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OCCTSwiftMesh

Mesh+Simplify

The decimation entry point. OCCTSwiftMesh extends OCCTSwift.Mesh with simplified(_:), a quadric-error-metric (QEM) edge-collapse decimator backed by the vendored meshoptimizer. It takes a SimplifyOptions and returns a SimplifiedMesh — the reduced mesh plus the achieved Hausdorff distance — or nil on invalid input. See the decimation algorithm notes for the backend semantics.

Topics

simplified(_:)

Decimate this mesh using a quadric-error-metric edge-collapse algorithm. Orphan vertices left behind by collapsed edges are compacted, so the output mesh’s vertexCount is exactly the count of vertices still referenced by a surviving triangle.

public func simplified(_ options: Mesh.SimplifyOptions) -> SimplifiedMesh?
  • Parameters:
    • options — a Mesh.SimplifyOptions carrying the target count or reduction ratio (exactly one), plus optional boundary / topology / Hausdorff constraints.
  • Returns: a SimplifiedMesh carrying the decimated mesh and the achieved Hausdorff distance, or nil if the options are invalid (neither or both targets set, a targetTriangleCount outside [1, input.triangleCount], a targetReduction outside [0, 1], or a negative maxHausdorffDistance) or the input mesh is empty.
  • Example: 
    import OCCTSwift
import OCCTSwiftMesh

let mesh: Mesh = shape.mesh()

var options = Mesh.SimplifyOptions(targetReduction: 0.5)
options.preserveBoundary = true
options.maxHausdorffDistance = 0.05

guard let result = mesh.simplified(options) else { return }
print("\(result.beforeTriangleCount) → \(result.afterTriangleCount) triangles")
print("Hausdorff error: \(result.hausdorffDistance)")
let reduced: Mesh = result.mesh