Proposal: GUI-first, text-based mechanical CAD inspired by software engineering
2 thinkmachyx 3 7/5/2025, 6:37:00 PM
Most mechanical CAD tools (SolidWorks, Fusion, FreeCAD) still lock all modeling into opaque binary files. That makes it hard to track changes, collaborate with Git, or automate builds.
I’ve written a proposal for an alternative paradigm:
- GUI-first, like KiCad - visual modeling is the default
- Text-based source files (YAML/JSON) — readable, diffable, Git-friendly
- Separation of source and result - .step, .stl and previews are built artifacts
- Parametric logic is explicit - slot width = tab width + clearance
Works with Git, CI, or scripting — no more PDM lock-in The proposal is called SplitCAD, and it's just a concept for now — not a working tool. But I’d love to hear from anyone frustrated by the limitations of current mechanical CAD.
GitHub: https://github.com/yuanxun-yx/SplitCAD
But I am just going to put this here so the general thoughts incorporate a fundamental problem before significant labor investments go too far:
What is a probable, viable, possible answer to the geometry kernel problem?
Parasolid, arguably the leader and generally most capable geometry kernel we have today, is or at least I can't see past...
...is just not something easily duplicated.
There are a bazillion man months of time in that body of code. And those are hard hours!
For those unfamiliar, the geometry kernel is the piece that resolves geometry cases to make operations possible. Imagine a cylinder and rectangle. Now imagine they have some common volume. They intersect, in other words.
Put a fillet on one edge to blend the edge.
How many literal edge and corner cases can you come up with?
There are way more than you think!
Now multiply that tiny problem space with all the geometry used every day.
And then multiple that time again by what it takes to make it robust.
And the whole thing, as it stand today is not even multi-threaded!
Any CAD that we expect to see even moderate general use in a professional sense, needs this piece.
How do we, meaning anyone interested in CAD this way, get past this?
I wish there were some OSS type license for Parasolid. It could be treated like the Linux kernel.
Whatever replaces Parasolid and friends, should be treated like the Linux kernel.
The closest we have is Open Cascade.
Sorry. I do not want to piss on a good vision. But this has to be said.
Peace and good luck!
I used voice input on this. Pleqse forgive typos.
Although building such engine requires tons of work, but the engine we’re having is indeed a bit of old. Except for the problems I mentioned, you also mentioned they’re still single threaded. That’s why I think it’s still worth building a new one, especially when there’s no good open sourced one currently.
I’m a big supporter of open source. If we have something like that in the future, we should of course make it open source like Linux kernel and allow everyone to enjoy the benefit of it.