Manifold backend

Manifold is the default InvariantCAD backend. InvariantCAD bundles the pinned standalone Manifold 3.5.1 core JavaScript and WebAssembly runtime, without its unrelated glTF/image toolchain.

Create directly

import { createEvaluator, createManifoldKernel } from "invariantcad";

const kernel = await createManifoldKernel();
const evaluator = await createEvaluator({ kernel });

Calling createEvaluator() without a kernel performs the same selection.

Custom WASM URL

const evaluator = await createEvaluator({
  manifold: {
    wasmUrl: new URL("/static/manifold.wasm", location.href).href,
  },
});

The runtime is initialized once per JavaScript realm. The first URL becomes the configured location. A later call with a different explicit URL fails because two incompatible global module instances would make ownership unclear.

Capabilities

The 0.1 adapter supports:

box, cylinder/cone, and sphere primitives
extrude and revolve
union, subtraction, and intersection
translation, rotation, scale, and mirror
twist/top-scale extrusion
mesh extraction, native measurements, and exact per-component mesh genus
binary/ASCII STL and OBJ through shared exporters

It does not advertise exact B-Rep, native STEP/BREP, semantic topology snapshots, exact fillets/chamfers/shells/offsets, lofts, or path sweeps.

Precision model

Manifold computes robust solids internally, but its public mesh carries Float32 vertex positions. Measurement methods call native Manifold volume, surface-area, bounding-box, and tolerance functions and combine those with bounded mesh integration for tensor properties. Genus is evaluated on every fresh component returned by decompose(), validated as a nonnegative safe integer, safe-summed, and cleaned up transactionally. That claim is exact for the Manifold mesh representation, not an assertion about a source B-Rep. A public mesh round-trip is not a lossless native shape codec. InvariantCAD therefore does not advertise shape-artifact persistence for Manifold 3.5.1.

Resource ownership

Each adapter shape wraps a native Manifold object. Feature intermediates and evaluated output shapes are deleted by the owning evaluation. Disposing the kernel releases any remaining live adapter shapes. The initialized Manifold module promise remains cached for the lifetime of the JavaScript realm.

Security and provenance

The bundled runtime bytes are pinned by SHA-256, verified during every build, and shipped with Manifold and embedded-component license notices. This avoids installing Manifold’s optional glTF/image dependency graph in consumers while preserving the exact tested core runtime. See third-party notices.

Getting started

Modeling

Evaluation

Analysis and interchange

Create directly

Custom WASM URL

Capabilities

Precision model

Resource ownership

Security and provenance

​Create directly

​Custom WASM URL

​Capabilities

​Precision model

​Resource ownership

​Security and provenance

Create directly

Custom WASM URL

Capabilities

Precision model

Resource ownership

Security and provenance