seamless` only for art meant to tile) |
| Platform caps and middles | `extract_platform_strip.py --strict-qc` ([side-scroll-scenes.md](references/side-scroll-scenes.md)) |
| Code-drawn autotiles, only on request | codeart2d `autotile_build.py` (seam-proven tileset manifest), then the exporters |
| A code-drawn playable map, only on request | codeart2d `layout_build.py` (writes map_bundle.v2), then `map_nav.py check` and the exporters |
| Draw order, contact anchors, placement audit | `compose_layered_preview.py --base <png> --placements <json> --output <png> --report <json>`; with `--bundle <map_bundle.json> --debug-overlay --audit-out <json>` look at both |
| Validate a playable map | `map_bundle.py validate --bundle <b>` (`map_bundle.py hash` fills sha256), then `map_nav.py check --bundle <b> --output-dir <new>` (`--link` each neighbour); review `nav-debug.png`; `map_nav.py query` tests one spot or move |
| Walk the map, check every route | `build_scene_preview.py --bundle <b> --output-dir <new> --verify`; attach `scene-snapshot.json` ([scene-preview.md](references/scene-preview.md)) |
| Export | `export_tiled.py export --bundle <b> --output-dir <new>` (`--embedded-variant` for Phaser); `export_godot.py --bundle <b> --output-dir <new>`; `export_ldtk.py --bundle <b> --output-dir <new>` ([engine-maps.md](references/engine-maps.md)) |
| Room chunks; side-scroll grammar | `validate_chunks.py --chunks <json> --output-dir <new>`; `validate_layout.py --layout <json> --output-dir <new>` |
| Parallax | `validate_parallax.py --spec <plan> --report <qa.json>` (declare `camera.pivot` and the `aspects` you ship); code-drawn layers on request: codeart2d `parallax_build.py` ([parallax-backgrounds.md](references/parallax-backgrounds.md)) |
| Fit a painting to the game size or floor | `conform_background.py conform --mode cover` or `--mode ground-fit`; subjects on every screen aspect: `conform_background.py validate-crops` |
| HD-2D plate | [hd2d-plates.md](references/hd2d-plates.md): plan `stage.json`, `scene_layout_guide.py`, generate with `guide.png` attached, then `validate_stage.py --stage <json> --output-dir <new>`; look at every `layout-*.png` |
| Lights, shadows, atmosphere | [hd2d-presentation.md](references/hd2d-presentation.md): `extract_scene_lights.py extract --stage <json>`, curate `lights.json` |
| Night, lit or damaged variant of a plate | `edit_locality_check.py --before <master> --after <variant> --stage <json> --edit-box <box>`; regenerate on failure |
| Water, fire, mist or cloth on a still plate | [background-scenes.md](references/background-scenes.md): `build_motion_mask.py --envelope-from <clip>`, `scene_motion.py build`, then `scene_motion.py qa` on the decoded file; code-drawn ripples or glow on request: codeart2d `ambient_bake.py` |
| Full-frame scene loop | generate2dsprite `assemble_frames.py` (`--static-regions`, `--loop-overlap K --ambient`) |
| Collision and paths in a web game | `references/runtime/map-runtime.mjs` (same rules as `map_nav.py`) |

## Acceptance

- A playable map is accepted only after `map_bundle.py validate` and `map_nav.py check` pass, and the `build_scene_preview.py` route check says `ok: true` for every route. map_nav proves reachability from data, not that collision matches the painted art.
- Compose with a representative actor at game scale; check spawn clearance, collider versus canopy, reciprocal portal arrivals, joins, repeat seams and camera coverage.
- With a plate the best stage status is `needs-visual-review`. Quote `scene_motion.py qa` numbers (decoded seam, frames, fps, keyint, bytes) before calling a loop seamless.
- Native alpha must keep purple; an RGB checkerboard is not transparency. Test devices before claiming mobile performance.
- Deliver originals and prompts with their provenance (route, model, `estimateUsd`), runtime assets and data, the preview and the checks run, with remaining limits.
- Report every WARN or FAIL check verbatim (id, value, threshold, files) from each published QA envelope; never say "all checks passed" when any published envelope has a warn.

## References

[map-strategies.md](references/map-strategies.md), [map-presets.md](references/map-presets.md), [layered-map-contract.md](references/layered-map-contract.md), [prop-pack-contract.md](references/prop-pack-contract.md), [side-scroll-scenes.md](references/side-scroll-scenes.md), [parallax-backgrounds.md](references/parallax-backgrounds.md), [background-scenes.md](references/background-scenes.md), [hd2d-plates.md](references/hd2d-plates.md), [hd2d-presentation.md](references/hd2d-presentation.md), [scene-preview.md](references/scene-preview.md), [engine-maps.md](references/engine-maps.md); data contracts in `references/schemas/map.schema.json`.