BasAutomation.Geometry

A small, dependency-free 2D/3D computational geometry library for .NET.

It provides the plain-managed geometry primitives — no CAD kernel, no COM, no native dependencies — that sit underneath the BasAutomation Inventor add-ins and the transient-BRep beam blog series.

Install

dotnet add package BasAutomation.Geometry

What's in it

• Core — Point2D / Point3D, Vector2D / Vector3D, Matrix2D / Matrix3D, Plane3D, Box2D / Box3D, OrientedBox3D, Rectangle2D, miter-plane math
• Curves — Line2D / Line3D, Arc2D / Arc3D, Circle2D / Circle3D, Ellipse2D / Ellipse3D, behind ICurve2D / ICurve3D, plus Path3D, contour offsetting, and curve ordering/intersection helpers
• Surfaces — swept-surface construction from profile curves: cylinder, cone and torus sweeps, a line-sweep classifier (radial/tangential/tilted), and an exact rational B-spline sweep for elliptical profiles
• Coordinate systems — CoordinateSystem2D / CoordinateSystem3D transforms, face-aligned frames, rigid-motion fitting, orientation following
• Ray casting — Ray3D and intersection utilities
• Validation — cross-section validation with structured issues

Everything targets net8.0 and has zero package dependencies.

Example

using BasAutomation.Geometry;

var start = new Point3D(0, 0, 0);
var end   = new Point3D(10, 0, 0);

var dir = (end - start).Normalized();       // Vector3D
var arc = new Arc3D(/* centre, normal, radius, angles */);

bool ccw = arc.IsCounterClockwise;

Note for CAD interop

This library is intentionally CAD-kernel independent. When you use it to drive Autodesk Inventor's TransientGeometry / TransientBRep API, you convert these managed primitives into Inventor's COM types at the boundary (a thin Point3D → Inventor.Point style bridge — shown in the blog series). The library itself has no Inventor reference, so it stays usable in tests, services, and non-CAD contexts.

Building

dotnet build
dotnet test

About this repository

This repository is a read-only public mirror, published automatically when a new package version is released. Development happens in a private monorepo, so the commit history here is one commit per release. Issues are welcome; for pull requests, please open an issue first so the change can be applied upstream.

License

MIT © Bas Nederveen — Bas Automation Services