gsdali/occtswiftio

Headless CAD file I/O for OCCTSwift — STEP, IGES, STL, OBJ, BREP loaders + glTF/GLB/OBJ/PLY/STEP/BREP exporters. No Viewport dependency — safe to use from CLIs, batch pipelines, and server-side workflows that don't need a Metal renderer.

What it does

import OCCTSwift
import OCCTSwiftIO

// Load a STEP assembly into shapes + per-shape colors + AP242 dimensions/datums.
let result = try await ShapeLoader.load(from: stepURL, format: .step)
for (shape, color) in result.shapesWithColors {
    // ...
}

// Export to glTF / OBJ / STEP / BREP / PLY / GLB.
try await ExportManager.export(shapes: result.shapes, format: .glb, to: outURL)

For body-producing loaders (CPU mesh + interleaved vertex buffer + face/edge/vertex pick data for AIS), use OCCTSwiftTools which wraps this package with the bridge layer.

Architecture position

OCCTSwiftAIS          (selection / manipulators / dimensions; depends on Tools)
       ↑
OCCTSwiftTools        (bridge — Shape ↔ ViewportBody)
   ↑       ↑
   |   OCCTSwiftViewport  (Metal renderer)
   |
OCCTSwiftIO           ← this repo (headless file I/O)
       ↑
OCCTSwift             (B-Rep modeling kernel)

OCCTSwiftIO depends on OCCTSwift only. No transitive Viewport.

Installation

.package(url: "https://github.com/gsdali/OCCTSwiftIO.git", from: "0.1.0"),

Supported platforms

| Platform | Status | |---|---| | macOS 15+ arm64 | Supported | | iOS 18+ device + simulator arm64 | Supported | | visionOS 1+ device + simulator arm64 | Supported | | tvOS 18+ device + simulator arm64 | Supported |

Floor matches OCCTSwiftTools — change in lockstep if either moves.

Build & test

swift build
OCCT_SERIAL=1 swift test --parallel --num-workers 1

OCCT_SERIAL=1 + serial workers are required — there's a known NCollection container-overflow race in OCCT on arm64 macOS that segfaults parallel test runs. Inherited from OCCTSwift; do not "fix" by re-enabling parallelism.

License

LGPL 2.1 — matches OCCTSwift / OCCTSwiftTools.

Package Metadata

Repository: gsdali/occtswiftio

Default branch: main

README: README.md