> ## Documentation Index
> Fetch the complete documentation index at: https://invariant-cad.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Solid features

> Use extrude, revolve, Booleans, fillet, chamfer, shell, offset, and draft with explicit topology intent.

## Extrude and revolve

```ts theme={"system"}
const profile = cad.sketch("profile", plane.xy(), (sketch) =>
  sketch.profile(
    sketch.rectangle("outline", { width: mm(40), height: mm(20) }),
  ),
);

const extrusion = cad.extrude("extrusion", profile, {
  distance: mm(10),
  symmetric: true,
});

const revolution = cad.revolve("revolution", profile, {
  angle: deg(270),
  segments: 96,
});
```

Manifold additionally supports twisted and top-scaled extrusion:

```ts theme={"system"}
const twisted = cad.extrude("twisted", profile, {
  distance: mm(50),
  twist: deg(90),
  scaleTop: [scalar(0.75), scalar(0.75)],
  divisions: 32,
});
```

Check the [support matrix](/reference/support-matrix) before using these options
with another kernel.

## Booleans

Boolean features have one target and one or more tools:

```ts theme={"system"}
const joined = cad.union("joined", target, [toolA, toolB]);
const cut = cad.subtract("cut", target, [holeA, holeB]);
const common = cad.intersect("common", target, [clip]);
```

An empty tool array is rejected during authoring. The result is one solid; input
solids remain feature dependencies and are not mutated.

## Fillet and chamfer

Edge treatments require an explicit edge selection:

```ts theme={"system"}
const rim = topology.edges
  .createdBy(extrusion, { role: "extrude.edge.end-rim" })
  .exactly(4);

const rounded = cad.fillet("rounded", extrusion, {
  edges: rim,
  radius: mm(2),
});

const beveled = cad.chamfer("beveled", extrusion, {
  edges: rim,
  distance: mm(1),
});
```

The selection resolves against the direct input solid. A missing, ambiguous, or
wrong-cardinality selection fails before the treatment is applied.

## Shell and offset

```ts theme={"system"}
const endCap = topology.faces
  .createdBy(extrusion, { role: "extrude.face.end-cap" })
  .select();

const hollow = cad.shell("hollow", extrusion, {
  openings: endCap,
  thickness: mm(2),
  direction: "inward",
  tolerance: mm(1e-6),
});

const expanded = cad.offset("expanded", extrusion, {
  distance: mm(1),
  direction: "outward",
  tolerance: mm(1e-6),
});
```

Shell removes selected opening faces and offsets the remaining skin to create a
constant wall. Whole-solid offset has no opening selection. Both use positive
magnitudes plus an explicit direction.

## Draft

Draft is an atomic multi-face exact feature available through the matched owned
OCCT facade:

```ts theme={"system"}
const sides = topology.faces
  .createdBy(extrusion, { role: "extrude.face.side" })
  .atLeast(1);

const drafted = cad.draft("drafted", extrusion, {
  faces: sides,
  angle: deg(2),
  pullDirection: scalarVec3(0, 0, 1),
  neutralPlane: {
    origin: vec3(mm(0), mm(0), mm(0)),
    normal: scalarVec3(0, 0, 1),
  },
});
```

Stock OCCT does not advertise draft. Capability checks reject the feature before
input geometry is allocated on an unsupported backend.

## Exact-history boundary

Stock OCCT can construct most exact features, but its Boolean, edge-treatment,
and solid-offset topology history is partial. The optional owned facade
advertises complete bounded evolution only for the exact feature slices and ABI
versions documented in the [OpenCascade guide](/evaluation/open-cascade).

Construction success and complete topology evolution are distinct guarantees.