The kernel does not load
What you see:OpenGeometry.create rejects, or the network panel shows a 404 for opengeometry_bg.wasm or tessellation-worker.js.
Cause: the page cannot fetch the two files. A bundler moved index.js without them.
Fix: copy both files into the folder your site serves at its root and pass their addresses. See Installation.
A call throws NotInitialised
Cause: a body was made before OpenGeometry.create finished.
Fix: await create once, before the first body.
The body is black
Cause: surfaces useMeshStandardMaterial, and the scene has no light.
Fix: add a light, for example new THREE.HemisphereLight(0xffffff, 0x444444, 2).
The body does not show
- Add the body to the scene. A body is not drawn on its own, and a
SystemAssemblyis not a Three.js object. - Render. Rendering is what asks the kernel for the mesh. Render in a loop, or render once,
await OpenGeometry.settled(), and render again.
A move is undone, with a PlacementOverwritten warning
Cause: the code set body.position, rotation or scale.
Fix: move bodies with transform. See Transforms and assemblies.
An edit throws SharedShape
Cause: the body is an instance, and its shape is shared with other instances.
Fix: pass { instances: 'all' } to change every instance, or call makeUnique() first to change only this one.
The profile comes out mirrored
Cause: on the default ground plane, a profile point[u, v] lands at world (u, 0, −v). The v axis runs along −Z.
Fix: flip the sign of v, or draw on another plane. See Coordinates and planes.
STEP export refuses the selection
Cause: a wire or a sheet cannot be exported on its own. It throwsInvalidOperand. A selection with no solid in it throws EmptyResult.
Fix: export solids. An assembly may also hold wires and sheets: they are left out and listed in report.skipped.
Every call throws after a fatal event
Cause: the kernel stopped after an internal failure.
Fix: call OpenGeometry.reset(), then make the bodies again. See Errors and limits.