runtime-assets.md

Runtime asset options

RuntimeAssetOptions selects the catalog and adds browser asset loaders to the coordinator owned by a Runtime.

API

type RuntimeAssetCatalog = AssetCatalog | string | URL;

interface RuntimeAssetOptions {
  readonly catalog?: RuntimeAssetCatalog;
  readonly loaders?: Iterable<RuntimeAssetLoaderDefinition>;
}

interface RuntimeAssetLoaderDefinition<TValue = unknown> {
  readonly type: AssetType<TValue>;

  create(
    manager: THREE.LoadingManager
  ): AssetLoader<TValue>;
}

Catalog resolution

An omitted catalog creates an empty AssetCatalog. Passing an AssetCatalog uses that instance directly. String and URL inputs are fetched and parsed through AssetCatalog.parse() before the runtime is constructed.

An unsuccessful response rejects with an Error containing the catalog URL and HTTP status. Network errors, JSON decoding errors, and manifest validation errors propagate to the caller.

const runtime = await Runtime.create("canvas", {
  assets: {
    catalog: new URL("assets.json", document.baseURI)
  }
});

Loaders

Runtime starts from the engine's createDefaultAssetLoaders() registry: the model, font, audio, and texture loaders. Each custom definition receives the same Three.js LoadingManager available as runtime.manager.

A custom definition that uses an already registered asset type causes runtime construction to reject. See custom asset loaders for a complete setup.