Default structure library

Molen ships 120 procedural structures: the original 16 styles and 104 additional interpretations of real-world buildings. They share 51 material graphs and the existing footprint-driven worldgen pipeline. Each entry has a stable style ID, taxonomy, country references, use, characteristic details, and a representative footprint and floor count. These are original stylized studies, not surveyed replicas or static meshes stretched to fit a parcel.

The generated runtime index is structures/catalog.json, shipped in the molen.worldgen.default content pack (role structures). All 120 styles are registered in the default style pack. The editable source for each logical building lives in its own copyable directory under source/structures/; its source.json inventories the local recipe or archstyle and definition metadata. Supporting architectural references are maintained in the collection-wide catalog.json in the engine repository. Get the pack itself with npx molen pack fetch https://molen.dev/packs/index.json.

See and reshape every structure

Open the structure library in the browser, or use the Explore 120 structures link in World Explorer. The collection renders the actual shipped generators and shared material graphs. Search by name, country, construction material or description; filter by taxonomy; select any card to change width, depth and storeys, orbit, compare front and rear, or inspect the silhouette without textures. The detail menu uses the production geometry tiers. The sheet shows complete exteriors; optional enterable interiors are generated separately by the world renderer.

Download model sheet exports all 120 rendered entries as a labeled PNG. For reproducible captures in the engine repository, build once and run:

pnpm -r build
node examples/world-explorer/scripts/capture-structure-sheet.mjs

This creates artifacts/building-diversity/model-sheet.png, 13 taxonomy sheets, front/rear/detail and resized inspection frames for six representative structures, and render-report.json with material failures, mesh counts and hashes. The report must contain 120 entries, 120 unique IDs, and no failed materials or browser errors. The full sheet is normalized to fit each card; dimensions beneath each study supply its real scale.

Taxonomies

Family	Examples
North American homes	Cape Cod, Craftsman, brownstone, ranch, timber barn
Latin American and Caribbean streets	Patio house, hacienda wing, sobrado, Chiloé shingles
Northern European vernacular	Nordic timber, croft, thatched farmhouse, boathouse
Western European town and country	Canal house, mansard apartments, half-timbered house
Mediterranean buildings	Palazzo, azulejo townhouse, Cycladic house, farmhouse
Eastern European and alpine buildings	Konak, timber cottage, gallery house, alpine inn
North African and West Asian buildings	Riad, courtyard house, earthen tower, stone house
African domestic and community buildings	Swahili house, Sahel townhouse, courtyard compound
South Asian buildings	Haveli, nalukettu, Newari townhouse, bungalow
East Asian buildings	Machiya, gassho farmhouse, hanok, siheyuan, square tulou
Southeast Asian buildings	Shophouse, tube house, timber house, limasan
Australian, New Zealand and Pacific buildings	Queenslander, villa, bach, community hall
Civic, commercial and working structures	Library, fire station, market, factory, clinic, retail

Place and resize a building

Supply a catalog entry's style to any normal BuildingRequest, worldgenBuilding component, worldgen batch, preview or bake operation. Regenerate with a new footprint to change width/depth; the wall bays, windows, roofs and ornament are rebuilt in meters. Changing levels changes the storeys; supplied height remains the total envelope. Transformed and nonrectangular footprints use the same analysis and safe roof fallback as existing styles.

const request = {
  identity: 'neighborhood:home-42',
  style: 'molen.worldgen.catalog.craftsman',
  labels: ['bungalow'],
  outline: [[0, 0], [16, 0], [16, 11], [0, 11]],
  levels: 2,
};
// generateWorldgenBatch({ buildings: [request], pack })

The default Earth atlas now has 45 geographic regions. Weighted variants sample a named stream of stable building identity, so reordering features or regenerating a tile preserves its style. Rules retain a fallback style; optional variants: [{ style, weight }] supplies the weighted pool. Explicit building styles win. Measured heights and floor counts are retained, and known tall buildings bypass low-rise residential variant pools. Geographic envelopes are broad visual priors and do not identify the architecture of an individual mapped building.

Architecture and material authoring

facade.details adds shutters, balconies, timber framing or pilasters, awnings and verandas. Details use the actual facade rhythm, a bounded perimeter allocation, and the existing facade-bands tier flag. Structural openings, clipped edges and courtyard constraints take precedence. Dormers use roof.features.dormers on eligible pitched wings. Simplified budget representations omit ornament while retaining their footprint, primary roof and measured envelope.

The standard material catalog groups all 51 shared graphs by construction. It includes several brick bonds, cut/rubble stone, clapboard and board-and-batten, shingles, clay tiles, slate, thatch, rammed earth and metal roofs. Physical repeat sizes live in scripts/standard-materials.mjs. Common textures are 256² and prepared once per shared material set. Window graphs use cell UVs; solid surfaces use meter UVs.

To vary a structure in your own project, copy its archstyle.json (or write a new one), preview it with npx molen worldgen preview my.archstyle.json --out preview.png, and ship your styles as your own style pack with molen pack build. Worldgen covers the format.

The library itself is maintained in the engine repository. Edit the applicable content/worldgen/source/structures/<style>/ bundle there. Generated styles use recipe.json; the original styles carry their complete archstyle.json. After editing, from the repository root:

node packages/worldgen/scripts/generate-structures.mjs
node packages/worldgen-earth/scripts/generate-structure-atlas.mjs
pnpm -r build
pnpm docs:gen
node examples/world-explorer/scripts/capture-structure-sheet.mjs

The worldgen build rejects stale generated catalog resources. Keep the model-sheet review in the loop: inspect roof silhouettes, window proportions, trim contrast, shadows and resized placements before accepting a recipe change. Kernel tests generate every entry repeatedly at independent footprint scales and a supplied height, and verify valid deterministic geometry.