@bitbybit-dev/ifc-worker

The @bitbybit-dev/ifc library behind a web worker, so reading, authoring and writing IFC building models never blocks the page.

Beta. The API's names and inputs may still change before the first stable version.

Overview

Every method of @bitbybit-dev/ifc is here under the same dotted path, answering with a promise. Models live in the worker: a call that makes a model hands back a small handle, { hash, type: "ifc-model" }, which the next call takes in its place. A call made again with the same inputs is answered from the worker's cache, except the calls meant to differ each time: model.create without a seed and model.write without a timeStamp run every time.

The renderer packages (@bitbybit-dev/babylonjs, @bitbybit-dev/threejs, @bitbybit-dev/playcanvas) include it as bitbybit.ifc: their initBitByBit hands the worker you pass as workers.ifcWorker to bitbybit.ifcWorkerManager.setIfcWorker, and code that calls bitbybit.init itself makes that call too. Use this package directly when you want IFC without them.

The worker file

// ifc.worker.ts
import { initializationComplete, onMessageInput } from "@bitbybit-dev/ifc-worker";

initializationComplete();
addEventListener("message", ({ data }) => onMessageInput(data, postMessage));

Using it

import { BitByBitIFC } from "@bitbybit-dev/ifc-worker";

const bitbybit = new BitByBitIFC();
bitbybit.init(new Worker(new URL("./ifc.worker.ts", import.meta.url), { type: "module" }));

let model = await bitbybit.ifc.model.create({ name: "House", seed: "house-1" });
model = await bitbybit.ifc.spatial.addStorey({ model, id: "ground", elevation: 0 });
model = await bitbybit.ifc.walls.add({ model, storey: "ground", start: [0, 0], end: [6000, 0], height: 3000 });
const text = await bitbybit.ifc.model.write({ model, fileName: "house.ifc" });

With a renderer package's bitbybit object, draw a model by describing it as a recipe and building the recipe with the Manifold kernel:

const recipe = await bitbybit.ifc.geometry.recipe({ model });
const solids = await bitbybit.manifold.recipes.build({ recipe, adjustZtoY: true });
await bitbybit.draw.drawAnyAsync({ entity: solids });

ifcWorkerManager.ifcWorkerState$ reports the worker's state: loading once it is handed over, initialised once it has started, then computing and loaded as calls come and go. A worker whose script cannot load reports failed, and every call waiting on it is rejected.

To load the worker only when it is first needed, hand over a factory instead: ifcWorkerManager.setIfcWorkerFactory(() => new Worker(...)) makes the worker on the first IFC call, so a page that never calls the IFC library never downloads it. Until then the state is loaded, and startedTheRun and cleanAllCache answer at once, since there is nothing to clean.

IFCWorkerMock runs the library on the same thread through the same messages, each mock with models of its own and every message copied as a worker's would be, for tests and for scripts that need no worker.

Links

| Resource | URL | |----------|-----| | GitHub | https://github.com/bitbybit-dev/bitbybit/tree/master/packages/dev/ifc-worker | | Monorepo | https://github.com/bitbybit-dev/bitbybit | | NPM | https://www.npmjs.com/package/@bitbybit-dev/ifc-worker | | Documentation | https://learn.bitbybit.dev/learn/npm-packages/ifc | | Example | https://learn.bitbybit.dev/learn/code/common/ifc/family-house |