OCCTSwiftAIS

High-level Application Interactive Services for the OCCTSwift / OCCTSwiftViewport stack — selection-from-topology, manipulator widgets, dimension annotations, and standard scene objects, all in pure Swift.

Part of the OCCTSwift ecosystem — see the ecosystem map for how this package fits with the kernel, viewport, and sibling layers.

Current: v1.0.0. SemVer-stable from this tag, pinned alongside OCCTSwift v1.0.0 (OCCT 8.0.0 GA cohort). See SPEC.md for the design brief and docs/CHANGELOG.md for per-release notes.

What's in the box

• Selection-from-topology — pick a body / face / edge / vertex; round-trip the GPU pick to a TopoDS_Face / Edge / Vertex handle on the source Shape. Body and face highlights composite via the renderer's per-triangle style buffer (no overlay-mesh flicker).
• Manipulator widgets — translate and rotate gizmos with snapTranslate / snapRotateDeg, on the renderer's overlay layer (always-on-top), with native widget pick filtering. SwiftUI integration via .attachManipulator(_:).
• Dimensions — LinearDimension, AngularDimension, RadialDimension. Topology-aware anchors (vertex / edge midpoint / face bbox center / circular-edge center) feed into OCCTSwiftViewport's existing MeasurementOverlay for leader lines + billboarded label.
• Standard scene objects — Trihedron, WorkPlane, Axis, PointCloudPresentation.
• Selection survival — InteractiveContext.remap(_:using:rebindingTo:) translates a pre-mutation Selection to the post-mutation shape's indices via OCCTSwift's history records.

→ Getting started walks through wiring all of this into a SwiftUI app.

Installation

.package(url: "https://github.com/gsdali/OCCTSwiftAIS.git", from: "0.7.2"),

OCCTSwiftAIS transitively pulls OCCTSwiftTools, OCCTSwiftViewport, and OCCTSwift.

30-second example

import SwiftUI
import OCCTSwift
import OCCTSwiftViewport
import OCCTSwiftAIS

@MainActor
struct CADView: View {
    @StateObject private var ais = InteractiveContext(viewport: ViewportController())

    var body: some View {
        MetalViewportView(controller: ais.viewport, bodies: $ais.bodies)
            .onAppear {
                if let part = Shape.box(width: 10, height: 5, depth: 3) {
                    ais.display(part)
                }
                ais.selectionMode = [.face]
            }
            .onChange(of: ais.selection) { _, sel in
                for face in sel.faces {
                    print("selected face area:", face.area())
                }
            }
    }
}

Architecture

Application
   ↑
OCCTSwiftAIS         ← this repo (selection / manipulator / dimensions)
   ↑
OCCTSwiftTools       ← bridge: Shape ↔ ViewportBody
   ↑      ↑
OCCTSwift  OCCTSwiftViewport
(B-Rep)    (Metal)

OCCTSwiftAIS adds scene-management semantics an OCCT-style API expects (selection-on-topology, manipulators, dimensions) as a thin Swift layer on top of OCCTSwiftViewport's native Metal renderer. It is not a port of OCCT's TKV3d / TKService / TKOpenGl toolkits — see OCCTSwift/docs/visualization-research.md for why.

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

Same floor as OCCTSwiftViewport.

Documentation

• Getting started — selection, manipulators, dimensions, standard objects in one walkthrough.
• SPEC.md — design rationale and the v0.x → v1.0 trajectory.
• docs/CHANGELOG.md — what shipped in each release.

Sibling repos: OCCTSwift (B-Rep kernel), OCCTSwiftViewport (Metal renderer), OCCTSwiftTools (Shape ↔ ViewportBody bridge).

License

LGPL 2.1 (matching OCCT). See LICENSE.