1. Opennurbs: What is openNURBS?
The openNURBS Toolkit reads and writes all Rhino 3DM files. Additionally, the openNURBS Toolkit provides NURBS evaluation tools and elementary geometric and 3D view manipulation tools.
2. OpenCascade : opencascade
3. CGAL: CGAL
The library offers data structures and algorithms like triangulations, Voronoi diagrams, Boolean operations on polygons and polyhedra, point set processing, arrangements of curves, surface and volume mesh generation, geometry processing, alpha shapes, convex hull algorithms, shape reconstruction, AABB and KD trees…
4. Verb-Nurbs: What is verb?
verb provides advanced tools like derivative evaluation, adaptive tessellation, and intersection. Verb provides a concurrent execution runtime via WebWorkers in modern browsers and thread pools on other platforms and is suitable for use in a datacenter or in the browser.
verb is not a graphics library. It nicely compliments web graphics libraries like three.js, but is happy to live without one.
5. BRL-CAD: BRL‑CAD
Hybrid CSG and B-REP kernel with innovative methods for unambiguous 3D geometry. Verification, validation, performant.
7. GoTools: GoTools
GoTools is the name of a collection of C++ libraries related to geometry. The libraries are organized as a core module with additional modules added on top. The core module contains generic tools and spline functionality. The additional modules contain functionality for intersections, approximative implicitization, parametrization, topology, and more.
SISL is a comprehensive NURBS library for the modeling and interrogation of curves and surfaces. It is implemented in C and has been under continuous development over two decades.
10. Clipper: Clipper
an open source freeware library forclipping and offsetting lines and polygons
A Two-Dimensional Quality Mesh Generator and Delaunay Triangulator.
12. Libtess2: LibTess
13. EarCut: EarCut