SystemAssembly - OpenGeometry

class SystemAssembly A SystemAssembly is a node in the document, not a Three.js object. Add its bodies to your scene yourself.

import {
  OpenGeometry,
  Solid,
  SystemAssembly,
  OG_PRIMITIVE_CUBOID,
  OG_TRANSFORM_ROTATE,
} from 'opengeometry';

await OpenGeometry.create(
  { wasmURL: '/opengeometry_bg.wasm' },
  { workerURL: '/tessellation-worker.js' },
);

const shelf = new SystemAssembly({ ogId: 'shelf' });
new Solid(OG_PRIMITIVE_CUBOID, { width: 1, height: 0.02, depth: 0.3 }, { parent: shelf });
shelf.transform(OG_TRANSFORM_ROTATE, { axis: [0, 1, 0], degrees: 90 });
console.log(shelf.getChildren(), shelf.getWorldPlacement().xDirection);

Constructor

new SystemAssembly(options?: { ogId?: string; parent?: SystemAssembly })

Methods

Method	Returns
`transform(kind, params)`	`void`. Moves the assembly and everything under it
`getPlacement()`	`{ origin, xDirection, normal, scale }` relative to the parent
`getWorldPlacement()`	The same, in the world
`addChild(children, { keepWorld? })`	`void`. `children` are bodies or assemblies
`removeChild(child, { keepWorld? })`	`void`. With `keepWorld: true` the child keeps its world position
`getChildren()`	`string[]`, the children’s `ogId` values
`getParent()`	`string \| null`
`getBounds()`	`[minX, minY, minZ, maxX, maxY, maxZ]` of everything under it, or `null`
`dispose()`	`void`

Field	Type
`ogId`	`string`

An addChild that would make a node its own ancestor throws CycleDetected. A removeChild of a node that is not a child throws NotAChild. See Transforms and assemblies.

Last modified on November 10, 2026