I use openSCAD for all of my 3D printing. It is some seriously whacky shit to write. There are a lot of quirks that are best learned by doing. Still, it's powerful enough to make some complicated objects.

NURBS usually requires relatively specialized libraries[0], which don't exist (at high enough quality) in the open source community.

[0] Mostly due to precision issue with floating point representations.

> NURBS usually requires relatively specialized libraries[0], which don't exist (at high enough quality) in the open source community.

There is fully opensource cross-platform NURBS modeler — Ayam[0], but it looks not NOT user friendly (as for me).

Also there is FreeShip Plus[1] which is truly NURBS 3D CAD.

[0] http://ayam.sourceforge.net/

[1] https://github.com/markmal/freeship-plus-in-lazarus

Maybe libfive?

> all the Linux tools and open source ones seem to be focussing on mesh modelling

There is some support for NURBS in Blender (3DView->Add->Surface->NURBS Surface) , but it is indeed minimal.

> What I miss the most is a good NURBS modelling that is runs on Linux

Try FreeShip Plus (Lazarus port of FREE!Ship+).[0]

Also, check Paolo Furani's technique on SubD modeling in Blender and converting to NURBS via FreeShip.[1,2]

[0] https://github.com/markmal/freeship-plus-in-lazarus

[1] https://twitter.com/PaoloFurani/status/1407071700244701195

[2] https://blenderartists.org/t/from-blender-subdivision-to-n-u...

Solvespace might be of interest you if you haven't heard of it!

Solvespace is a CAD tool that makes heavy use of constrains and uses the traditional CAD way of building 3D models, where most of the work happens in 2D planes then gets "lifted" to 3D.

It's useful when you build 3D objects that have to obey strict engineering constraints.

3D modeling for games / sfx / 3Ddesign rarely has such problem and typically follows a very different workflow.

I don't think SolveSpace is in that niche at all, it's for parametric design, like FreeCAD.

Have you tried it. Way different than freecad. You set constraint of equality or whatever. You leave it open ended and now you can add those same constraints in the 3D and transform your shape in this hybrid feel, that feels like your are modelling an equation with your hand.

That being said Freecad is way more versatile and you can do almost anything. Solve space is more like the equivalent of building a freecad model out of clay. You can always adjust it but you don’t end up with anything more usable than a stl file in reality, which you can then import into freecad lol.

Openscad and opencascade are for CAD program designers imho . Although version control is so appealing.

I love OpenSCAD for specific tasks like modeling microcontrollers against vendor datasheets. While this is not often required with commercial tools and conventional component suppliers, KiCad + chipageddon + being based in China means I've done quite a bit of that recently and it's been largely efficient, cross-platform and up to task. I am competent with Blender, but prefer OpenSCAD for this domain. Haven't really looked in to SolveSpace.

I have tried it, yes. You can add constraints to any parametric CAD software, like FreeCAD, OnShape, Solidworks, Fusion, etc.

> You can add constraints to any parametric CAD software, like FreeCAD,...

SolveSpace has a little bit different constraints solver.

There is Assembly3 worbench for FreeCAD, which is based on SolveSpace solver.[0]

[0] https://github.com/realthunder/FreeCAD_assembly3/wiki/Constr...

Hmm, it's been a while since I last tried it, but I remember the constraints being pretty much the same as other software. Maybe I should try again.

It's just a different implementation of exactly the same idea. I've used every parametric CAD software that exists (more or less) and their sketch constraint solvers are generally indistinguishable. They only differ in small details - can you select the midpoint of a line? can you have mirror constraints? are they vaguely stable when underconstrained? etc.

> I don't think SolveSpace is in that niche at all

SolveSpace could export designed 3D model as NURBS geometry to STEP (.stp), but there are no advanced tools for NURBS surface modeling.

libfive is a new CAD kernel based on functional-representation. It seems like a good library to use to make something like that, if anyone is interested.