The Curious Case of Splines in FreeCAD (lgm2025)

Splines, especially in their general form as NURBS, are an extremely versatile tool in a 3D designer's kit. They allow the designer to succinctly and efficiently model objects of arbitrary shape and smoothness. For converting these designs into physical objects, FreeCAD has a vast set of tools to operate on NURBS, both as planar curves and (with addons) as surfaces. However, the complications of NURBS can also cause a good amount of confusion, especially compared to other representations of splines, which may be more familiar to the user from other applications (which may include other CAE apps as well as more artistic tools like Inkscape). In this talk, I discuss some of these common questions often seen in the issue tracker and forums, as well as best practices to follow for common workflows. I also showcase current progress and future plans to make the experience more intuitive and in line with other apps. Licensed to the public under https://creativecommons.org/licenses/by/4.0/ about this event: https://pretalx.c3voc.de/lgm25-upstream-2025/talk/3097564238/