Open-source notices & CAD library replacement

This software makes use of facilities provided by Open CASCADE Technology. The browser uses occt-wasm 3.4.0 and Open CASCADE Technology 8.0.0. The wrapper uses its MIT license alternative; the compiled OCCT library uses LGPL 2.1 with the OCCT exception. These are not the same license.

Complete attribution and source index · Pinned sources and binary identity · LGPL 2.1 · OCCT exception · Wrapper MIT license

Additional retained notices: Three.js, PDF.js, RapidJSON, Emscripten, musl, compiler-rt, libc++, libc++abi, libunwind.

Library source and build inputs

Obtain both the pinned wrapper/build source archive and pinned OCCT fork source archive. The first archive does not contain its OCCT submodule. Use the fork commit above, not a different official OCCT release.

The exact builder definition, build implementation and release workflow identify Emscripten 5.0.3, RapidJSON 1.1.0 and build commands. Follow those source instructions and retain matching generated JavaScript and WASM. Upstream uses a mutable builder image; we do not claim a bit-identical reproducible rebuild.

Replace the browser library

In 3D analysis, expand “CAD kernel / open-source notices” and choose a trusted compatible WASM binary. This clears prior model evidence; reopen your STEP to run the replacement locally in a terminable worker. The analysis package records the replacement binary SHA-256. Restore the bundled kernel with the reset button. The interface must match occt-wasm 3.4.0; incompatible binary interfaces require matching glue/wrapper in a local build.

Library replacement is for inspection and development, not machining approval. No restriction is imposed by this application on reverse engineering for debugging modifications to the LGPL library. The library's license and exception govern that library.

Readable integration and local execution

Current reviewed-slot runtime, declarations and browser integration sources include a byte-verified source index and local recognition/replacement example. This selected-operation workflow remains virtual; completed software evidence is not machine approval. No private drawings or shop programs are included.

Download feature analyzer source, browser integration reference and local runner into one directory. The example below runs one millimetre STEP solid using the analyzer and local runner, with an optional compatible replacement library. The browser reference additionally imports the native display adapters. Source files stay local; results remain unapproved candidates.

npm install --save-exact occt-wasm@3.4.0
node run-local.mjs part.step
node run-local.mjs part.step replacement.wasm

Use Node.js 22 or newer. A changed wrapper ABI requires building and importing its matching package instead of the pinned package. The browser's 60-second worker timeout is not provided by the CLI example. These are technical source/replacement instructions, not a legal-compliance certification.

Native SLDPRT display adapter

The independently implemented bounded reader uses the documented display-cache format, not an exact proprietary solid kernel. Format research: cadmpeg (format documentation CC BY 4.0; code Apache 2.0) and swformat (Apache 2.0). No customer drawings are distributed with these sources.