Primitives and transforms

Create boxes, cylinders, cones, spheres, and parameterized transform chains.

Primitives

const box = cad.box("box", {
  size: vec3(mm(40), mm(20), mm(8)),
  center: true,
});

const cylinder = cad.cylinder("cylinder", {
  height: mm(30),
  radius: mm(10),
  center: true,
  segments: 96,
});

const cone = cad.cylinder("cone", {
  height: mm(30),
  radius: mm(12),
  radiusTop: mm(4),
});

const sphere = cad.sphere("sphere", {
  radius: mm(10),
  segments: 64,
});

segments controls tessellation where a backend uses it. It does not turn an exact OCCT circle into a polygon; exact kernels can preserve analytic surfaces while using the value for mesh extraction where applicable.

All size, height, and radius expressions must resolve to finite valid geometry. The evaluator rejects zero or negative dimensions before asking a kernel to construct the shape.

One transform

const moved = cad.translate(
  "moved",
  box,
  vec3(mm(100), mm(0), mm(25)),
);

const turned = cad.rotate(
  "turned",
  moved,
  angleVec3(deg(0), deg(0), deg(90)),
);

Convenience methods are available for translation, Euler rotation, nonuniform scale, and mirror.

Ordered transform chain

Use cad.transform when operation order must be explicit:

const placed = cad.transform("placed", box, [
  tf.scale(scalarVec3(2, 1, 1)),
  tf.rotate(angleVec3(deg(0), deg(0), deg(90))),
  tf.translate(vec3(mm(100), mm(5), mm(0))),
]);

Operations execute in authored order. Reordering scale, rotation, and translation generally changes the result and therefore changes effective feature hashes.

Mirror

const mirrored = cad.mirror(
  "mirrored",
  placed,
  scalarVec3(1, 0, 0),
);

The vector is the mirror-plane normal. It must resolve to a usable finite direction. A zero normal is invalid.

Topology through transforms

Transforms create a new feature node, but semantic topology can retain origin and modification lineage when the selected backend provides it. Query for modifiedBy(transform) and combine it with the original feature source rather than using a post-transform coordinate alone.

Nonuniform scale changes metric geometry and may change analytic surface kinds. Persistent matching therefore depends on compatible evidence and the declared topology protocol, not merely on the fact that a transform node exists.