Hi everyone
I wanted to share a CAD project I’ve been working on called BREP.

Live demo at https://BREP.io/

BREP is a feature-based modeling playground that explores BREP-style workflows on top of triangle meshes, running entirely in the browser. Instead of relying on traditional NURBS kernels, it combines robust manifold CSG on meshes with a lightweight face/edge representation, a full history pipeline, and real-time Three.js visualization.










What makes BREP different?
Mesh-first, feature-based workflow
Import STL/3MF meshes, repair and group triangles into faces, then continue modeling as if it were a traditional parametric solid.

Manifold CSG at the core
All boolean operations are backed by the excellent Manifold library, giving reliable results even with complex mesh inputs.

Full history system
Every operation is captured in a replayable history graph. Edit upstream features and downstream geometry updates automatically.

Runs entirely in the browser
No install required. The project is written in modern JavaScript and uses Three.js for visualization.

Current capabilities (high-level)
Parametric primitives (cube, cylinder, sphere, torus, etc.)

Sketch-based workflows (extrude, revolve, sweep, loft)

Fillets, chamfers, holes, shells, patterns

Image-based workflows (heightmaps, 2D image-to-face tracing)

Mesh import + repair

Assembly modeling with a constraint solver

PMI / annotation mode for manufacturing communication

Static build output suitable for CDN or simple web hosting

This is very much an experimental and evolving project. APIs are still settling, some areas are rough, and performance tuning is ongoing—but it’s already usable for real modeling tasks and for experimenting with alternative CAD architectures.

Who this might interest
People curious about CAD kernels and geometry pipelines

Anyone exploring browser-based CAD

Developers interested in feature history systems

Folks working with mesh-heavy workflows who want something more parametric

Links
Source repo: https://github.com/mmiscool/BREP

Docs & feature breakdown: included in the repo

Local dev: pnpm install && pnpm dev

Static build: pnpm build

I’m very interested in feedback, architecture discussions, and ideas—especially around mesh-based parametric modeling, history systems, and browser performance constraints.

If this direction resonates with you, feel free to poke around the repo or ask questions.
Edited 2025-12-24 07:44 by mmiscool

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