Building Part3D, an iPad-first CAD app for makers, hobbyists, and 3D printing enthusiasts. It combines parametric 2D sketching with solid modeling features like extrude, fillets, chamfers, and direct integration with slicers, aiming to make CAD more accessible without sacrificing capability. Learning a lot about geometric kernels, constraint solvers, and the trade-offs between OpenCASCADE and Parasolid. Also diving into Rust and C . Based in Brazil 🇧🇷, but always happy to connect with other builders working on hard technical problems.

I’ve done lots of OpenSCAD. There are also Python libraries that use OpenCASCADE for something similar. @grok, care you research this?

Oh...something like OpenCascade (OCCT)? I'm wondering if they can be used with Freestyle or LineArt or whether they need to be converted to Mesh?

Impressed by what you’ve built. Almost signed up the other day but paused because of a couple of blind spots. what’s the underlying kernel (opencascade?) and why does a prompt in cadX give better results than a prompt in codex (what’s additional under the hood)?

Use CAD software. If you are working on some specific parts repeatedly, you could parametrise them or even automate their creation if you can work with kernels like OpenCASCADE or openSCAD. It gives you more control and automation power, without losing any information.

Yeah becuase opencascade fucking sucks

you'll get better results using openscad for simple parts like the above build123d / opencascade is a complete cad kernel so better for more complex stuff

thoughts on opencascade? every open source kernel seems kinda cooked.

After probably 100 hours I can finally say I am coming to a stop. Shout out to @Replit . This started for their 10 year anniversary buildathon and I haven't stopped since. Long days, sometimes 16 hour days at the weekend. I'm at a stage where I can finally sign off. KinetiCAD is browser-native parametric CAD. Real B-rep geometry kernel, OpenCascade compiled to WebAssembly. Live rigid-body physics with Rapier. Sketch, extrude, revolve, fillet, chamfer, boolean operations. Five mate types, motorised joints. An eight-material library with density-driven mass. STEP import, export and round-trip. WebGPU rendering. No install, no licence, no CAD seat. Verified by maths, not vibes: A motorised windmill assembly tuned to hold exactly pi radians per second. Across 420 simulation steps it held between 3.1415925 and 3.1415930. Target pi is 3.1415927. Every sample within 1.5e-7. Material mass is real arithmetic, not an estimate. A 5.70 cm³ part: steel at 7.87 g/cm³ gives 0.045 kg, brass at 8.50 gives 0.048 kg, PLA at 1.25 gives 0.007 kg. Exact, every time. If the maths is wrong, it is not a CAD tool. So the maths gets checked. FREE to use and open source. MIT licensed. I will always try something, even if I fail, because that's my mindset. kineticad.co.uk/ @ThreeJS #CAD #BuildInPublic #AdeviousAI

1/ I have just updated KinetiCAD: parametric CAD running entirely in a browser tab. Two engines in parallel Web Workers, a real B-rep kernel and a live physics engine. Full breakdown below. 2/ Geometry: OpenCascade, a real solid modelling kernel, compiled to WebAssembly. Sketching, Extrude, Revolve, Fillet, Chamfer, Hole, and Boolean operations (Union, Subtract, Intersect). Multi-part assemblies with a transform gizmo. 3/ Mates and physics: five mate types (Revolute, Prismatic, Spherical, Fixed, Planar), motors on revolute and prismatic joints. Rapier physics in a second worker turns the mates into real constraints and drives them. 4/ File interop: STL export, STEP import and export with full round-trip, plus native Save and Load of a whole assembly as JSON. STEP tested on real McMaster-Carr industrial parts. STL verified by slicing to a complete print plan in Bambu Studio. 5/ Proof it works: an orrery. 13 bodies, 12 motorised revolute joints in nested chains. Every build is regression-tested against a canary joint that must hold pi rad/s to within 5e-7. 6/ Before going public: a full audit. Secrets scan, static analysis, dependency check, no internal files leaking. All clean. WebGPU-only, built for modern hardware by design. Phases 0-9 of 12 done. Open source, MIT, live now: kineticad.replit.app/ github.com/AndrewBlumson/Kin… #BuildInPublic #CAD #AdeviousAI @threejs

Literally just make a new cheap geometry kernel. Or make OpenCASCADE better.

A new version of Open Cascade Technology 8.0 has been released. This geometric kernel forms the backbone of several projects such as #FreeCAD, #IfcOpenShell, or #KiCAD. The release announcement is here: occt3d.com/occt3d-open-sourc… #OpenCascade #OCCT3D #OCCT #OpenSource

💡 𝗢𝗽𝗲𝗻 𝗖𝗔𝗦𝗖𝗔𝗗𝗘 𝗧𝗲𝗰𝗵𝗻𝗼𝗹𝗼𝗴𝘆 𝟴.𝟬.𝟬 𝗶𝘀 𝗻𝗼𝘄 𝗮𝘃𝗮𝗶𝗹𝗮𝗯𝗹𝗲! Full release notes and discussion: github.com/Open-Cascade-SAS/… #OpenCASCADE #OCCT #OCCT3D #3DModeling #CAD #CAE #OpenSource #3D #Release

今の自作CADの方向性のひとつとして、 「OpenCascade」なるものを利用する形にするのどうかなって相談したら、 「メッシュ → B-rep変換が鬼難しい！」 っていわれた。 鬼難しいとかいわれたら、さすがに手が出せんな。（笑）

コードでモデリングといえばOpenSCADだろ、位の気持ちで試してたけど、現代はCadQueryなるものがあってそちらのほうが優位そうであった。OpenCASCADEだからFreeCADとの互換性もよい。これでもう一度試してみようかな

We presented FreeCAD to the established manufacturing industry in Germany at Hannover Messe. While Matas from @bitbybit_dev showcased his product configurator, based on OpenCascade, I presented a fully open-source workflow for product development, including FreeCAD.

Dear CAD community, I am looking for suggestions on efficient approaches for computing distances to the boundaries of CAD parts. I am currently using .step files with the openCascade. But , this is slow. Appreciate suggestions for other ways of doing this more effectively.

Kicadとかの電子回路系もopenCASCADEなんてすね。ビビった。CADカーネル必要なんだ

CADカーネルから見るこのCAD業界図はやっぱり面白くて、どのCADソフトがどの会社に首根っこが掴まれてるのかが分かりますし、無料CAD勢がほぼすべてOpenCascade依存なのも良くわかります cadmap.io/

all the big CAD programs have decent APIs. Fusion, Onshape, FreeCAD are all scriptable to varying degrees. If you want pure code-CAD, try Zoo or Build123D. If you want to roll your own, use OpenCascade!