### Example: Print Hostname

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

An example demonstrating how to safely unwrap and print the hostname if available.

```swift
if let host = HostInfo.hostName { print("Running on \(host)") }
```

--------------------------------

### start()

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Math-Bounds.md

Start (or resume) the timer.

```APIDOC
## start()

### Description
Start (or resume) the timer.

### Method
`public func start()`

### Example
```swift
t.start()
```
```

--------------------------------

### Diameter Value Calculation Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/DrawingAnnotation.md

Example showing how to instantiate a Diameter and access its 'value' property to get the full diameter.

```swift
let d = DrawingDimension.Diameter(centre: .zero, radius: 8)
print(d.value)  // 16.0
```

--------------------------------

### Diameter Initialization Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/DrawingAnnotation.md

Example demonstrating how to create a Diameter instance with a specific tolerance and print its calculated value.

```swift
let diam = DrawingDimension.Diameter(
    centre: SIMD2(30, 30),
    radius: 10,
    tolerance: .fitClass("H7")
)
print(diam.value)  // 20.0
```

--------------------------------

### Iterate Through Materials Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document.md

An example demonstrating how to iterate through all materials in a document and print their names and densities.

```swift
for mat in doc.materials {
    print(mat.name, "density:", mat.density)
}
```

--------------------------------

### Example Usage of Helix.build

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Mesh-Fixing.md

Demonstrates how to build a helix using Helix.build and access its resulting curve and achieved tolerance. It prints the error and the starting point of the curve.

```swift
if let result = Helix.build(
    parameterRange: 0...(4 * .pi),
    pitch: 5,
    radius: 10
) {
    let curve = result.curve
    print("error:", result.toleranceReached)
    print("start:", curve.point(at: 0))
}
```

--------------------------------

### Example: Create a Torus in XY Plane

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Shape.md

An example demonstrating how to create a torus using the majorRadius and minorRadius parameters. The result is checked for nil.

```swift
if let ring = Shape.torus(majorRadius: 10, minorRadius: 2) { }
```

--------------------------------

### Find All Roots Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Math-Solvers.md

Example demonstrating `findAllRoots` to find all roots of sin(x) in the interval [0, 4π].

```swift
// Find all roots of sin(x) in [0, 4π]
let roots = MathSolver.findAllRoots(in: 0...4*.pi, samples: 40) { x in
    (sin(x), cos(x))
}
```

--------------------------------

### Example: Calculate Midpoint of Face UV Bounds

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Face.md

Demonstrates how to get the UV bounds of a face and calculate the midpoint within those bounds to find a corresponding 3D point.

```swift
if let uv = face.uvBounds {
    let uMid = (uv.uMin + uv.uMax) / 2
    let vMid = (uv.vMin + uv.vMax) / 2
    let center = face.point(atU: uMid, v: vMid)
}
```

--------------------------------

### DrawingDimension.Ordinate.Feature Initialization Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/DrawingAnnotation.md

Example demonstrating how to create a new DrawingDimension.Ordinate.Feature instance with a given position.

```swift
let f = DrawingDimension.Ordinate.Feature(position: SIMD2(35, 0))
```

--------------------------------

### Example: Set and Get Real and Comment Attributes

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document.md

Demonstrates setting a real attribute and a comment attribute on a newly created label, then retrieving and printing them. Ensure a label is successfully created before proceeding.

```swift
guard let label = doc.createLabel() else { return }
_ = label.setReal(3.14159)
_ = label.setComment("pi approximation")
print(label.real ?? 0, label.comment ?? "")
```

--------------------------------

### Point to Circle Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-BSpline-Extrema.md

An example demonstrating how to find the nearest point to a circle and calculate its distance.

```swift
let pts = ExtremaPointCurve.pointToCircle(
    point: SIMD3(0, 0, 5),
    center: .zero, normal: SIMD3(0, 0, 1), radius: 3
)
if let nearest = pts.min(by: { $0.squareDistance < $1.squareDistance }) {
    print(sqrt(nearest.squareDistance))
}
```

--------------------------------

### Get Edge Start Vertex

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/TopologyGraph-Detail-History.md

Retrieves the index of the start vertex for a given edge. Returns nil if the edge has no recorded start vertex.

```swift
public func edgeStartVertex(_ edgeIndex: Int) -> Int?
```

```swift
if let v0 = graph.edgeStartVertex(0) {
    let pt = graph.vertexPoint(v0)
}
```

--------------------------------

### Example: Initialize and Build PipeShellBuilder

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Geometry-Constructors.md

Demonstrates initializing a PipeShellBuilder with a spine wire, adding a profile, and building the shape.

```swift
if let pipe = PipeShellBuilder(spine: spineWire) {
    pipe.add(profile: profileWire)
    pipe.build()
}
```

--------------------------------

### Set Relation Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-OCAF-Attributes.md

An example demonstrating how to set a relation string for a label.

```swift
doc.setRelation(tag: 5, relation: "width = height / 2")
```

--------------------------------

### Get BSpline Start Point

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Curve2D-Analytic-Types.md

Retrieves the start point of the BSpline curve. Returns SIMD2<Double>.zero if the curve is not a BSpline.

```swift
public var bsplineStartPoint: SIMD2<Double> { get }
```

```swift
let s = curve.bsplineStartPoint
```

--------------------------------

### Example: Create Polygon3D with Parameters

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Shape-Recognition.md

Demonstrates creating a Polygon3D with both points and curve parameters, and checking for their presence.

```swift
let pts: [SIMD3<Double>] = [SIMD3(0,0,0), SIMD3(5,0,0), SIMD3(10,0,0)]
let params: [Double] = [0, 0.5, 1]
if let poly = Polygon3D.create(points: pts, parameters: params) {
    print(poly.hasParameters)  // true
}
```

--------------------------------

### Get Bézier Curve Start Point

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Curve3D-Analytic-Types.md

Retrieves the first pole (start point) of a Bézier curve. Returns .zero if the curve is not a Geom_BezierCurve.

```swift
public var bezierStartPoint: SIMD3<Double> { get }
```

```swift
if let curve = Curve3D.bezier(poles: [SIMD3(0,0,0), SIMD3(1,1,0), SIMD3(2,0,0)]) {
    let start = curve.bezierStartPoint  // SIMD3(0,0,0)
}
```

--------------------------------

### Run Visual Workflow Demos

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/integration-tests.md

Execute visual workflow demonstrations in OCCTSwiftViewport using the Swift Package Manager.

```bash
# Visual workflow demos (in OCCTSwiftViewport)
cd ../OCCTSwiftViewport
swift run OCCTSwiftMetalDemo --test-all-demos
```

--------------------------------

### Get Elapsed Time from OSD_Timer

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Math-Bounds.md

Retrieves the elapsed wall-clock time in seconds from the OSD_Timer. Ensure the timer has been started and stopped to get a meaningful value.

```swift
public var elapsedTime: Double { get }

```

```swift
t.start()
// ... work ...
t.stop()
print(t.elapsedTime)

```

--------------------------------

### Brent Minimization Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Math-Solvers.md

Example demonstrating how to use `minimizeBrent` to find the minimum of x² within the interval [-2, 2].

```swift
// Minimize x² in [-2, 2]
if let res = MathSolver.minimizeBrent(ax: -2, bx: 0.1, cx: 2) { x in
    (x * x, 2 * x)
} {
    print(res.location)  // ≈ 0
}
```

--------------------------------

### Get Curve2D Start Point

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Curve2D.md

Retrieves the starting point of the Curve2D based on its parameter domain. This is a convenience for accessing the point at the lower bound of the domain.

```swift
let seg = Curve2D.segment(from: SIMD2(1, 2), to: SIMD2(4, 5))!
print(seg.startPoint)  // SIMD2(1.0, 2.0)
```

--------------------------------

### Example: Make Solid

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Geometry-Constructors.md

Builds the pipe shell and then attempts to convert it into a solid by capping the ends.

```swift
pipe.build()
pipe.makeSolid()
```

--------------------------------

### TitleBlock Initialization Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Drawing.md

Demonstrates how to create a TitleBlock instance with common fields.

```swift
let tb = TitleBlock(
    title: "Mounting Bracket",
    drawingNumber: "MB-042",
    creator: "J. Smith",
    dateOfIssue: "2026-06-21",
    revision: "B",
    scale: "1:2"
)
```

--------------------------------

### Get Start Point of 2D Bézier Curve

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Curve2D-Analytic-Types.md

Retrieves the start point (first pole) of a 2D Bézier curve. Returns .zero if the curve is not a Bézier.

```swift
public var bezierStartPoint: SIMD2<Double> { get }
```

```swift
let s = curve.bezierStartPoint
```

--------------------------------

### Set Name on Main Label Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document.md

An example demonstrating how to get the main label of a document and set its name. This is a common operation for identifying the root of the document.

```swift
if let main = doc.mainLabel {
    _ = main.setName("MyModel")
}
```

--------------------------------

### Example: Getting Paper Size in Portrait Orientation

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Drawing.md

Shows how to get the dimensions of an A4 paper size when set to portrait orientation. This is useful for precise layout planning.

```swift
let sz = PaperSize.A4.size(in: .portrait)  // (210, 297)
```

--------------------------------

### Example Usage of StepHeader

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

Demonstrates initializing a StepHeader, setting author and organization, and checking if it's done.

```swift
if let header = StepHeader(filename: "part.stp") {
    header.author = "Alice"
    header.organization = "ACME"
    print(header.isDone)
}
```

--------------------------------

### Example: Wire Building

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Mesh-Fixing.md

Demonstrates creating a wire using WireBuilder by adding edges sequentially and checking for success or errors.

```swift
let builder = WireBuilder()
builder.addEdge(Shape.edgeFromLine(from: .zero, to: SIMD3(5, 0, 0))!)
builder.addEdge(Shape.edgeFromLine(from: SIMD3(5, 0, 0), to: SIMD3(5, 5, 0))!)
if builder.isDone, let wire = builder.wire {
    print("built wire with", wire.edges().count, "edges")
} else {
    print("error:", builder.error)
}
```

--------------------------------

### Example Usage of Cylinder-Sphere Intersection

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

Shows how to call the cylinder-sphere intersection function and print the number of resulting curves. This example assumes a basic setup and checks for a non-nil result.

```swift
if let n = QuadricIntersection.cylinderSphere(cylinderRadius: 3,
                                                  sphereCenter: .zero,
                                                  sphereRadius: 5) {
    print("\(n) intersection curve(s)")
}
```

--------------------------------

### Gauss Integration Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Math-Solvers.md

Example demonstrating `integrate` to calculate the area under the curve of sin(x) from 0 to π.

```swift
let area = MathSolver.integrate(from: 0, to: .pi) { x in sin(x) }
// ≈ 2.0
```

--------------------------------

### bsplineStartPoint

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Curve2D-Analytic-Types.md

Gets the starting point of the BSpline curve. This is the point at the first parameter value.

```APIDOC
## `bsplineStartPoint`

### Description

Retrieves the start point of the BSpline curve, corresponding to the first parameter value.

### Returns

- Start point as a `SIMD2<Double>`; `.zero` if not a BSpline.

### Example

```swift
let s = curve.bsplineStartPoint
```
```

--------------------------------

### Example Usage of ZLayerSettings.topOSD

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Display.md

Demonstrates how to use the predefined topOSD layer ID to place an object in a transparent overlay.

```swift
let overlayLayerId = ZLayerSettings.topOSD
```

--------------------------------

### Resolve ConstructionPlane Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Construction.md

Demonstrates how to resolve a `ConstructionPlane` recipe against a `TopologyGraph`. This example shows how to handle both successful resolution to a `Placement` and failure with a `ConstructionResolutionError`.

```swift
let plane = ConstructionPlane.absolute(origin: .zero, normal: SIMD3(0, 0, 1))
switch graph.resolve(plane) {
case .success(let p): print(p.origin, p.zAxis)
case .failure(let e): print(e)
}
```

--------------------------------

### Example: Querying Continuity Class

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Surface.md

Shows how to get the continuity class of a b-spline surface.

```swift
let bsp = Surface.bspline(poles: ..., ...)!
print(bsp.continuityClass)  // typically .c2
```

--------------------------------

### Volume Inertia Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Shape-Measurement.md

Example demonstrating how to access and print volume and gyration radii from a computed VolumeInertia object.

```swift
if let vi = solid.volumeInertia {
    print("volume: \(vi.volume)")
    print("gyration radii: \(vi.gyrationRadii)")
}
```

--------------------------------

### Example of Calculating Linear Dimension Value

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/DrawingAnnotation.md

Demonstrates how to access the 'value' property of a DrawingDimension.Linear to get the measured distance.

```swift
let lin = DrawingDimension.Linear(from: SIMD2(0, 0), to: SIMD2(30, 40))
print(lin.value)  // 50.0
```

--------------------------------

### Example Usage of ShapeFixer

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Shape-Completions.md

Demonstrates initializing a ShapeFixer, setting precision, performing repairs, and checking if a fix was applied.

```swift
let fixer = ShapeFixer(shape: badShape)
fixer.setPrecision(1e-4)
fixer.perform()
if let fixed = fixer.shape { print(fixer.status(2)) } // true = something was fixed
```

--------------------------------

### Edge Endpoints Property

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Edge.md

Get the start and end 3D points (vertices) of the edge. Returns (.zero, .zero) on failure.

```swift
public var endpoints: (start: SIMD3<Double>, end: SIMD3<Double>) { get }
```

```swift
let ep = box.edge(at: 0)!.endpoints
print(ep.start, ep.end)
```

--------------------------------

### Camera.init()

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Display.md

Creates a camera with default settings and a zero-to-one depth range, making its projection matrix directly usable in Metal shaders.

```APIDOC
## Camera.init()

### Description
Creates a camera with default settings and zero-to-one depth range.

### Method
public init()

### Remarks
The underlying `Graphic3d_Camera` is created with `SetZeroToOneDepth(true)` so its projection matrix is directly usable in Metal shaders without remapping.

### OCCT Equivalent
`new Graphic3d_Camera()` + `SetZeroToOneDepth(Standard_True)`

### Example
```swift
let cam = Camera()
cam.eye = SIMD3(0, -100, 50)
cam.center = SIMD3(0, 0, 0)
cam.up = SIMD3(0, 0, 1)
```
```

--------------------------------

### Swift Example: Building a Threaded Rod with a Custom Profile

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/ThreadFeatures.md

This example demonstrates how to create a custom thread profile and use it to build a smooth threaded rod. Ensure the custom profile satisfies `ThreadProfile.supportsSmoothRodBuild` for successful generation.

```swift
guard let tooth = ThreadProfile(vertices: [
    .init(axial: 0.000, depth: 1), .init(axial: 0.125, depth: 1),
    .init(axial: 0.375, depth: 0), .init(axial: 0.625, depth: 0),
    .init(axial: 0.875, depth: 1), .init(axial: 1.000, depth: 1),
  ]),
        let worm = Shape.threadedRod(customProfile: tooth, nominalDiameter: 12,
                                     pitch: 5, cutDepth: 1.8, length: 22) else { return }
// worm.isValidSolid == true — smooth, analytic (handful of B-spline faces)
```

--------------------------------

### Example: Add Profiles at Vertices

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Geometry-Constructors.md

Adds different profiles at the start and end vertices of the spine to define varying cross-sections.

```swift
pipe.add(profile: smallCircle, atVertex: spineStart)
pipe.add(profile: largeCircle, atVertex: spineEnd)
```

--------------------------------

### Get Projection Type

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-XCAF-Notes.md

Retrieves the current projection type of the view object. Example demonstrates setting and then printing the type.

```swift
public var type: ProjectionType { get }
```

```swift
if let view = ViewObject() {
    view.setType(.parallel)
    print(view.type) // parallel
}
```

--------------------------------

### Example Usage of HatchBuilder

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-BSpline-Extrema.md

Demonstrates how to initialize a HatchBuilder, add a vertical line, trim it against a segment, and then print the number of lines and intervals. Requires a valid initialization.

```swift
if let h = HatchBuilder(tolerance: 1e-6) {
    h.addXLine(5.0)
    h.trim(x1: 0, y1: 0, x2: 10, y2: 10)
    print(h.nbLines, h.nbIntervals(lineIndex: 1))
}
```

--------------------------------

### Global Minimization Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Math-Solvers.md

Example demonstrating `globalMinimize` to find the minimum of x² + y² within the bounds [-5, 5] for both variables.

```swift
if let res = MathSolver.globalMinimize(
    variables: 2, lower: [-5, -5], upper: [5, 5]
) { x in x[0]*x[0] + x[1]*x[1] } {
    print(res.minimum)  // ≈ 0
}
```

--------------------------------

### Get Font Path by Index and Aspect

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Display.md

Retrieves the file system path for a font at a given index and style aspect. Returns nil if the font has no file for that aspect or the index is invalid. Example shows getting the path for a bold font.

```swift
if let path = FontManager.fontPath(at: 0, aspect: .bold) {
    print(path)  // e.g. "/System/Library/Fonts/Helvetica-Bold.ttc"
}
```

--------------------------------

### Example: Evaluate Center Point using UV Bounds

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Face.md

Shows how to obtain the UV bounds of a face and then use them to evaluate the 3D point at the center of the UV domain.

```swift
if let uv = face.uvBounds {
    let mid = face.point(atU: (uv.uMin + uv.uMax) / 2,
                           v:   (uv.vMin + uv.vMax) / 2)
}
```

--------------------------------

### Get Interval Bounds

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Shape-HLR-Geom.md

Retrieves the bounds and tolerances of an interval. Returns a Bounds struct containing start, end, tolStart, and tolEnd.

```swift
public var bounds: Bounds { get }
```

--------------------------------

### open()

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

Build (create/truncate) the file and open it for reading and writing. Returns true on success.

```APIDOC
## open()

### Description
Build (create/truncate) the file and open it for reading and writing.

### Method
`open() -> Bool`

### Returns
- `true` on success.

### Request Example
```swift
let f = OSDFile(path: "/tmp/out.txt")
if f.open() { f.write("hello") }
```
```

--------------------------------

### Centermark Example Usage

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/DrawingAnnotation.md

Demonstrates how to create and use a Centermark annotation with custom extent. This example shows the practical application of the Centermark initializer.

```swift
let cm = DrawingAnnotation.centermark(
    DrawingAnnotation.Centermark(centre: SIMD2(50, 50), extent: 10)
)
```

--------------------------------

### Get First Vertex of Edge

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Mesh-Fixing.md

Retrieves the starting vertex point of an edge shape. Returns zero vector if the shape is not an edge.

```swift
public func edgeVertex1() -> SIMD3<Double>
```

--------------------------------

### VisMaterialPBR.init()

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-XCAF-Notes.md

Initializes a PBR material with default OCCT values.

```APIDOC
## VisMaterialPBR.init()

### Description
Create PBR material with OCCT default values.

### Method
`init()`

### Parameters
None

### Response
None

### Example
```swift
public init()
```
```

--------------------------------

### Example: Build Pipe Shell

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Geometry-Constructors.md

Attempts to build the pipe shell and includes error handling for build failures.

```swift
guard pipe.build() else { /* handle failure */ }
```

--------------------------------

### Get Tangent at Abscissa

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/CurveAdaptors.md

Calculates the unit tangent vector at a specified arc length from the start of the edge. Returns nil on failure.

```swift
public func tangent(atAbscissa s: Double) -> SIMD3<Double>?
```

```swift
let ec = EdgeCurve(edge)!
let t = ec.tangent(atAbscissa: 0)  // tangent at the start
```

--------------------------------

### TopologyGraph Snapshot and Restore Round-trip Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/TopologyGraph-Attributes.md

Demonstrates the complete process of creating a graph, setting an attribute, snapshotting it, and then restoring it from the snapshot.

```swift
// Round-trip
guard let graph = TopologyGraph(shape: myShape) else { return }
graph.setAttribute("quality", .string("high"), for: someRef)
let snap = try graph.snapshot()
let data = try GraphSnapshot.canonicalEncoder().encode(snap)

// Later...
let snap2 = try JSONDecoder().decode(GraphSnapshot.self, from: data)
let graph2 = try TopologyGraph(snapshot: snap2)
let quality = graph2.attribute("quality", for: someRef)
// quality == .string("high")
```

--------------------------------

### Example Usage of nextValueOfUV

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Surface-Analysis.md

Illustrates using nextValueOfUV for projecting a sequence of points along a surface, starting with an initial UV guess.

```swift
if let srf = Surface.sphere(radius: 5) {
    var prev = srf.valueOfUV(point: SIMD3(5, 0, 0)).uv
    for pt in samplePoints {
        let p = srf.nextValueOfUV(previousUV: prev, point: pt)
        prev = p.uv
    }
}
```

--------------------------------

### Get Surface Parameter Bounds

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Math-Solvers.md

Retrieves the (u, v) parameter domain of a surface. Example shows accessing bounds and printing them.

```swift
public var parameterBounds: (uMin: Double, uMax: Double, vMin: Double, vMax: Double) { get }
```

```swift
let s = Surface.cylinder(axis: .zero, direction: SIMD3(0,0,1), radius: 5)!
let b = s.parameterBounds
print(b.uMin, b.uMax)  // 0.0, 2π
```

--------------------------------

### Material.init

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Color-Material.md

Creates a PBR material with specified properties. The metallic, roughness, and transparency values are clamped between 0 and 1.

```APIDOC
## Material.init(baseColor:metallic:roughness:emissive:transparency:)

### Description
Creates a PBR material.

### Parameters
- **baseColor** (Color) - albedo color (the primary reflective color).
- **metallic** (Double) - 0.0 = dielectric (plastic/paint), 1.0 = metal (default `0.0`). Clamped to [0, 1].
- **roughness** (Double) - 0.0 = mirror-smooth, 1.0 = fully matte (default `0.5`). Clamped to [0, 1].
- **emissive** (Color?) - optional self-emission color for glowing materials.
- **transparency** (Double) - 0.0 = opaque, 1.0 = fully transparent (default `0.0`). Clamped to [0, 1].

### Example
```swift
let mat = Material(
    baseColor: Color(red: 0.9, green: 0.7, blue: 0.1),
    metallic: 1.0,
    roughness: 0.2
)
```
```

--------------------------------

### Get Font Aspect Name

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Display.md

Retrieves the string representation for a given FontAspect. Example shows how to print the name of the bold aspect.

```swift
print(FontManager.FontAspect.bold.name)   // "Bold"
```

--------------------------------

### IDFilter.init?(ignoreAll:)

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-OCAF-Attributes.md

Initializes an attribute-ID filter to manage GUID inclusion/exclusion for OCAF copy/paste. The filter can start in either a deny-all or allow-all mode.

```APIDOC
## IDFilter.init?(ignoreAll:)

### Description
Create an attribute-ID filter governing which GUID-keyed attributes are included or excluded during OCAF copy/paste operations.

### Parameters
#### Path Parameters
- **ignoreAll** (Bool) - Required - when `true` the filter starts in deny-all mode and only GUIDs explicitly `keep`-ed pass through; when `false` it starts in allow-all mode and only `ignore`-ed GUIDs are excluded.

### Response
#### Success Response (200)
- **IDFilter** (IDFilter) - A configured filter, or `nil` on allocation failure.

### Request Example
```swift
if let f = IDFilter(ignoreAll: true) {
    f.keep("2a96b614-ec8b-11d0-bee7-080009dc3333")
}
```
```

--------------------------------

### Example Usage

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document.md

Demonstrates how to set and retrieve named real and string values on a label.

```APIDOC
## Example

```swift
guard let label = doc.createLabel() else { return }
_ = label.setNamedReal("mass_kg", value: 2.75)
_ = label.setNamedString("material", value: "Aluminium 6061")
print(label.namedReal("mass_kg") ?? 0)        // 2.75
print(label.namedString("material") ?? "")    // Aluminium 6061
```
```

--------------------------------

### Get Root Assembly Nodes

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document.md

Retrieves the top-level nodes in the document's assembly structure. Use this to start traversing the assembly hierarchy.

```swift
public var rootNodes: [AssemblyNode] { get }
```

```swift
func printTree(_ node: AssemblyNode, indent: Int = 0) {
    print(String(repeating: "  ", count: indent) + (node.name ?? "<unnamed>"))
    for child in node.children { printTree(child, indent: indent + 1) }
}
doc.rootNodes.forEach { printTree($0) }
```

--------------------------------

### OSDFile.init()

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

Create a temporary file. The path for the temporary file is chosen by OCCT.

```APIDOC
## OSDFile.init()

### Description
Create a temporary file (path chosen by OCCT).

### Method
`init()`

### Request Example
```swift
let tmp = OSDFile()
```
```

--------------------------------

### WireBuilder.init()

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Mesh-Fixing.md

Initializes an empty wire builder.

```APIDOC
## `WireBuilder.init()`

Create an empty wire builder.

### Method
```swift
public init()
```

### Description
Initializes an empty wire builder. Unlike `Shape.wireFromEdges(_:)`, `WireBuilder` lets you add edges one-by-one and inspect the error state before retrieving the result.

### OCCT
`BRepBuilderAPI_MakeWire()` (via `OCCTWireBuilderCreate`)
```

--------------------------------

### Get Elapsed Time

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

Retrieves the elapsed time in seconds since the timer was started and before it was stopped. This property provides the duration of the measured operation.

```swift
public var elapsed: Double
```

--------------------------------

### Get Curve Start Point

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Curve3D.md

Retrieves the 3D point at the beginning of the curve's parametric domain. This is a convenience for accessing `point(at: domain.lowerBound)`.

```swift
let seg = Curve3D.segment(from: SIMD3(1, 2, 3), to: SIMD3(4, 5, 6))!
print(seg.startPoint)  // SIMD3(1.0, 2.0, 3.0)
```

--------------------------------

### Create Directory

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Geometry-Constructors.md

Creates a directory at the given file-system path. Returns true on success. Use this to prepare output locations.

```swift
DirectoryUtils.create("/tmp/output")
```

--------------------------------

### Get Point at Abscissa

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/CurveAdaptors.md

Calculates the 3D point at a specified arc length from the start of the edge. Returns nil if conversion or evaluation fails.

```swift
public func point(atAbscissa s: Double) -> SIMD3<Double>?
```

```swift
let ec = EdgeCurve(edge)!
let half = ec.point(atAbscissa: ec.length / 2)
```

--------------------------------

### Example: Get Z-Levels of Box Faces

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Face.md

Demonstrates how to extract the Z-levels from all faces of a box shape. Useful for identifying top and bottom faces.

```swift
let box = Shape.box(width: 10, height: 10, depth: 5)!
let zLevels = box.faces().compactMap { $0.zLevel }
// zLevels contains 0.0 (bottom) and 5.0 (top)
```

--------------------------------

### Example: Create and Build a Filleted Box

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Builders-Fillet.md

This example demonstrates initializing a FilletBuilder with a box shape, adding all its edges with a constant radius, and then building the filleted shape.

```swift
guard let box = Shape.box(width: 20, height: 20, depth: 20),
      let builder = FilletBuilder(shape: box) else { return }
for edge in box.edges() {
    _ = builder.addEdge(edge, radius: 2.0)
}
if let filleted = builder.build() {
    print("filleted shape valid:", filleted.isValid)
}
```

--------------------------------

### Get View Name

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-XCAF-Notes.md

Retrieves the display name of the view. Returns nil if no name has been set. Example shows setting and then printing the name.

```swift
public var name: String? { get }
```

```swift
if let view = ViewObject() {
    view.setName("Front")
    print(view.name ?? "") // "Front"
}
```

--------------------------------

### Sheet Standard Layout Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/SheetMetal.md

Demonstrates how to create a standard layout for a shape, render it into a DXF writer, and save it to a file. Ensure the shape projection is successful.

```swift
let sheet = Sheet(size: .a3, projection: .first)
let box = Shape.box(width: 80, height: 50, depth: 30)!
if let layout = sheet.standardLayout(of: box, scale: .oneToTwo, margin: 15) {
    let writer = DXFWriter()
    layout.render(into: writer)
    try writer.dxfString().write(toFile: "/tmp/bracket.dxf",
                                 atomically: true, encoding: .utf8)
}
```

--------------------------------

### Load, Inspect, and Export Assemblies

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/guides/cookbook/xcaf-assemblies.md

Demonstrates loading a STEP assembly, inspecting its root nodes for names and colors, and exporting it back as a structured STEP file or a GLTF/GLB model.

```swift
// load a STEP assembly — structure, names, colors preserved
let doc = try Document.load(from: stepURL)
for root in doc.rootNodes {
    print(root.name ?? "—", root.color as Any)
}

// write it back out, structure intact
try Exporter.writeSTEPAssembly(doc, to: outURL)   // product-structured STEP
try doc.write(to: outURL)                          // same (STEP)
doc.writeGLTF(to: glbURL, binary: true)            // GLB for the web (returns Bool)
```

--------------------------------

### Get Contour Points

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Shape-Features.md

Retrieves the starting vertices of all edges in the shape, suitable for simple polygon contours. For curved edges, use `edgePoints(at:maxPoints:)`.

```swift
public func contourPoints(maxPoints: Int = 1000) -> [SIMD3<Double>]
```

--------------------------------

### Get 3D Position of Edge's First Vertex

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Geometry-Constructors.md

Retrieves the 3D coordinates of the starting vertex of an edge. Useful for geometric calculations and positioning.

```swift
public static func firstVertex(_ edge: Shape) -> SIMD3<Double>
```

```swift
let start = EdgeAnalysis.firstVertex(myEdge)
```

--------------------------------

### Example: Printing All Layer Names

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document.md

Demonstrates how to retrieve and print all layer names from a document, separated by commas.

```swift
print("Layers:", doc.layerNames.joined(separator: ", "))
```

--------------------------------

### Example Usage: Creating and Measuring a 2D Circle

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

Demonstrates how to create a 2D circle using the center and radius factory method and then calculate its length. Ensure the circle is successfully created before attempting to measure it.

```swift
if let c = Curve2D.gceCircle(center: SIMD2(0, 0), radius: 5) {
    print(c.length())
}
```

--------------------------------

### Get Native Parameter at Abscissa

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/CurveAdaptors.md

Finds the native parameter corresponding to a given arc length from the start of the edge. Returns nil if the solver does not converge.

```swift
public func parameter(atAbscissa s: Double) -> Double?
```

```swift
let ec = EdgeCurve(edge)!
if let u = ec.parameter(atAbscissa: ec.length / 2) {
    print(u)
}
```

--------------------------------

### Example Usage of Extrude Initializer

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/FeatureReconstructor.md

Demonstrates how to create an Extrude feature specification using a square profile, a plane at the origin with a Z-normal, and a specified length.

```swift
let pts: [SIMD2<Double>] = [.init(-5, -5), .init(5, -5), .init(5, 5), .init(-5, 5)]
  let ext = FeatureSpec.Extrude(
      profilePoints2D: pts,
      planeOrigin: .zero,
      planeNormal: SIMD3(0, 0, 1),
      length: 20,
      id: "block")
```

--------------------------------

### Example: Analyzing Shape Contents

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Mesh-Fixing.md

Demonstrates how to get extended shape contents for a box shape and print the counts of faces, edges, and B-spline surfaces.

```swift
let box = Shape.box(width: 10, height: 10, depth: 10)!
let c = box.contentsExtended()
print("faces:", c.nbFaces, "edges:", c.nbEdges)
print("B-spline surfaces:", c.nbBSplineSurf)
```

--------------------------------

### PerfMeter.start()

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

Starts the performance timer.

```APIDOC
## PerfMeter.start()

### Description
Start the performance timer.

### Method
POST

### Endpoint
/OSD_Host/PerfMeter/start
```

--------------------------------

### Get OSDFile Size

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

Retrieves the size of the file in bytes. Returns nil if the file size cannot be determined, for example, if the file is not open or an error occurs.

```swift
public var fileSize: Int?
```

--------------------------------

### Example: Load Document and Access GD&T Data

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document.md

Demonstrates loading a STEP file into a `Document` object and accessing counts and names of dimensions, tolerances, and datums.

```swift
let doc = try Document.load(from: gdt_step_url)
print("Dimensions:", doc.dimensions.count)
print("Tolerances:", doc.geomTolerances.count)
for datum in doc.datums { print("Datum:", datum.name) }
```

--------------------------------

### Example: Get Normal at UV Minima

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Face.md

Demonstrates retrieving the surface normal at the minimum U and V parameters of a face's UV bounds and printing it.

```swift
if let uv = face.uvBounds, let n = face.normal(atU: uv.uMin, v: uv.vMin) {
    print(n)
}
```

--------------------------------

### Get Unit Tangent at Arc Length

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/CurveAdaptors.md

Retrieves the unit tangent vector at a specific arc length from the start of the wire. Returns nil if conversion or evaluation fails.

```swift
public func tangent(atAbscissa s: Double) -> SIMD3<Double>?
```

```swift
let wc = WireCurve(wire)!
let quarterTangent = wc.tangent(atAbscissa: wc.length / 4)
```

--------------------------------

### Example Usage of SewingBuilder

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-BSpline-Extrema.md

Demonstrates how to initialize SewingBuilder, add shapes, perform the sewing operation, and check the result. This is useful for creating a single shell from multiple input shells.

```swift
if let sew = SewingBuilder(tolerance: 1e-5) {
    sew.add(shell1)
    sew.add(shell2)
    sew.perform()
    if let sewn = sew.result {
        // sewn shell
    }
}
```

--------------------------------

### BREP Serialization Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Transforms.md

Demonstrates serializing a box shape to BREP format and then deserializing it back into a shape.

```swift
if let box = Shape.box(width: 5, height: 5, depth: 5),
   let brep = box.toBREPString(),
   let restored = Shape.fromBREPString(brep) {
    // restored is equivalent to box
}
```

--------------------------------

### Example Usage of Shape.section2D

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Construction.md

Demonstrates how to use the section2D method to get a 2D contour of a box shape. The resulting drawing's visible edges contain the contour.

```swift
let box = Shape.box(width: 50, height: 50, depth: 50)!
if let drawing = box.section2D(planeOrigin: SIMD3(0, 0, 25),
                                  planeNormal: SIMD3(0, 0, 1)) {
    // drawing.visibleEdges contains the 50×50 square contour at Z=25
    let dxf = Exporter.exportDXF(drawing: drawing)
}
```

--------------------------------

### Initialize OSDFile with a Path

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

Create an OSDFile instance for a given file system path. This is useful for working with existing files or creating new ones at a specified location.

```swift
public init(path: String)
```

```swift
let f = OSDFile(path: "/tmp/output.txt")
```

--------------------------------

### Get 3D Point at Arc Length on WireCurve

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/CurveAdaptors.md

Calculates the 3D point at a specific arc length 's' from the start of the wire. Returns nil if conversion or evaluation fails.

```swift
let wc = WireCurve(Wire.rectangle(width: 40, height: 20)!)!
let mid = wc.point(atAbscissa: wc.length / 2)
```

--------------------------------

### Example: Measure Operation Time

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

Demonstrates the usage of PerfMeter to measure the duration of an operation. It involves creating a meter, starting it, performing work, stopping it, and then printing the elapsed time.

```swift
let meter = PerfMeter(name: "myOp")
meter.start()
// ... work ...
meter.stop()
print(meter.elapsed)
```

--------------------------------

### Sheet Render BOM Example

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Selection.md

Demonstrates rendering a Bill of Materials onto a DXF sheet using default settings.

```swift
var writer = DXFWriter()
let sheet = Sheet(size: .a3, orientation: .landscape)
sheet.render(into: &writer)
sheet.renderBOM(bom, into: writer)
```

--------------------------------

### FaceFixer.init(face:precision:)

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Mesh-Fixing.md

Initializes a face fixer with a given face and precision.

```APIDOC
## FaceFixer.init(face:precision:)

### Description
Initializes a face fixer with the given face and precision.

### Method
`public init?(face: Shape, precision: Double = 1e-6)`

### OCCT
`ShapeFix_Face` (via `OCCTFaceFixerCreate`)
```

--------------------------------

### Get Edges Adjacent to a Vertex

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Analysis-Builders.md

Retrieves the 1-based indices of edges that are adjacent to a specific vertex within the shape. The indices are up to 64. An example shows how to interpret the result of edgeFaceAdjacency.

```swift
public func adjacentEdges(forVertex vertex: Shape) -> [Int]
```

```swift
let faceCounts = box.edgeFaceAdjacency()
// faceCounts[i] == 2 for interior edges shared by two faces
```

--------------------------------

### Example: Creating and Using PolygonOnTriangulation with Parameters

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Shape-Recognition.md

Demonstrates creating a PolygonOnTriangulation with node indices and parameters, then accessing its node count.

```swift
if let poly = PolygonOnTriangulation.create(nodeIndices: [0, 5, 12],
                                               parameters: [0, 0.5, 1]) {
    print(poly.nodeCount)  // 3
}
```

--------------------------------

### Get All Font Names

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Display.md

Retrieves an array of all available system font family names. Skips fonts whose names cannot be decoded. Example shows checking for the presence of 'Helvetica'.

```swift
FontManager.initDatabase()
let names = FontManager.allFontNames
let hasHelvetica = names.contains("Helvetica")
```

--------------------------------

### Get Curve Parameter at Arc Length

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Curve2D.md

Calculates the curve parameter corresponding to a specific arc-length distance from a starting parameter. Useful for trimming curves or positioning features along their length.

```swift
public func parameterAtLength(_ arcLength: Double, from fromParameter: Double? = nil) -> Double?
```

```swift
let seg = Curve2D.segment(from: .zero, to: SIMD2(10, 0))!
if let u = seg.parameterAtLength(5) {
    let pt = seg.point(at: u)  // ≈ SIMD2(5, 0)
}
```

--------------------------------

### GraphSnapshot.init(brep:attributes:formatVersion:)

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/TopologyGraph-Attributes.md

Creates a GraphSnapshot directly from its components.

```APIDOC
## GraphSnapshot.init(brep:attributes:formatVersion:)

### Description
Create a snapshot directly.

### Method
`init(brep: String, attributes: NodeAttributeStore, formatVersion: Int = GraphSnapshot.currentFormatVersion)`

### Parameters
#### Path Parameters
- **brep** (String) - BREP string of the source shape.
- **attributes** (NodeAttributeStore) - the attribute store.
- **formatVersion** (Int) - defaults to `currentFormatVersion`.
```

--------------------------------

### Example: Free Bounds Analysis

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Document-Mesh-Fixing.md

Demonstrates how to perform free bounds analysis on a shape and print the counts of open and closed free bounds.

```swift
let shell = Shape.box(width: 10, height: 10, depth: 10)!  // closed — 0 free bounds
if let fp = FreeBoundsProperties(shape: shell) {
    _ = fp.perform()
    print("closed:", fp.closedCount, "open:", fp.openCount)
}
```

--------------------------------

### Get Font Name by Index

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Display.md

Retrieves the font family name at a specific 0-based index. Returns nil if the index is out of range. Example shows iterating and printing all font names.

```swift
FontManager.initDatabase()
for i in 0..<FontManager.fontCount {
    if let name = FontManager.fontName(at: i) {
        print(name)
    }
}
```

--------------------------------

### Get Interval Bounds by Index

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Shape-HLR-Geom.md

Retrieves the start and end bounds of an interval at a specific zero-based index within the set. Note that the index is internally mapped to OCCT's 1-based indexing.

```swift
public func bounds(at index: Int) -> Interval.Bounds
```

--------------------------------

### Example: Projecting a World Point

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Display.md

Demonstrates how to use the `project` method to convert a world-space point to normalized device coordinates.

```swift
let ndc = cam.project(SIMD3(10, 0, 0))
```

--------------------------------

### Check if Font Has Aspect

Source: https://github.com/secondmouseau/occtswift/blob/main/docs/reference/Display.md

Tests if a font at a given index supports a specific style aspect. Returns true if a file exists for that aspect. Example shows checking for bold italic and then getting its path.

```swift
if FontManager.fontHasAspect(at: 0, aspect: .boldItalic) {
    let path = FontManager.fontPath(at: 0, aspect: .boldItalic)
}
```