BTW: I spent a few weekends playing with Microcad (https://microcad.xyz/). It was cool, and had a similar rust feel. I just, for the life of me, couldn't figure out how to do 3d ellipses.
> I keep designing physical parts for our robots. Motor mounts, sensor brackets, wheel hubs. Every time, the workflow is the same: open a GUI CAD program, click around for an hour, export an STL, realize the bolt pattern is 2mm off, repeat.
This doesn't make sense. When you realize the bolt pattern is 2mm off, you just edit that dimension and let the CAD program recalculate. You don't need to click around for an hour again. That's the beauty of contstraint-based parametric modeling as opposed to, say, modeling in Blender.
The author's program is akin to writing vim to replace Publisher. They're solving entirely different problems. Not to mention, this code-as-model paradigm already exists: OpenSCAD
I was thinking the same thing. This looks more like an API that makes 3d modeling look closer to CAD, but without realizing that CAD is about constraints, parametrizing, and far more.
> One thing I care about that most CAD tools don't: vcad is designed to be used by AI coding agents.
But don't actually delete it. It looks like a nice alternative to OpenSCAD. But like OpenSCAD it's really a niche thing for designs that are highly parametric like fasteners, gears, 3D printed boxes, etc.
Like OpenSCAD using it for normal "irregular" CAD is going to be extremely frustrating. Like editing an SVG in notepad instead of Inkscape.
I still feel like there's a unexplored space where you combine the benefits of both somehow though. Like a code-based CAD but it also has a GUI editor that stays in sync and avoids the need to type in coordinates by hand. That would be extremely difficult though.
I think you can do this if the data representation of operations and values is human readable. The simplest implementation would restrict the language/data format to operations representable in the gui.
Unlike trying to solve the "visual programming" problems, we don't need or desire Turing completeness.
Very interesting indeed!
Speaking of which, I would love to have parametric capabilities in Inkscape.
Edit: oh I guess sketchup is a surface modeler weird thought it was parametric this whole time, lol someone else said it's a polygon modeler
Yeah I don't know what parametric modeling is apparently, I use a mouse/calipers to model stuff not parameters
There is a solid validator plugin you use before you export an STL to make sure the mesh is closed/a manifold
Ah. That's what's doing the constructive solid geometry. Here's the 2009 PhD thesis behind the object merge and difference algorithms inside Manifold. Nice. At last, soundness. This is a long-standing problem. And now there's an open source implementation. Manifold itself is in C++, not Rust, though.
None of this is parametric. That's a different problem. That's where you put in constraints such as A is perpendicular to B, B is 100mm from C, etc., and the constraint solver tries to satisfy all the constraints. Change a dimension and everything adjusts to preserve the constraints. Parametric CAD is all about constraint solving and expressing conflicts to the user. Autodesk Inventor, Fusion, etc. have good constraint solvers.
[1] https://github.com/elalish/manifold/blob/master/docs/RobustB...
This is never going to have the accuracy seen in higher-end CAD circles, which use b-Reps: highly accurate mathematic representation.
Manifold is good for visualization, but to use it as an engine for manufacturing .. its limits will be hit.
Do you know how it compares?
Meshes are only a lossy approximation of the actual geometry, and the errors accumulate as features reference off of earlier features.
A simple example is a line tangent to an arc. The line will only be the correct distance from the center of the arc at one point (one angle) per segment.
In openscad you don't notice the problem because since it's code and you have variables and programming ways of expressing relationships, you would usually not try to derive one thing from another by geometry, instead both things would reference a common ancestor variable. But that's a technical implimentation detail that works around the problem by just not doing a thing that doesn't work. The problem is still there that a valid geometry constraint would produce invalid results.
I do agree that historically, software aimed at building 3d models for games/animations and other digital use was usually called modeling and not cad. I'm thinking of software like 3D Studio Max back in the 90s here.
https://en.wikipedia.org/wiki/CAD/CAM
I notice though that the Wikipedia article for CAD says: "This software is used to increase the productivity of the designer, improve the quality of design, improve communications through documentation, and to create a database for manufacturing."
> No clicking. No undo. Just recompile.
> That's our mascot. Entirely CSG.
> No garbage collection pauses. No floating point surprises from a scripting layer.
And worst of all, the dreaded "and/but honestly":
> But honestly, the main reason is the toolchain.
Am I misreading things?
I only know of another text -> STL AI model, I'm quite a bit more excited about this idea.
Does someone have experience with this?
Anyway, I think using only code for designing 3D objects is a poor design choice. You really need something that is between pure code and pure GUI.
that, and as a prior skill, learn to draw by hand on paper orthogonal and isometric views of 3d objects.
cad is another theory building excercise, but instead of being about processes, its about objects. you want to start from a strong manual/first principles base
Both have really great documentation/examples.
However purely programmatic interface allows doing surprising things which might be hard to achieve with a mouse.
FreeCad is getting somewhere but it is still way behind. The last thing I care about is what language was it implemented with.
Please have a check on a different monitor and browser than you are currently using, as most of the article is unreadable. Code blocks are nigh unreadable, and the screenshots are washed out as if they were HDR with improper tone mapping (I tested both with Firefox on Linux and Safari on iOS).
It's a shame, because it made me gloss over the article.
Oh, and the screenshots have the same issue both on the blog post and on the main vcad.io website. Funnily enough, code snippets on vcad.io have proper readable colors as opposed to your blog (they're still too dim to be comfortable though, but they're readable).
