Most likely you won’t be asking for specific things like “3mm hole 3in from the side”, you’ll say things like “Create a plastic enclosure sized to go under a desk, ok add a usb receptacle opening, ok add flanges with standard screw holes”
In the text to CAD ecosystem we talk about matching our language/framework to “design intent” a lot. The ideal interface is usually higher level than people expect it to be.
You may or may not be right, but your arguments sound like echos of what software developers were saying four or five years ago. And four or five years ago, they were right.
Don't dismiss an AI tool just because the first iterations aren't useful, it'll be iterated on faster than you can believe possible.
I've created (small, toy) transformers and also modeled injection molded parts in Solidworks.
There is a really big difference. It's obvious how programming languages can use tokens for an attention mechanism, which gives them excellent ability to have parallelized performance (versus RNNs, the prior way of relating tokens) with much broader ability to maintain coherence.
I don't know the parallel with brep. What are the tokens here? It's a fundamental architectural question.
But unlike four or five years ago for programming, when the attention mechanism was clear with transformers and the answer was, basically, just "scale it up", we don't even really know where to begin here. So assuming some magic is going to happen is optimistic.
It'd be exciting if we could figure it out. Maybe the answer is that we do away with brep and all tree based systems entirely (though I'm a little unclear how we maintain the mathematical precision of brep, especially with curves, which is necessary for machining -- your machinist is going to throw you out if you start giving them meshes, at least for precision work that has anything with a radius).
While LLMs are a useful tool for software development, if you try asking them the software equivalent of “Create a plastic enclosure sized to go under a desk, ok add a usb receptacle opening, ok add flanges with standard screw holes” you'll end up with the equivalent of “No the other side. No, not like that, at the bottom. Now make it 10mm from the other hole. No the other hole. No, up not sideways. Wait, which way is up? Never mind, I'll do it myself” a lot.
What works is asking them to implement micro feature that you will specify well enough at first try, not to ask them writing the entire piece of software from top to bottom. The tech is clearly not there yet for the latter.
The main difference between Code and CAD is that code is language you're writing to the machine to execute already, so it's pretty natural to just use a more abstract/natural language to ask it instead of the formal one of code, whereas CAD is a visual, almost physical task, and it's more pleasant to do a task than describe it in depth with words.
> Create a plastic enclosure sized to go under a desk, ok add a usb receptacle opening, ok add flanges with standard screw holes
With vague specifications like these, you'd get garbage from a human too.
What works for software, and I suspect for other technical fields like CAD too, is to treat it like a junior developer who has an extreme breadth of knowledge but not much depth. You will need to take care to clearly specify your requirements.
The problem is that this isn't very useful except for the very earliest ideation stages of industrial design, which hardly need CAD anyway.
Most parts need to fit with something else, usually some set of components. Then there are considerations around draft, moldability, size of core pins, sliders, direction of ejection, wall thickness, coring out, radii, ribs for stiffness, tolerances...
LLMs seem far off from being the right answer here. There is, however, lots to make more efficient. Maybe you could tokenize breps in some useful way and see if transformers could become competent speaking in brep tokens? It's hand-wavy but maybe there's something there.
Mechanical engineers do not try to explain models to each other in English. They gather around Solidworks or send pictures to each other. It is incredibly hard to explain a model in English, and I don't see how a traditional LLM would be any better.