Architecture - OpenGeometry

OpenGeometry has three parts. You call only the SDK.

Part	What it does
Kernel	Rust, compiled to WebAssembly. Holds every shape as an exact B-rep and runs the modelling and the exports.
SDK	TypeScript. Gives you `Wire`, `Solid`, `Sheet`, `SystemAssembly` and the `OpenGeometry` statics.
Display worker	A web worker that turns shapes into Three.js meshes, so the page stays responsive. It can also run inline.

One document

OpenGeometry.create starts one kernel with one document. Every body you make goes into it. OpenGeometry.reset() empties it. The document is a graph of nodes. A node is a body or an assembly, with a placement and an optional parent. A body points to a shape. Two instances can point to the same shape.

Exact shapes, display meshes

The kernel keeps exact geometry: planes, cylinders, cones, spheres, tori, lines, circles and arcs. Booleans, measurements and STEP export use this exact geometry. The meshes that you see are a separate, approximate copy, made for display only. The kernel makes them when the scene asks, at the level of detail that the camera needs. See Display.

Your scene stays yours

Every body is a THREE.Group with two children: a surface mesh and an outline line set. You add bodies to your own scene, with your own camera, lights and renderer. OpenGeometry makes no scene, no camera and no controls.

Calls are synchronous

Making and editing bodies is synchronous: a new Solid(...) or an operate(...) has finished when the call returns. Only create, settled and exportStep return promises.

Next

Bodies: wires, sheets, solids, shapes and instances.
Coordinates and planes: units, axes and where a profile lands.

Last modified on November 10, 2026