OpenCascade.js

FAQ

Fork status, maintenance model, and how to contribute to OpenCascade.js during the V3 / OCCT V8 release window.

Is this a fork of OpenCascade?

Yes — with nuance. @taucad/opencascade.js is a Tau-maintained fork of donalffons/opencascade.js, which itself is a port of upstream OpenCASCADE Technology (OCCT) to WebAssembly via Emscripten.

The fork exists to ship the V3 / OCCT V8 release while upstream is dormant. The intent is to merge back upstream into donalffons/opencascade.js via a single PR once V8 lands. During this window, issues and releases live at taucad/opencascade.js.

OpenCascade.js does not modify the OCCT C++ source beyond a small set of patches applied at build time. The pipeline downloads a tagged OCCT commit, compiles with Emscripten, auto-generates embind bindings from libclang, and ships the wasm + TypeScript surface as an npm package.

Who maintains it?

donalffons remains the maintainer-of-record for OpenCascade.js. Tau is the interim driver during the V3 / OCCT V8 release window — shipping docs, the GHCR Docker image, and the @taucad/opencascade.js@beta npm package until the merge-back PR lands.

How can I contribute?

Contributions are welcome and upstream-merge-back-aware:

  1. Open issues or PRs at taucad/opencascade.js.
  2. Follow the existing code style and test conventions in the repo.
  3. Prefer changes that will survive the upstream merge-back (OCJS-original branding, suffix-free V3 API, no Tau-specific forks of core bindgen logic).

For larger architectural questions, start a discussion before opening a PR.

First Shape Tutorial

Build a filleted box from scratch, render it in three.js, and inspect the OCCT call sites.

Projects using OpenCascade.js

Public projects and reference repositories built on OpenCascade.js.

On this page

Is this a fork of OpenCascade?Who maintains it?How can I contribute?