Does this use its own backend/engine? I've been working on LLM to CAD tool[0] an...

ur-whale · 2026-03-31T14:47:02 1774968422

> I think OpenSCAD is currently the best and most feature complete choice

As much as I love OpenSCAD, I would strongly disagree with your conclusion.

All the OpenSCAD language can do is boolean operations and moreover, the engine can only implement those on polygonal (triangle actually) meshes.

That's a very far cry from what a modern commercial CAD engine can do.

For example, the following things are very, very hard to do, or even specify using OpenScad:

   - Smooth surfaces, especially spline-based

   - Fillets / Chamfers between two arbitrary surfaces

   - Trimming surfaces

   - Querying partly built models and using the outcome in the subsequent construction (e.g. find the shortest segment between two smooth surfaces, building a cylinder around it and filleting it with the two surfaces, this is an effing nightmare to do within the confines of OpenSCAD)

   - Last but not least: there is no native constraint solver in OpenSCAD, neither in the language nor in the engine (unlike - say - SolveSpace)

I might have misunderstood what you're looking to do, but, yeah, digging deeper feels very much like the right thing to do.

FeepingCreature · 2026-03-31T15:34:25 1774971265

(my) fncad doesn't have the querying, but it does have smooth csg! https://fncad.github.io/

Zekio · 2026-03-31T15:46:09 1774971969

using BOSL2 alleviates most issues I've run into with OpenScad for chamfers and the like, but it is an extra set of functions you need to remember sadly

https://github.com/BelfrySCAD/BOSL2

ur-whale · 2026-03-31T17:11:12 1774977072

> BOSL2 ... but it is an extra set of functions you need to remember sadly

It's also extremely slow: it implements chamfers and fillets using morpho, and if you have a large number of fillets, the morpho algorithms (minkowski / hull) are very much non linear in time on polygonal meshes, which leads to compute time explosion if you want a visually smooth result.

Zekio · 2026-03-31T17:41:38 1774978898

you can get around this somewhat by having less visually smooth previews when editing and higher quality when you want an stl

  $fn = $preview ? 32 : 256;

markcheno · 2026-03-31T16:57:13 1774976233

I just ran into this today: https://github.com/gumyr/build123d - seems like an LLM should have no problem writing python code...

WillAdams · 2026-04-01T00:22:10 1775002930

Recent discussion here:

https://news.ycombinator.com/item?id=47567242

IshKebab · 2026-03-31T15:18:24 1774970304

Yeah it does. In fact I believe it was written to demonstrate improved sketch constraint solving (there's a 2D version too).

Unfortunately aside from the better sketching the engine is not as capable as OpenCascade.

yangcheng · 2026-03-31T14:46:29 1774968389

I have tried OpenSCAD, it seems very slow to compile to display on web. are you using the official wasm or some other ways?

mikeayles · 2026-03-31T15:07:55 1774969675

you may find this useful: https://phaestus.app/blog/blog0031

Edit: Forgot I also got doom running in openscad: https://www.mikeayles.com/blog/openscad-doom/

and doom running in openscad in the browser at https://doom.mikeayles.com/

yangcheng · 2026-04-09T07:37:06 1775720226

cool! it's way faster on desktop. I also recompiled to include 3MF support. However on mobile phones compile is still slow even if I set fa to be lower.

ponyous · 2026-03-31T16:29:14 1774974554

I export it as .3mf file and display it with threejs on the web. Compilation seemed fast enough - few seconds tops.