ShapeLoader

ShapeLoader is a headless CAD file loader. Its static methods load STEP / IGES / BREP / STL / OBJ / JWW into OCCT Shapes plus document metadata, returning a ShapeLoadResult. There is no Viewport dependency — renderable bodies live in OCCTSwiftTools, which wraps this package.

Topics

• ShapeLoadResult · ShapeLoader.load(from:format:progress:) · ShapeLoader.loadRobust(from:format:progress:) · ShapeLoader.loadFromManifest(at:)

ShapeLoadResult

The value returned by every ShapeLoader entry point: pure shape + document data.

public struct ShapeLoadResult: @unchecked Sendable {
    public var shapesWithColors: [(shape: Shape, color: SIMD4<Float>?)]
    public var dimensions: [DimensionInfo]
    public var geomTolerances: [GeomToleranceInfo]
    public var datums: [DatumInfo]
    public var manifest: ScriptManifest?

    public init(
        shapesWithColors: [(shape: Shape, color: SIMD4<Float>?)] = [],
        dimensions: [DimensionInfo] = [],
        geomTolerances: [GeomToleranceInfo] = [],
        datums: [DatumInfo] = [],
        manifest: ScriptManifest? = nil
    )

    /// Convenience: just the shapes, dropping color info.
    public var shapes: [Shape] { get }
}

• shapesWithColors — source shapes paired with a per-shape color, nil when the format carries no color (STL / OBJ / BREP / IGES).
• dimensions / geomTolerances / datums — AP242 GD&T extracted from the document (STEP only; empty otherwise). The element types (DimensionInfo, GeomToleranceInfo, DatumInfo) come from OCCTSwift.
• manifest — the decoded manifest, populated only by loadFromManifest.
• shapes — convenience accessor returning just the shapes.

ShapeLoader.load(from:format:progress:)

Loads a CAD file. STEP and IGES honour the progress observer; STL / OBJ / BREP loaders are single-call upstream and don’t surface progress.

public static func load(
    from url: URL,
    format: CADFileFormat,
    progress: ImportProgress? = nil
) async throws -> ShapeLoadResult

• Parameters: url — the file to load; format — the CADFileFormat selecting the code path; progress — optional ImportProgress observer (see ImportProgressClosure).
• Returns: a ShapeLoadResult with shapes, colors, and (for STEP) AP242 metadata.
• Throws: rethrows OCCTSwift import errors; ImportError.cancelled if progress.shouldCancel() returns true.
• Example:

  let result = try await ShapeLoader.load(from: stepURL, format: .step)
  for (shape, color) in result.shapesWithColors { print(shape, color as Any) }
  

ShapeLoader.loadRobust(from:format:progress:)

Robust variant — routes STL and IGES through the sewing/healing path (which closes gaps the basic importer can’t). For STEP / OBJ / BREP this is identical to load(from:format:progress:).

public static func loadRobust(
    from url: URL,
    format: CADFileFormat,
    progress: ImportProgress? = nil
) async throws -> ShapeLoadResult

• Parameters: as load(from:format:progress:).
• Returns: a ShapeLoadResult.
• Throws: rethrows OCCTSwift import / healing errors; ImportError.cancelled on cancellation.
• Example:

  let healed = try await ShapeLoader.loadRobust(from: igesURL, format: .iges)
  

ShapeLoader.loadFromManifest(at:)

Loads bodies from a script manifest (manifest.json + sibling BREP files). Resolves each BodyDescriptor.file relative to the manifest’s directory and skips entries whose file is missing. This entry point is synchronous throws, not async.

public static func loadFromManifest(at url: URL) throws -> ShapeLoadResult

• Parameters: url — the URL of the manifest.json document.
• Returns: a ShapeLoadResult whose manifest property holds the decoded ScriptManifest and whose shapesWithColors pairs each loaded BREP body with its BodyDescriptor.color.
• Throws: if the manifest can’t be read or decoded, or if a referenced BREP fails to load.
• Example:

  let result = try ShapeLoader.loadFromManifest(at: manifestURL)
  print(result.manifest?.bodies.count ?? 0, "bodies")