> Astra is one-shotting good 3D models from photographs for me.
Right, but, so what? There is very little utility here. Parts that need to be useful need to be designed to spec.
Right, but, so what? There is very little utility here. Parts that need to be useful need to be designed to spec.
But this article is talking about functional parts. A functional part exists because of its spec, usually fails because of some combination of its material, manufacture, and spec. And the spec is chosen with that in mind.
Even working from a text description of a part is error prone because language is imprecise and interpretable. I just don't understand why AI people want to race past actual proper sensible solutions to a problem just to automate generating from text.
If a non-CAD person imagines a part that they need, the chances are very high indeed that either it isn't what they need, can't be made robustly or sensibly, or if it is, it already exists in some meaningful way that can be adapted, because one of tens of millions of other people already wanted it.
This scenario — needing something very specific that can be described only in words and nobody else has ever needed before — is almost imaginary. Most stuff just isn't like that.
Now… if someone were to design an AI CAD package that could remix objects that exist and combine them, perhaps with a GUI tool that allowed a user to identify attachment points, maybe that would be interesting. But a lot of that has been solved in non-AI GUIs already.
Text-to-CAD just isn't as good an idea as it seems. You are not going to be able to magic up some novel invention from a text description without a significant amount of domain knowledge of the words needed to describe a part, and that domain knowledge usually comes from learning CAD!
(Bit like getting a coding agent to write really good code)
And simple parts, sorry, just don't need much CAD skill. Get a CAD package on a free plan, learn enough to make your thing. You will get so much more out of that and it will be easier to make changes. It'll probably have standard tools for adding threads, even.
Even image-to-CAD for a functional part requires a significant amount of understanding of what to photograph and from which angles, etc.
Just last week I had Gemini 3.8 Flash and Antigravity take an existing STL of a part and swap out a piece of it with another design (fan shrouds on a computer case front plate). In the process it created exploded parts diagrams from the STL, created 2D renders from each axis (for its own visual re-ingestion, presumably, since I neither asked for or needed them), projected measurements, and then it implemented my design swap request. Which it didn't do with SCAD, it wrote a Python program and directly manipulated the STL geometries. It went perfectly. A week before that I had GLM 5.3 and Hermes take one model that was intended to fit into a part from another designer's part and change it; I didn't really like the interior part's design so I gave both STL files to Hermes and asked for a new interior part design that could be printed with vase mode to speed it up. It did and the new part is better than the human-designed part I grabbed off the internet.
I had another task mid week where I needed a case for something but didn't have the dimensions, so I just had Gemini do deep research lookup for dimensions and to then spit out a case STL for me. It was boring but functional and a good enough starting point for me to work with.
Right now my wife is enamored with a 3D printed purse design for halloween but the separately printed hinges are a weak design (a circular mortise and tenon rotating hinge). Working with Antigravity again, it's been able to take measurements, rotate parts in space on its own and create me a new object design that's better suited to be printed in TPU. It's held dimensional accuracy and even inferred some dimensions and spacing I didn't have out of the primary purse's shape. It's gone great. Next up will be having it combine all the parts into a single STL so I can do a multimaterial print in one shot, printing the purse in PETG but the living hinge in TPU without assembly needed.
I think "it's here, now" for home and hobbyist CAD needs for functional prints. It's not displacing a mechanical engineer's job yet, but this recent iteration is markedly better than the previous generation of models at spatial reasoning and 3D design because it's suddenly capable of it at all when even 4 months ago it was not.
In your other comment you mentioned "just learn CAD", and I have already, I could have cobbled together all of this myself in Fusion 360, but that would have taken far more time than a few minutes of prompting and walking away. I know enough domain lingo to describe the task well, and if it falls flat I will do it myself, but it's coming along faster than you seem willing to accept.
Could you do meaningful things without domain language you learned the long way?
I don't doubt it is coming along. But as with all of these things, this one is painted into a corner from the very start by using OpenSCAD.
And a mechanical engineer's job isn't just fiddling away in CAD, is it? If it was I would be on the way to being one by now, and I am not.
I see no special barrier for mechanical engineering either. CAD can be represented in text. Statics and dynamics are already calculated in software, simulations are already ran in software. Specs for things are already formalized in both format and notation. All the pieces are there if you squint at it a little, they’re just not quite as easy as software tooling was, but it’s certainly closer than a surgeon’s or plumbers job.
One of the things you get from studying CAD diagrams — like the Solidworks exercises everyone works through — is that real world parts often have surprisingly few dimensioned constraints. A lot more emerges from geometry.
So you can look at a diagram and initially think "where the heck does it define this radius!?" and find that it never needs to, because that radius emerges from tangency, parallelism, perpendicularity etc., combined with fewer measurement constraints.
Specifying it as a measurement would therefore be overconstraint; it might lead to solids that are difficult/impossible to manufacture or erroneous when another measurement is changed.
The diagram will specify the actual driving measurements that come from the part's purpose, with the intent to adapt to different real-world requirements.
Any CAD tool that works from images is going to have to approximate, which will create over-complex models with to many measurements that are more fragile with respect to changes, whereas a design that has geometrical constraints in place that are logical will be simpler and more adaptable.
With functional parts, roughly, form follows function first, and manufacturability second. But you have to understand why, to be able to make a good part. Even (perhaps especially) with 3D printing. But not uniquely. For example, would this tool be able to understand why the draft angles on a plastic part were important, what determines the bend radius of a part that was made from pressed metal, etc.?
I must stress that I am an amateur. But my amateur skills have come from reading and learning about CAD and learning what makes a viable design.
(Sorry… this was a stupidly long answer but I am hungry and I figured I should try to blurt it out before I have to get up from my desk and cook. I've edited it a lot and cut out a bit that I will probably put in another comment later)
And yes, telling it 'add draft angles to make this castable' works.
Then you are not actually getting a model with a constraint system at all. Which is the point of the thing I'm replying to.
CAD constraints are more powerful and flexible than OpenSCAD, and the power comes from analysis of what the part is actually for, not merely what it looks like.
You can't even compel OpenSCAD to keep a line and an arc tangent. If hull() can't do it, you're making it up yourself with maths.
You can use it for basic shapes and very simple geometry. But you can use Tinkercad for that too.
Should you use it for CAD generally: I think not. Because complexity balloons out of control. An AI is going to struggle as much as a human does with a complex part in OpenSCAD.
All the text-to-CAD packages are relying on it because there's lots of simple examples in the training set, and because it is declarative — there's a belief that there is a mapping from text to declarative spec and from declarative spec to an object.
But it is the wrong choice for flexible designs that adapt correctly when measurements are changed.
It's clear to me that "AI CAD" developers who think OpenSCAD is adequate to the task have a fundamental misapprehension of the capabilities of the technologies they are actually seeking to replace. OpenSCAD is not representative of the nature or capabilities of modern CAD.
I think that if you are trying to make an adaptable functional part you would be better to start from CAD drawings, with proper constraints on them, and that an AI CAD package should be interacting with those (there are some attempts to do just that).
It's just not that difficult in a modern CAD package, it's not arcane or obscure.
But if you're going to be using code-CAD, you want a programming package that can represent fundamental aspects properly. OpenSCAD cannot.
CadQuery, to be fair to the authors of this post, does now have an experimental 2D constraint solver:
https://cadquery.readthedocs.io/en/latest/sketch.html#constr...
And it has a proper bRep kernel, so it can represent vertexes, edges, arcs and faces in mathematically abstracted (not mesh approximated) forms, and do operations on those (including fillets, though it has its weaknesses there inherited from OpenCascade).
I think an AI that could operate properly on CadQuery models and implement appropriate sketch constraints with an awareness of their implications, choose the right operations, make use of libraries, etc., would be a lot more capable. But it's so much further down the line than people think based on these OpenSCAD toys that produce trivial parts.
I'm a Onshape person myself, and try to contsain every thing in a way you describe. Including variables to quickly change important parts of the drawing.
But I also 100% believe half my designs could be done with tinkercad. And this be useful for me.
Last thing I designed and printed was a vacuum hose adapter. Ai cad could have done that. Including variables with sliders for size in both ends.
If you think constraints are a goal in itself, I don't know what to tell you. Constraints are a tool to generate geometry. If I make a design in Fusion360 or FreeCAD using constraints, and create an STL in the end to print, why would that be any different from using OpenSCAD and having variables in there to represent functional measurements? (and yes I've designed parts with constraints.) What are constraints but a tool for the operator to (visually) represent relationships between measurements? Variables and constraints are just different ways to express my model's measurements and locations in function of a set of fundamental inputs.
Is CSG less 'powerful' than brep? Of course it is. AI can do brep as well. Do you need constraints and solvers to do CAD? Of course not. I mean I'm not going to argue with shifted goalposts on what 'real' CAD is here, I don't care about what other people think about this. What I see is that AI is perfectly capable of making quite intricate 3d models today, passing people who argue about whether what the AI does is 'real' CAD left and right. Just like it passes those programmers who spends their days arguing that AI code is somehow inherently worse left and right. I don't care, I get results regardless of those people. What I meant with my original comment is that the assertions that AI today doesn't understand 3d relationships from 2d images is plain wrong, it understands it well enough to not only make 3d models, but to make it in ways a lot more conceptual than 'assemble triangles with skin()' (in OpenSCAD terms, but I had it do that in raw Python in models 6 months ago, when frontier models didn't have these spatial capabilities).
And same for CAD. Who cares about intermediate representation? If an AI just generates results directly, I don't care if it uses CSG or brep or has a writer for dwg files and just does moveto() and lineto() on that. Your comment suggests you think AIs are for doing things the way humans do to get a certain result. I don't care, I just want the results. Of course there is provenance and versioning future proofing and all, I'm not claiming CAD or 3d design or video editing software will go away - at least not right away. But they will have to adapt to being shortcuts for the AI to use them more efficiently than reimplementing their algorithms, or wither away.