Reusable entities

The molen.entities content pack is Molen's curated entity collection. It builds on the existing renderable.kind: "gltf", molen/asset@1, molen/types@1, and molen/project@1 contracts; there is no second entity or asset runtime.

The initial nature collection contains pine, fir, oak, birch, shrub, and boulder models under the stable molen.entities.* namespace. Every model is a deterministic texture-free GLB with a hash-verified sidecar, meter-scale bounds, a conservative collision hull, and a type definition. The npm package @bendyline/molen-entities carries only the id lists and helpers, no models or type documents. Get the pack itself into a project with:

npx molen pack fetch https://molen.dev/packs/index.json molen.entities

That downloads the zip into packs/ and pins it in project.json's packs, so molen validate, sim run and the other ops resolve molen.entities.* types (molen project info lists them). Serve the same zip with your app for the browser. The headless capture ops (shot, drive, frames) draw only the models in the project's own assets today, so a pack model renders in the browser through the asset provider below but not yet in a CLI capture. The pack's source is content/entities/ in the engine repository, where its gallery scene is both an example and a headless render check.

Every concrete thing is authored as a logical source bundle under content/entities/source/<category>/<thing>/. Its local source.json inventories the definition, model master or recipe, scripts, textures, sounds, and documentation. The package generator builds the aggregate registry and gallery from those bundles; the aggregate files are compatibility and runtime outputs, not a second authoring authority.

Bind the pack to a browser client through its asset provider:

import { createClient } from '@bendyline/molen-client';
import { createPackSet, openPack } from '@bendyline/molen-pack';

// Wherever the app hosts the pack. Models are range-read only when a scene uses them.
const entities = await openPack('/packs/molen.entities.zip');
const client = await createClient(link, {
  assets: { provider: createPackSet([entities]).assetProvider() },
});

The entity type id and renderable asset ref are identical, such as molen.entities.tree.conifer.pine. For the type definitions, list the pack in the project's packs (see Projects & types); the CLI then resolves every molen.entities.* type. In code, read the documents the manifest provides as types and pass them to createTypeLibrary from @bendyline/molen-kernel/content.

In the engine repository, run molen asset list in content/entities, molen types check --project content/entities/project.json, or render content/entities/scenes/gallery.scene.json with molen shot. The package generator is deterministic and its build fails when a checked-in GLB, sidecar, types document, project, or gallery scene is stale.

Aircraft collection

molen.entities.aircraft.p51d and molen.entities.aircraft.oh6 add the Mustang and OH-6 helicopter, including GLBs, flight components and pilot seats. The pack's asset provider serves them like any other model. See Aircraft for world-view controls, physics and integration.

Transit and background traffic

molen.entities.transit.bus is a 12 m city bus, molen.entities.transit.lightrail a 27 m two-section light-rail car, and molen.entities.aircraft.airliner a narrow-body airliner. They are models for background traffic, not mountable vehicles. Ambient life spawns them through their ambientRole component, as it does the pack's five cars and the two aircraft above. In the engine repository, content/entities/scenes/transit.scene.json shows them side by side.