OpenSCAD is kinda neat

https://nuxx.net/blog/2025/12/20/openscad-is-kinda-neat/

by c0nsumer • 7 months ago

327 253 7 months ago

nuxx.net

ai-christianson2• 7 months ago

Is OpenSCAD still being maintained?

aeonik2• 7 months ago

Yes. https://github.com/openscad/openscad

bdcravens2• 7 months ago

It's worth noting they haven't had a new "release" in 4 1/2 years, so you'll have to build it yourself or download a development snapshot

https://openscad.org/downloads.html#snapshots

starkparker• 7 months ago

More usefully, https://github.com/openscad/openscad/issues/3640

c0nsumer3• 7 months ago

The last release was 2021.01 but the GitHub repo seems to be recently updated. So I'd say... Maybe?

That said, there are often times software gets so stable that not having a new release for years is fine. Maybe this is one of them?

(I'm very new to OpenSCAD so I haven't run into bugs yet... But maybe it's pretty solid?)

crazysim• 7 months ago

Apparently the nightlies are the one to use. At least, they build it for Apple Silicon in those.

floating-io• 7 months ago

Yes. The "official release" is just so old as to be useless at this point. They should either update it or take it down and point people at github or something, IMO.

I use the latest version all the time. The newer renderer ("manifold", IIRC) is much faster, and there are newer facilities that make it possible to build 3MF files containing multiple objects for multi-color printing, though that takes a bit of thought to do correctly.

MattRix5• 7 months ago

Yes everything this person said is correct. The Manifold backend is no joke, probably 100x faster.

To do multi-color printing it’s pretty easy now, just turn on the poorly named feature in preferences called “lazy-unions”. This will make it so that each top level object in your file gets exported as a separate subobject in the 3mf file.

MattRix5• 7 months ago

Yes, but the main downloads on the site are very old for some reason. Just get the nightly version instead, and then in Preferences -> Advanced -> Backend change it to “Manifold”. It will make your models “render” 10x faster (or more!).

bdcravens2• 7 months ago

I believe that's the default now (at least in the latest MacOS nightly)

overtone1000• 7 months ago

I completely agree! https://overdesigned.org/shhh-dont-move-it-cant-see-us-if-we...

convolvatron• 7 months ago

I love the model, it's nice to be able to generate things parametrically instead of grabbing knots with the mouse. so I use scad pretty often.

but it has real problems - the language is weird and unfortunate. not anything super fatal, just the obvious product of evolution that would be more cohesive if it were architected wholesale

  epsilons are really unfortunate. you have to expect that after getting what you want in the whole, you're going to have to scan over the whole thing and look for cracks or collision where there shouldn't be 

  performance is quite sad. here you are happy going back and forth between the view and text windows, but as you go on, it starts taking .. minutes.. to update the view once you have a reasonably complicated geometry

  high-level operators would also be nice. I made the mistake of using a thread library once, not only did that make my model unrenderable, there was so much noise in the model and the manufacturing process I had to make 3 expensive test prints in sintered nylon to get the fit right. (I'm thinking an annotation on a cylinder that says 'standard 1mm thread')

MattRix5• 7 months ago

It actually renders things incredibly fast if you get the nightly version and set the backend to Manifold. It is probably 100x faster (!!). In fact it renders so fast that I put a render() command at the top of my hierarchy so that everything just renders all the time, it’s faster and more performant. I make incredibly complex models with it too, with hundreds of holes, complex svg files with text in them, etc.

coryrc9• 7 months ago

Why not just press F6 instead?

WillAdams29• 7 months ago

If you're inclined to use Python there is:

https://pythonscad.org/

bradfitz• 7 months ago

I find myself using OpenSCAD regularly to 3D print little things for the house. (Most recently: hooks to attach Christmas lights to our roof deck's glass walls)

And when something gets too trick, ChatGPT is amazing at writing in it. Often it nails the whole design in the first try, like https://bsky.app/profile/bradfitz.com/post/3maelwomyw22n to mask off certain Raspberry Pi pins to make reassembly of projects easier later.

jasonthorsness• 7 months ago

OpenSCAD is great! I used it to create a bunch of things to cut on a CNC router over the years. Best achievements were a scale model of Mount Rainier and some one-piece picture frames with text cut into them.

charlie-83• 7 months ago

Just started using OpenSCAD recently and love it. While most CAD tools have a million features to learn, OpenSCAD is completely described by a cheat sheet you could print on a piece of A4 (like most programming languages).

I would really recommend using the git master than the latest release though. The last release was 2021 but they are still actively working on it and it's much faster now.

I also have to recommend the BOSL2 library which means you don't have to implement all of those one million features from typical CAD software yourself. Its definitely got a bit of a learning curve but the fact that you can always default back to vanilla OpenSCAD and that you can actually see how stuff is implemented makes it much more satisfying to me to learn than learning what all the traditional CAD GUI buttons do.

porkloin3• 7 months ago

Commenting off of you since I wrote all of this and then realized it's basically exactly what you're saying. But to +1 everything you just said in my own words:

I love OpenSCAD. I've been 3D printing for a while, but I never really got to a place where I could design interesting parts until I started to get the precision of doing models in code. Sometimes it is slower, for sure.

Every time I've used as a CAD GUI program I would get to this point where I would need to alter a single dimension by 0.25mm and realize that _all_ of my fastener holes, cutouts, etc have to be nudged with the keyboard or mouse to accommodate it. The input devices lack precision for that kind of task, and having to repeat the operation dozens of times (or bulk select) gave me a terrible sinking feeling, and I'd often just step away and give up on the design at that point out of frustration. I try to approach everything in OpensSCAD in a way that means I never have to experience that feeling again.

I will also say that doing everything from scratch in OpenSCAD would be it's own special kind of hell. Libraries like [BOSL2](https://github.com/BelfrySCAD/BOSL2) provide a good set of core ideas and preferences that help set you on a good path. A good example: BOSL2 shapes tend to have a "center origin" by default, which is different than the OpenSCAD default, but makes doing transforms later way easier.

Anyway, happy to see OpenSCAD getting some attention here :)

0_____0• 7 months ago

A properly parameterized model shouldn't have the issue with having to nudge everything manually after a trivial change.

I had the change the height of an entire enclosure to accommodate a taller than anticipated PCB, and simply edited the sketch at the top of my design tree that defined the overall dimensions.

It took about 5 minutes to adjust the odd broken fillet and change some mates in assembly and it was done. No fidgety mouse movements. I actually do a lot of mech design on a laptop with a trackpad, arrow keys for view changes and numeric dimensioning for 95% of everything else.

Arodex3• 7 months ago

Every time I've used as a CAD GUI program I would get to this point where I would need to alter a single dimension by 0.25mm and realize that _all_ of my fastener holes, cutouts, etc have to be nudged with the keyboard or mouse to accommodate it.

What.

This makes no sense. This isn't PowerPoint; your holes and cutouts are supposed to be parameterized. How are they even supposed to be at the proper position in the first place?

As a CAD user, this is like e.g. a coder seeing someone write code with global variables everywhere.

abdullahkhalids• 7 months ago

Every time I've used as a CAD GUI program I would get to this point where I would need to alter a single dimension by 0.25mm and realize that _all_ of my fastener holes, cutouts, etc have to be nudged with the keyboard or mouse to accommodate it.

I am just starting to learn CAD and FreeCAD - also dabbled a bit in OpenSCAD. But I do know that FreeCAD has Spreadsheets [1] and Configuration Tables [2] which allows you to define your model parameterically and changes values as needed.

How good this is, I don't know yet.

[1] https://wiki.freecad.org/Spreadsheet_Workbench [2] https://wiki.freecad.org/Configuration_Tables

zargon2• 7 months ago

Every time I've used as a CAD GUI program I would get to this point where I would need to alter a single dimension by 0.25mm and realize that _all_ of my fastener holes, cutouts, etc have to be nudged with the keyboard or mouse to accommodate it.

There seems to be some fundamental misunderstanding of CAD here. I can't imagine how you could even design something in CAD in a way that you would end up in this situation.

girvo• 7 months ago

I would get to this point where I would need to alter a single dimension by 0.25mm and realize that _all_ of my fastener holes, cutouts, etc have to be nudged with the keyboard or mouse to accommodate it

Thats surprising! Last time I used software like this (Inventor, back in ~2005-2006) constraints meant that I didn't need to do this at all

RobotToaster2• 7 months ago

Every time I've used as a CAD GUI program I would get to this point where I would need to alter a single dimension by 0.25mm and realize that _all_ of my fastener holes, cutouts, etc have to be nudged with the keyboard or mouse to accommodate it.

I can see how you would end up in that position

You need to add constraints to your sketches. In other words tell it that the hole needs to be x distance from certain lines.

If you don't do that what you get is the equivalent of hard coding a hole location in OpenSCAD. I guess OpenSCAD just forces you to think parametrically.

Also in fusion 360 make sure timeline editing is on.

amelius• 7 months ago

I sometimes think that "parametric" is not the right description or the word is used in the wrong way.

As an example, consider a bar with a constrained length, e.g. 1000mm. I want holes in the bar every 100mm (not a strange requirement). Now I change the length constraint to 800mm. Consequently, the number of holes should change. But this seems not possible in a "parametric" modeler. Maybe I'm missing something, though.

moebrowne3• 7 months ago

I would really recommend using the git master than the latest release though.

This. The master version is so much further ahead of the last tagged version. The render time can be orders of magnitude faster for more complex models.

jasongill• 7 months ago

It appears that regularly-updated builds are available here: https://openscad.org/downloads.html#snapshots

or with Homebrew you can do `brew install --cask openscad@snapshot` to install the latest snapshot version.

Or, browse all the snapshot builds here: https://files.openscad.org/snapshots/

(as of this comment, the last snapshot build is from yesterday)

cm2187• 7 months ago

Agree but you quickly run into its limitations. Like if you 3d print something, you need to eliminate when possible sharp edges. That's not fun to do with OpenSCAD.

m4rtink3• 7 months ago

BOSL2 can help with that:

https://github.com/BelfrySCAD/BOSL2/wiki/rounding.scad

https://github.com/BelfrySCAD/BOSL2/wiki/Tutorial-Rounding_t...

m4rtink3• 7 months ago

BOSL2 is SO nice and powerful, can also highly recommend it! :)

exasperaited11• 7 months ago

OpenSCAD isn't a CAD tool, IMO. It does nothing at all to aid your design. It barely even helps describe it in any abstract way.

It is a useful tool for programmatically describing either very simple or heavily geometric objects. For everything else it's the wrong tool.

voxleone2• 7 months ago

I'd put it this way: CAD = Computer-Aided Design, i.e., software that assists in the creation, modification, analysis, or optimization of a design.

OpenSCAD clearly qualifies because it creates precise 2D/3D models; supports parametric modification; enables reproducible designs; produces manufacturable geometry (STL, DXF, etc.). The fact that it is code-based does not disqualify it. By the same logic, CadQuery, SolidPython, or FeatureScript would also not be CAD - which is not a position held in engineering practice.

gortok• 7 months ago

Can you link to this cheat sheet?

WillAdams29• 7 months ago

Presumably:

https://openscad.org/cheatsheet/

Note that updating it is one of the blockers for a new release, so it doesn't include some newer features/syntax

There is also:

https://cubehero.com/2013/11/19/know-only-10-things-to-be-da...

FWIW, when I need to rough something out in OpenSCAD, I usually use:

https://www.blockscad3d.com/editor/

Robdel12• 7 months ago

OpenSCAD has become my go to with my 3-D printer for dumb little things. And the best part is LLMs are getting decent / pretty good with it!

My favorite thing I’ve printed is a little downsize coupler for the cool shirt system I built for my spec miata. It’s realllly silly & small thing, but it saved me!

yehoshuapw• 7 months ago

worth also looking at cadquery, build123d and similar

https://github.com/gumyr/build123d

anfractuosity• 7 months ago

It's super useful, been using with my 3D printer to print things such as an adapter to connect a Canon EF lens to night vision tube and parts to link motorised linear stages together.

Currently I'm playing with a gear library which is part of BOSL2 (https://github.com/BelfrySCAD/BOSL2/wiki/gears.scad), to make something to rotate a polariser in my microscope.

constantcrying4• 7 months ago

OpenSCAD is very cool, but completely unusable once you understand how great state of the art CAD Software like Fusion or Onshape is.

The big distinction is that those work implicitly, while OpenSCAD requires you to be implicit.

d_silin• 7 months ago

excplicitely, you mean?

WillAdams29• 7 months ago

The thing is, I've crashed-and-burned every time I've tried to do traditional 3D CAD --- the closest I've come to success was making it all the way through the tutorial for Dune 3D:

https://news.ycombinator.com/item?id=37979758

https://news.ycombinator.com/item?id=40228068

OpenSCAD "just works", even on quite limited hardware, and if one has trouble modeling something, well, arriving at a solution is just a matter of learning the appropriate mathematics.

constantcrying4• 7 months ago

To be honest, I found Fusion 360 and Onshape very intuitive to learn.

and if one has trouble modeling something, well, arriving at a solution is just a matter of learning the appropriate mathematics.

Which is the terrible thing about OpenSCAD. YOU need to derive the equations. In a modern CAD program you define the constraints on the object and the equations are derived for you.

kiba3• 7 months ago

The way I learned CAD is the same way I approach programming projects. I tackle simple, bite size projects, which then increase in complexity until I have the skills necessary to tackle big complicated projects.

I found that standard CAD to be no simpler than OpenSCAD. Really, the biggest disadvantages that OpenSCAD have is usability and a library which is fixed by using BOLS2.

BOLS2 has the same problem as standard CAD, it is overwhelmingly big. In some cases, I didn't know features were already in BOLS2 so I don't have to reinvent the wheel writing my own inferior library.

So, how to tackle it? Same thing as any learning projects. I just tackle it in bite size chunk.

culi2• 7 months ago

I'm a programmer. I once had an idea stuck in my head for a 3d model that I just needed to get down somewhere. I tried learning the basics of AutoCAD but after 2 days of tutorials I still felt overwhelmed.

I looked into alternatives and learned about OpenSCAD. The immediate visual feedback makes picking up the language a breeze. Within an hour of downloading I familiarized myself with the language and had manifested my idea into a 3d model

I think that's a perfect example of a use-case where OpenSCAD shines. It's extremely easy to pick up if you have programming experience and it might even be a good thing to learn before moving onto more professional CAD software. From a teaching perspective, being able to have almost immediately-useful output is priceless

WillAdams29• 7 months ago

The BlockSCAD folks are hoeing that row quite effectively to my mind:

https://www.blockscad3d.com/editor/

I just wish that they'd add the balance of the language/fix some bugs.

constantcrying4• 7 months ago

I think that modern CAD software, like Onshape or Fusion 360 is quite easy to learn. I have no doubt that AutoCAD is difficult to grasp, but it is not a good representative of what is possible.

It's extremely easy to pick up if you have programming experience and it might even be a good thing to learn before moving onto more professional CAD software.

No, it definitely is not. OpenSCAD makes you think exactly the wrong way about CAD, because it forces you to reason explicitly about your model, when that is something which you need to let the CAD Software do for you. Modern Parametric CAD works by the user defining constraints, which the Software uses to derive the shape of the model, this is not something which conceptually exists in OpenSCAD.

From a teaching perspective, being able to have almost immediately-useful output is priceless

Which is something which modern CAD does just as well.

elcapitan• 7 months ago

For me as a casual 3d-modeler, my favorite thing about OpenSCAD is that I don't have to learn a new application the size of Photoshop with everything hidden 7 levels deep in some menu that is probably intuitive for some people who learned CAD in the 80s.

Instead it's basically like graphics programming, with a couple of basic primitives, some linear transformations and a bit of set theory. When I do a model a month and get back to previous work, I read a few lines of code and know exactly how I achieved the result.

unbelievably• 7 months ago

I was once a big OpenSCAD user myself but I'm really skeptical that there are many use cases where it's actually more intuitive than a traditional CAD program, even if you're a programmer. It's true CAD programs have a huge amount of features but the basic sketch, extrude, revolve, and loft tools aren't conceptually difficult and are basically the same between Onshape, Fusion, Solidworks, etc. Those tools are sufficient to make 99.99% of OpenSCAD models I'm seeing.

I also have the opposite experience about understanding previous scripts. Unless it's dead simple I'm usually thinking why the hell did I multiply this thingy by sqrt(3)/2 plus this other thing. Maybe a documentation problem, but it's inescapable that sometimes you need a lot of math for what are trivial constraints in an interactive sketch. A real CAD program will let you roll back to any feature to figure out how it's constructed step by step so there's really nothing to decipher.

WillAdams29• 7 months ago

I've been trying to model joints for woodworking, and in traditional tools, the shapes I wish to arrive at verge on nightmarish, while I was able to knock them out in OpenSCAD in pretty short order --- except that when I sent a 1" x 2" x 1" test joint to a CAM program, it took some 18 minutes and generated a ~140MB G-code file, hence my working on:

https://github.com/WillAdams/gcodepreview

IshKebab• 7 months ago

Yeah I agree. OpenSCAD is good for highly parametric modelling: fasteners, gears, generative art, ... that's about it. Most things aren't like that, and a traditional parametric CAD program is 10x easier.

wat10000• 7 months ago

The older I get, the less I want GUIs. If I want to rotate something, I want to type “rotate,” not find the rotation icon or menu item or remember the keyboard shortcut or whatever.

I know this is not typical, and nothing against folks who see it the other way. But OpenSCAD fits the way I think and want to work better than the more “normal” tools.

rcpt• 7 months ago

I haven't tried the latest models but for at least a year LLMs have been mostly able to generate openscad to match my descriptions.

It's neat that I can tell the computer what I want in words and then have that object come out of the 3D printer

WillAdams29• 7 months ago

The great thing about OpenSCAD is that it makes it easy to 3D model things which may be described using spheres, cylinders, and cubes which are stretch, and/or rotated, and arranged in 3D space.

The awful thing about OpenSCAD is that what one can model in 3D is limited by one's ability to mathematically stretch, rotate, and/or arrange spheres, cylinders, and cubes in 3D.

For folks who want "real" (read mutable in normal terms of scope) variables there is a Python-enabled fork (which should become part of the main release presently:

https://pythonscad.org/

M_bara• 7 months ago

Or perhaps take a look at cadquery? It’s also pretty neat - http://cadquery.readthedocs.io/

culi2• 7 months ago

There's also OpenJSCAD. Which, being JavaScript ofc, can run in the browser

https://openjscad.xyz/

https://github.com/jscad/OpenJSCAD.org

spwa4• 7 months ago

Don't people think this is one tool that would greatly benefit from using the very fastest languages available? Where's the C++, Rust, maybe even FORTRAN version?

rafabulsing• 7 months ago

Re: JS based CAD, there's also replicad, which I've used previously and found to be really good.

https://replicad.xyz/

xixixao3• 7 months ago

From my testing, the CSG operations, with post-processing, don’t produce watertight meshes. And being focused on printing, it doesn’t support different colors for the CSG operands. My use case is animation/games, so I’m reimplementing the CSG with a watertight b-rep.

IgorPartola3• 7 months ago

Not just that but it also positions everything in absolute coordinates and does not have the ability to reason about solids, just surfaces. Basically if you want to model something like a bolt you need to create a cylinder for the shaft, a separate head of the bolt, and then a thread profile you can rotate around the cylinder. You must ensure there is enough overlap between these three separate parts so the resultant object is a single surface and not three separate ones.

You can use modules to create a semblance of relative measurements but you still cannot do things like “attach this surface of object A to that surface of object B)”. In practice this means that if you want to create something like a spacer or a bracket you can do that easily enough. But if you want to make a part that matches some real world design you are stuck doing a lot of caliper measurements and math to try to create a part that lines up correctly. The you 3D print it and find that you positioned some hole based on its edge and not center and so nothing quite fits.

OpenSCAD is easy to start but difficult to scale because of these limitations and because once you hard-code any measurement you are stuck with it. The “proper” way to do this is to give everything a variable but honestly that makes reasoning about how to line things up even more difficult. “Does base_width include the width of the vertical walls? What about the margin to make the parts fit together?”

I have never been able to understand how things like FreeCAD lay out their UI. TinkerCAD is relatively simple but clearly a lot less powerful. I did try cadquery which solved a lot of OpenSCAD’s issues by having all offsets be relative by default but also introduces a few issues of its own.

One tip I will give about OS: grab a copy of the latest beta/dev release. The renderer is several orders of magnitude faster.

coryrc9• 7 months ago

BOSL2 allows attaching when you define attachment points or something with attachment points defined for you (most everything in BOSL2).

Manifold backend also eliminates the need to avoid coincident faces.

somat• 7 months ago

but you still cannot do things like “attach this surface of object A to that surface of object B)”

Sure you can, but openscad is an imperative language so you need to do it in an imperative manner.

    a_cube_loc = [10, 5, 5];
    a_cube_size = [2, 4, 1];
    b_cube_loc = [a_cube_loc[0], a_cube_loc[1] + a_cube_size[1], a_cube_loc[2] ];
    b_cube_size = [2, 4, 1];

   translate(a_cube_loc) cube(a_cube_size);
   translate(b_cube_loc) cube(b_cube_size);

It would be nice to have more declarative constraints. The solvespace file format is plain text and it almost feels like you could write it by hand, but that would be a lot of manual record keeping. and you would loose all that imperative goodness. Perhaps you could have an imperative layer(say python or lisp or forth) that outputs the declarative layer(solvespace) and then solvespace renders(picture or stl) the declarative layer.

m4rtink3• 7 months ago

Let me introduce to the awesomness of the BOSL2 screw module:

https://github.com/BelfrySCAD/BOSL2/wiki/screws.scad

c0nsumer3• 7 months ago

You must ensure there is enough overlap between these three separate parts so the resultant object is a single surface and not three separate ones.

(Post author here.)

This was a very weird thing to me I ran into and have thus far just sort of... accepted.

In Fusion, and other CAD software, if I have two faces end at the same point, unless I've specifically said to create them as separate bodies, they are joined, because they share a plane.

In OpenSCAD, in the tutorial, it has you extend an object 0.001 to ensure they overlap. To quote:

In the example above, the second cube sits exactly on top of the first cube. This is something that should be avoided, as it’s not clear to OpenSCAD whether the two cubes form one object together. This issue can be easily solved by always maintaining a small overlap of about 0.001 - 0.002 between the corresponding objects. One way to do so is by decreasing the amount of translation along the Z axis from 10 unit to 9.999 units.

This struck me when making the example in my post. In line 47 I specifically add 1 to heightCompartment to ensure the opening extends past the top of the main body. If I didn't do that, this happens during preview: https://imgur.com/a/Amc1dK6 (That's an exported image from the latest nightly of OpenSCAD.)

But it doesn't happen during the actual render?

Still, that just feels... like there's something going on with a floating point value or something which, programatically, is probably correct... But from the perspective of someone trying to design something feels Very Wrong. Because I have a 20mm high box, I subtract a 19mm high box from it, starting 1mm up from the base. Why shouldn't the top be open? Why is it acceptable for it to be maybe kinda open but broken by design?

ur-whale5• 7 months ago

I have never been able to understand how things like FreeCAD lay out their UI.

I'm 100% with you there. One of the most utterly confusing UI I've had to deal with.

And I suspect the answer is : the FreeCAD devs don't either.

NortySpock• 7 months ago

I ended up adding the https://github.com/BelfrySCAD/BOSL2 library to OpenSCAD and it had some reasonable options for some gear and rack-and-pinion modeling that I needed to do.

(3D printing a sacrificial gear for a seat position adjustment mechanism)

ai-christianson2• 7 months ago

I've had really good luck with https://github.com/SolidCode/SolidPython

RobotToaster2• 7 months ago

The great thing about OpenSCAD is that it makes it easy to 3D model things which may be described using spheres, cylinders, and cubes which are stretch, and/or rotated, and arranged in 3D space.

It also has hulls and minkowski sums, which are powerful once you understand them.

WillAdams29• 7 months ago

Aren't hulls just a direct connection of the edges of two shapes (which could be simulated by a series of duplications) while Minkowski is "just" a matter of putting spheres along the edges of an object to round the straight edges?

So, spheres and cylinders and cubes placed, rotated, stretched and placed mathematically.

JoshTriplett• 7 months ago

Another interesting option is FreeCAD, which is scriptable in Python but its primary interface is a GUI. So you can use a script to create things programmatically, edit graphically, or both.

criddell• 7 months ago

FreeCAD sounds great but in practice it’s sooo slow.

If you are coming from SolidWorks, Fusion360, Inventor, or OnShape, it won’t take long before you start finding that there are a lot of things missing from it.

WillAdams29• 7 months ago

Isn't the Python scripting in FreeCAD just a direct representation of the internal object model?

It's _not_ something which was designed for ease of use, or rational semantics, or to facilitate expression.

coryrc9• 7 months ago

Also you can use the new backend by writing C++: https://github.com/elalish/manifold

Which avoids using the OpenSCAD language, but also means you can't use BOSL2. Might as well use FreeCAD.

pca006132• 7 months ago

It has many language bindings, including python and js. Though the js backend is not parallel because it uses wasm, and we had problem with mimalloc memory usage with pthread enabled.

jandrese3• 7 months ago

You can also make more complex shapes if you're willing to define points, even on a 2D plane that you can then extrude. Downside is that it's basically a MENSA test to define all of the points in the correct order. I've done it a few times, but it's never fun.

anthk• 7 months ago

Solid of revolutions and Bezier curves. That and some elementary Calculus will help everyone a lot.

tombert• 7 months ago

I think people should also give Bowler Studio a shot. It has a pretty decent Java-based CAD thing, and it even has built in Clojure support, with physics simulation support and everything. I really like it.

ur-whale5• 7 months ago

https://pythonscad.org/

Thanks for this, didn't know about it.

How does that compare to solid python 2?

https://github.com/jeff-dh/SolidPython

WillAdams29• 7 months ago

It's native and more direct.

Rather then adding an additional compile cycle:

- run Python code to generate OpenSCAD code

- render OpenSCAD code to see output

OpenPythonSCAD creates a .py code window in the OpenSCAD interface which one interacts with in the same way as a .scad code window (there's even basic support for the Customizer).

I suspect it would be really easy to port SolidPython to work w/in OpenPythonSCAD (if it hasn't already been done)

TOGoS2• 7 months ago

The awful thing about OpenSCAD is that what one can model in 3D is limited by one's ability to mathematically stretch, rotate, and/or arrange spheres, cylinders, and cubes in 3D.

Not at all. You can build any polyhedron you want using the polyhedron command.

Which would be an enormous pain to write out by hand every time, but I wrote a function once upon a time to generate a polyhedron from a stack of layers, each of which is a list of points, and haven't had to mess with old cubes and spheres since.

One annoying thing is that the default way of writing programs in OpenSCAD uses 'modules', which are a bit limited compared to functions (you can't store them as values to to functions or other modules). I worked around that by writing a module that interprets arrays (think S-expressions) that representing the shape, and then just build up that S-expression-like thing with functions and whatever.

Once you've built your own programming language inside OpenSCAD it's perfectly usable. :-)

This might sound like sarcasm but I actually do prefer this to dealing with Python's mutable state jungle / package management nightmare.

WillAdams29• 7 months ago

Fair point.

This sounds _fascinating_ have you posted your code or written this up in a math journal? Link?

I don't touch polyhedrons in OpenSCAD because the logic of point placement mystifies me --- a tool such as you describe would make life a lot easier for a lot of folks, esp. if there was a way to use it to import a series of SVG files which could be used to define the points interactively.

I sometimes wonder if the key to future computer usage would be a series of Domain Specific Languages each intended for a given task:

- 3D == OpenSCAD

- 2D == METAPOST

- SQL == databases

- TeX == text/page composition

- sed == text

(and yes, I know this is the Unix ideal)

but such languages seem to be most successful and most approachable to typical users when they are paired with a front-end which affords editing, previewing, and, direct interaction.

I'm actually nuking my Python install right now, because I got it into a state where I couldn't get Fullcontrol G-code to run, so I agree that the state of Python package population is pitiful, hence of course, the XKCD:

https://xkcd.com/1987/

JonathanRaines2• 7 months ago

Also check out CADQuery and or build123d (python equivalents)

alhirzel• 7 months ago

+1 for CADQuery - it lets you easily specify surfaces as the basis for manipulation, and results in much less fragile designs than OpenSCAD.

Ccecil2• 7 months ago

If you are a programmer OpenSCAD is likely for you. It certainly has benefits in things that are repeating patterns (gears and such)...and if your mind is good at visualizing things in "code" things will likely go a lot faster.

I personally do better with CAD software such as fusion or freecad since my mind doesn't work in the code realm since I have more of a hardware mindset. Translating the picture in my head to code is more difficult than drawing it using the standard CAD set of tools.

My opinion on OpenSCAD is that it is a very useful piece of software which many have used to make some very interesting things. If you have a background in code I recommend giving it a go. I largely view it as "the coder's CAD".

shmeeed• 7 months ago

I was just about to say the same: OpenSCAD is CAD for programmers. It's very different from what's generally considered "CAD".

That's not necessarily a bad thing; there's a clientele for it, especially here on HN. But as a mechanical engineer who's used quite a few industry standard CAD systems, I'm sorry to say I wouldn't touch it with a ten foot pole.

Funnily, just a few days ago I tried FreeCAD, and found it to be better than I had expected.

ThrowawayTestr2• 7 months ago

FreeCAD feels like blender before the UI revamp. I can tell it's powerful but the UI is opaque to me.

Ccecil2• 7 months ago

I switched from Fusion to Freecad just before the 1.0 update.

Freecad 1.0 is a gamechanger IMHO. It so far has suited all my needs as well as being significantly easier to use than the pre 1.0 versions.

cluckindan• 7 months ago

For functional-oriented programmers.

There is no explicit iteration, so if you want to do flexible spacing for any reason, like distribute a feature evenly along a dynamic length, you need to use recursion.

fcpk• 7 months ago

openscad is quite nifty for small geometric projects. unfortunately it lacks some Features that make most bigger cad programs really useful... for example: - the ability to select faces/paths from a render, which can be hugely helpful when modifying complex models. - the ability to do constrained sketching in both 2d and 3d - caching at intermediate render levels - nested Projects and joining parts with mechanical constraints. it's still pretty nifty but very niche. I personally would dream of having the tools of a tool like fusion 360 or Catia, but in a gilly textual progemmatic way, while keeping the ability to select objects from the rendrr view.

coryrc9• 7 months ago

It does have caching, but you are otherwise correct. I would also add that it can't do arcs; any curve is discretized immediately upon creation.

WillAdams29• 7 months ago

If you want arcs in a DXF (or G-code), I've been working on that in:

https://github.com/WillAdams/gcodepreview

khufiya• 7 months ago

I've been experimenting with using Claude Code and the Gemini CLI to generate OpenSCAD with the renderer in the loop.

https://github.com/rahulgarg123/openscad-mcp

It’s still strictly worse than what these models are capable of for general-purpose coding, but for simple tasks where precision isn't the bottleneck, it's surprisingly decent.The "aha" moment for me was an image-to-object workflow: found a geometric design on the web --> generated OpenSCAD to match the image --> 3D printed it. Going from seeing a JPEG to holding the physical object in a few hours.

timonoko4• 7 months ago

I have solved the only problem OpenSCAD ever had and that is

  total lack of interactivity.

https://youtu.be/eG5lhLYvihQ?si=ehet5COZhiNrcK9b

timonoko4• 7 months ago

Now they say newest version of OpenSCAD has this functionality builtin. It took only a year.

xixixao3• 7 months ago

This is important and should be a given. But the more interesting challenge is to highlight the object you’re editing (where your cursor is). It’s not clear even how to exactly visualize it (it could be inside subtract of union of subtract etc).

ifndbdb• 7 months ago

The OpenSCAD kernel is significantly overrated in my opinion. Many operations take ages to compute or are not possible at all

Ok if you want to generate a couple of cubes, but if you want anything advanced the kernel quickly falls apart

coryrc9• 7 months ago

It's switched to a new backend https://github.com/elalish/manifold

Which you can also use directly instead by writing C++. Trivial operations are two orders of magnitude faster and complex ones every faster.

timonoko4• 7 months ago

The openscad-nightly is lightning-fast, but makes occasional occlusion errors.

Assuming you make all the necessary adjustements in preferences.

seamossfet• 7 months ago

How does this compare to something like Zoo?

cpeth• 7 months ago

Check out https://zoo.dev/

I went from OpenSCAD -> cadquery/build123d -> Zoo/KCL

It still is early days, and it needs some more helper functions but it's really nice having two-way capabilities (not just code -> model, but also the reverse).

Of course having Text-to-model as a first class citizen is also nice.

dbuxton• 7 months ago

I have played with this but been underwhelmed. However I do think probably on the right track.

I know the ecosystem not-at-all (sum total knowledge of the CAD ecosystem is that my kids got a Bambu printer for Hanukkah) but it feels to me that current LLMs should be able to generate specs for something like https://partcad.readthedocs.io/en/latest/, which can then be sliced etc.

Curious to know what others think? I come at this from the position of zero interest in developing the fine design skills needed to master but wanting to be able to build and tweak basic functional designs.

bob778• 7 months ago

I want to like Zoo but the rendering engine is so buggy currently that it’s not really usable for more than simple shapes. The text-to-CAD feature they highlight is slow and error-prone, so much so that they explicitly use a “prebuilt” version in the tutorial, and each time I tried it, it gave tool errors or took so long I just did it manually.

bilsbie• 7 months ago

FYI I’ve had really surprising success using AI to generate openscad code.

And even if it’s not perfect it saves a lot of time looking up the documentation and generally gets the relationships between objects right.

WillAdams29• 7 months ago

There is at least one blind designer who has been using this approach to surprisingly good effect:

https://makerworld.com/en/models/2040939-accessible-christma...

cmrdporcupine• 7 months ago

I came here to ask how good LLMs are at working with this. I wonder if a person could take it a step further with some MCP tools that the agent could use to verify and work with the design.

zihotki2• 7 months ago

Mind you, it can't export to step file. That makes it impossible to re-use the models in other CADs to make assimblies. Also it's tedious to use for 3d printing when you want to include modifier objects with your model. Otherwise it's great and good enough for part modeling

fogleman8• 7 months ago

It is kinda neat, but OpenSCAD's limitations are the main thing that motivated me to write this Python library to generate 3D meshes used signed distance functions:

https://github.com/fogleman/sdf

One big plus to doing it this way is that it's "just" Python and you can use arbitrary logic to help construct your model.

You can even load an existing 3D mesh and operate on it as an SDF. Great for hollowing, chopping, eroding/dilating, etc. existing models.

I should probably do more with this project. I think there's a lot of interest in this space.

JonathanRaines2• 7 months ago

I've used your library and really like it!

jandrese3• 7 months ago

You can even load an existing 3D mesh and operate on it as an SDF. Great for hollowing, chopping, eroding/dilating, etc. existing models.

This has my instant interest. Multiple times I have wanted to take an existing .STL file and cut a hole on it or add another object to it and have never had success.

I've tried things like Meshlab, but while the interface has what appears to be a hundred different functions, attempting to use anything returns some error code that requires a PhD to understand and none of the "repair" functions seem to help.

I mean seriously: Mesh inputs must induce a piecewise constant winding number field.

How the hell am I supposed to accomplish that on a STL file?

kesor• 7 months ago

OpenSCAD can load STLs and cut holes in them.

fogleman8• 7 months ago

That feature requires getting pyopenvdb installed, which can be a headache, and I never really updated the README with examples, but it does work. There is one example script:

https://github.com/fogleman/sdf/blob/main/examples/mesh.py

You basically just say:

f = Mesh.from_file(path).sdf(voxel_size=0.25, half_width=1)

Then you can operate on `f`.

dekhn• 7 months ago

Blender also has a high learning curve but you typically don't need a PhD to understand the errors (instead you just watch youtube videos and copy what they do).

Removing faces from an STL and adding other objects is quite straightforward. Previously, Autodesk had Meshmixer and 123D, I guess Meshmixer is still available: https://meshmixer.org/ and I found it to be great for quick editing of the type you're describing.

btbuildem• 7 months ago

Tinkercad is a very low-barrier-to-entry option here

Brian_K_White3• 7 months ago

You can do that effortlessly right in openscad itself or in freecad for a more visual way, or in every single cad app in existence I think.

In freecad you first just open the stl file, then Part -> Create part from mesh, then you have a solid you can modify.

fainpul2• 7 months ago

People should share the original files or at least step files along with the stl files. But if you must work with stl, Fusion works brilliantly for this. You can open the stl file, which gives you the usual mesh that's hard to work with. You then convert that mesh to a solid object, on which you can use "direct modeling". It's not the same as a parametric object, but the editing features are quite powerful and sort of mindblowing. [1]

If you have the paid version of Fusion, you can run "feature detection" to turn things like holes, fillets, extrusions etc. into dedicated features which are even easier to edit. [2]

[1] https://www.autodesk.com/learn/ondemand/curated/direct-model...

[2] https://www.autodesk.com/learn/ondemand/curated/direct-model...

yaky• 7 months ago

If it's a one-time thing, Prusa Slicer (and some other slicers too, probably) allow adding and subtracting simple shapes. So if, for example, you need to add a hole for a screw, you can do it directly in the slicer without messing with (and breaking the mesh of) an STL.

vhanda• 7 months ago

Could you please elaborate on how this is different than the other python based modeling tools - build123d[0] and CadQuery[1].

I recently also got annoyed with OpenSCAD and its limitations and therefore started experimenting with Build123d. I'm very much a beginner in the CAD space and would love to understand what inspired you to build sdf.

My basic understanding is that STL files are essentially like Bitmap images and store a list of triangles and their positions, whereas STEP files are more like Vector art where there is a list of instructions on how to build the model. Most CAD GUI programs also operate on a similar model to vector art where they record a list of operations one on top of another. It's why STEP files are a standardized format and can be imported / exported from most GUI based CAD builders. I think.

Given that SDF also seems like it builds only STL files (I could be wrong), wouldn't learning build123d or CadQuery work better if one cares about compatibility with existing GUI based CAD modeling software?

Additionally, atleast build123d offers a similar conceptual model to using Fusion360 and FreeCad - I have limited experience here - but essentially you sketch something in 2D on a particular plane, and then apply some operations to convert it to 3d in a particular manner - the simplest being extruding. This means the mental modeling of how to construct something is very similar across both GUI based CAD programs and Build123d, and that makes it easier for me to jump between GUI based and code based CAD modelling.

I'd love to understand your point of view, and learn more.

[0] https://github.com/gumyr/build123d

[1] https://github.com/CadQuery/cadquery

fogleman8• 7 months ago

It seems like you already understand the differences. I wasn't aware of those other projects. build123d looks pretty neat.

Like most of my projects, this was just for fun and I mainly made it for myself. I'm a DIY kind of guy when it comes to software. I just throw things up on GitHub in case anyone else can get some use or inspiration out of it.

zimpenfish• 7 months ago

Bless you for your service, sir! I have used `sdf` to create a whole bunch of stuff (buttons for my mother, tealight holders, etc.) and `gg` gets used in a bunch of places (including a couple of bots).

I should probably do more with this project.

I, for one, would be glad.

FeepingCreature2• 7 months ago

See also my site fncad https://fncad.github.io ! It's basically intended as "SDFs in your browser with realtime preview with openscad-like syntax". I mostly use it for 3d models for printing.

What do you use for sdf meshing? I never really got the perf where I wanted it.

fogleman8• 7 months ago

It's explained in the README. The SDF is evaluated on whole batches of points (32x32x32 tiles by default) using numpy. (And it's multithreaded.)

ur-whale5• 7 months ago

SDFs are very neat up until the point where you need to build parts that have very precise specifications.

Something like two precisely interlocking gears with a tooth geometry with a profile that's the developed curve of the opposite tooth is a nightmare to build with SDFs

Or precise fillets.

Or hard intersections and differences.

Very useful for doing soft, squishy shapes, less so for hard CAD.

Also, a suggestion: in your project, please consider using Wavefront OBJ as an output format, it is a much, much better choice than STL (STL can't represent the actual topology of the object, it has to be reconstructed).

userbinator• 7 months ago

From what I know, SDFs were popularised by the demoscene; it's interesting that they've now found more practical applications as a result.

mkl• 7 months ago

They long pre-date the demoscene, going back centuries in mathematics. Ray tracing/casting of implicit surfaces (described with SDFs and more general signed functions) for computer graphics goes back to the 1960s and 70s. The 1990s demoscene 2D metaball effects were based on computer graphics work by Jim Blinn for Cosmos in 1980. Most current applications are based on that long ongoing research. (I did my PhD in implicit surface stuff, so I've seen tons of academic papers on it going back ages, and I never ran into demoscene methods in that context.)

mosura• 7 months ago

This is brilliant. The ability to do blobby/metaball style blends so easily is a big benefit.

WillAdams29• 7 months ago

Interestingly, PythonSCAD has support for SDF by way of libfive:

https://pythonscad.org/examples.php

(search for "sdf" about halfway down the page)

the_cat_kittles• 7 months ago

maybe this will finally be the solution to my tapered variable pitch helix woes. it looks cool, thanks

jacquesm2• 7 months ago

It is amazing. I spend more time in OpenSCAD than in any other program I use and I'm amazingly productive with it. 3 to 4 cycles / day, the longest time is waiting for the printer to cough up the next iteration, then it is building debugging and improving again.

The power of parametric cad is such that I wouldn't be a 10th as productive using an interactive cad system. And because it is effectively software you are writing (even if it compiles into physical objects) you can use all of the goodies that you can use to manage software. Diff files, git, kompare, branching, merging. It is nothing short of amazing, it is like I have a design team and a prototype injection molding facility in one. And the turnaround time is something you'd have killed for in the 90's.

echoangle• 7 months ago

The power of parametric cad is such that I wouldn't be a 10th as productive using an interactive cad system.

This sounds like parametric and interactive CAD are polar opposites. Normal CAD software is generally parametric too.

The other points about the advantage of text files still applies though.

jacquesm2• 7 months ago

'Normal' cad software is parametric in an entirely different sense. You don't normally build up from entities just like you would in software, which you can then manipulate symbolically.

There are cad packages that can do this but unlike OpenSCAD the main interaction there is the 3D window, not the text editor.

Though AutoCAD of course had this with AutoLISP since 1986.

Interestingly, I'm not sure which has the steeper learning curve, OpenSCAD or AutoLISP. OpenSCAD is really great once it clicks but most people give up long before then.

arjie2• 7 months ago

Oh I had no idea that OpenSCAD was a programmatic toolkit. I recently bought a 3D printer and I don't model so much as describe to Claude Code how to write a Python script that will generate the required STL that I then rescale or whatever in Bambu Studio. LLMs are great at code-oriented stuff so I've stayed away from traditional modeling tools because I assumed you'd have to point and click and so on and I don't really want to learn the ins and outs of their interface. I just need the right mesh made.

The chatbots kept recommending I try using OpenSCAD but I resisted without even giving it a look. The results I had with just the Python script are quite adequate for the tasks I had. You can just ask the LLM to add a fillet to a vertical pin on a plane or to chamfer some edge and it is pretty good at doing it.

https://wiki.roshangeorge.dev/w/Blog/2025-12-01/Grounding_Yo... if you want to roughly see the workflow.

I'm going to try using OpenSCAD for things in the future. Does anyone else use exclusively an LLM with OpenSCAD (I used Claude Code and Codex) and if you do what did you do to make it more effective? The Python script wouldn't always generate printable meshes so I had to give it a check script to operate on.

ThrowawayTestr2• 7 months ago

Fusion 360 is free for hobbyists and it's not too hard to learn for basic stuff

arjie2• 7 months ago

Maybe I should suck it up and just give it a crack. Thank you for the recommendation.

avmich3• 7 months ago

Is it online only? I in general prefer locally installed software, without Internet requirements.

dvh• 7 months ago

I rage-quited every other CAD program. Then I found OpenSCAD. Now I'm looking forward to work in it every time I need to do some 3d modeling (usually new part model for kicad or some other project).

moebrowne3• 7 months ago

I had the same experience. I think OpenSCAD is ideal for people with a 'developer' brain.

As it happens I wrote about this almost exactly a year ago

https://mountainofcode.co.uk/3d-modeling-for-developers

exasperaited11• 7 months ago

Neat-ish.

I don't really see why that code is better, more logical, more readable or more robust than the equivalent quite trivial parametrics in more or less any GUI CAD program, and I think the geek discourse is really harmed by people who don't understand the value of the things that OpenSCAD can't ever offer.

avmich3• 7 months ago

I wonder what kind of things OpenSCAD can't ever offer... It's pretty automatable.

exasperaited11• 7 months ago

The main thing it cannot ever offer is the ability to further process its own generated geometry. It has no concept of edges, vertices or faces in 3D so you cannot do operations on them, which means no generalised operations like fillets or chamfers, only specific implementations for specific shapes.

This difference is profound, is the point I am getting at.

It also lacks any concept of constraints or constraint solving in 2D sketches, which makes some quite simple shapes extremely difficult to make without advanced maths.

So in both cases you never get away from the maths, and the maths complexity increases as your design complexity increases. You can see this reflected in the complexity of any large OpenSCAD codebase and in the number of functions in any large utility library.

CAD software should aid design. That’s its entire purpose. OpenSCAD just lets you plot 3D shapes and do some very limited operations to combine them.

haberman• 7 months ago

A long time ago I read that CadQuery has a fundamentally more powerful geometry kernel than OpenSCAD, so I dropped any attempt to try OpenSCAD.

Years later, I never actually got the hang of CadQuery, and I'm wondering if it was a mistake to write off OpenSCAD.

I am pretty new to CAD, so I don't actually know when I would run into OpenSCAD's limitations.

WillAdams29• 7 months ago

The notable limitations for OpenSCAD are:

- functional programming model --- some folks find not having traditionally mutable variables limiting

- output is as an STL, or DXF using polylines

- native objects are spheres, cylinders, cubes, with functions for hull and Minkowski, so filleting and other traditional CAD operations can be difficult

gunalx• 7 months ago

Once had a complex model that would fully crash and lockup fusion, but once redone in openscad rendered after a little while. (badly designed + slow pc at tye time)

tylervigen• 7 months ago

I’ve used OpenSCAD for 3D printing random objects for years. It’s the perfect tool for designing super simple geometric objects, because it giant demands that you remember hardly anything about his the interface works. Contrast with Fusion 360 or any other more powerful tool, which are fantastic if you use them daily but a slog of you only boot them up a few times a year.

Also with OpenSCAD, you can feed the documentation to your favorite LLM and ask it for a starter design of whatever you are building. (Or you can skip the documentation; it is in the trading data after all.) Maybe in the future that SVG Pelican on a bike test will be a 3D model in OpenSCAD.

rcarmo2• 7 months ago

Ooh, an LLM that could take requests for custom Gridfinity bins would be a good step towards AGI indeed.

WillAdams29• 7 months ago

This is being done for photographic inputs for shapes --- I believe at least one of these tools does that:

https://www.shapescan.pt/

https://www.tooltrace.ai/

lorenzohess• 7 months ago

That let() {} expression seems pretty similar to the LISP let()() form: https://lisp-lang.org/learn/variables

mcv2• 7 months ago

There's a tutorial? Maybe I should have started there.

I recently started messing around with OpenSCAD too. I found these boxes that are great for storing the tiles for various 18xx railroad boardgames: https://www.printables.com/model/287297-parametric-18xx-tile...

Cool thing is that you can easily print them in whichever size you like, and the sizes in the supplied files are rather large, so I tried some smaller sizes, and discovered some details weren't actually centered properly, so I dove into the code, tweaking some bits here and there until I got it centered properly.

Then my dad asked me to print boxes for a game that had slightly larger tiles, so I needed to tweak the sizes, the thickness, and made everything just a bit more configurable.

I've got another idea I haven't tried yet: print the shape of the track on the tile on the spot its meant for. That's a whole new feature and not merely tweaking an existing one, so maybe it's time to finally learn how this format actually works.

Although I did see in the code that you create shapes through intersections and substractions with other shapes. And that's where I got stuck. Maybe it's time to pick it up again. It's a fun way of building shapes.

WillAdams29• 7 months ago

For my part, when I have to rough out a design in OpenSCAD, I'll often use:

https://www.blockscad3d.com/editor/

mcv2• 7 months ago

That is really awesome. Thanks!

And not just for me; now I might also be able to get my kids to design stuff to print.

rcarmo2• 7 months ago

I’ve been using it for almost a decade and I still miss proper fillets and chamfers (and yes, I know the usual tricks).

Brian_K_White3• 7 months ago

It's a lot of work to make models that are useful in real life, but for some things it's worth it because it's sooo nice having 2k of plain text that describes an entire object, and it's even fully parametric, and it even comes with a customizer panel for the parameters, so every model isn't just a model, it's a model generator app, and even has meaningful diffs in git.

The same model in freecad is like 6 megs of zipped xml and realistically not nearly as usefully parametric.

That couple-k of plain text is such a huge deal that it makes all the other difficulty worth it for mechanical/functional stuff.

dheera• 7 months ago

OpenSCAD is the only CAD tool I use. I can'd figure out how to operate a graphical 3D software with a 2D GUI so it's just easier to describe things mathematically.

I just wish it had operations for subtractively chamfering, rounding, etc. as doing minkowski() with cones and spheres to achieve that result can be unwieldy.

derkades• 7 months ago

Do you know about BOSL2? It can do rounding or chamfering very easily.

cuboid([20, 20, 30], chamfer=5);

Brian_K_White3• 7 months ago

A few years ago I made a little module rounded_cube that generates a cube by drawing 1/8 spheres wrapped in hull, andnsince then I've been using that for everything, making inside fillets by using a rounded cube as a cut shape. Since it can generate a hollow box with a desired wall thickness, you have the shell of an enclosure box in a single call.

Over time I added other things like a single linear fillet, a single radial fillet, both interior and exterior, convenience things built out of those like a screw post with a fillet base etc. But really I always end up just using mirror_copy and rounded_cube a lot.

There is a scifi book series aboit a programmer who gets zapped into a fantasy world that has magic, and he becomes the most powerful wizard in the world because he applies the coding concept of reusable components and building big things out of smaller things and automation, which none of the other wizards ever thought of.

openscad is like that. To get anywhere you first have to build a library of useful higher level things out of the low level things. Like forth or assembly, or really all programming I guess.

bb88• 7 months ago

I find that I'm often making one-offs. I take a part I designed and I need a slight modification for it for some reason.

Fusion is great for that as long as there's not too many parts. But sometimes I'll want a new variant or a series of new variants.

And reaching for python makes that easy.

ur-whale5• 7 months ago

OpenSCAD is kinda of neat, especially if you pair it with something like codex to build objects.

And then, you discover that those darn LLMs have absolutely no spatial intuition. None.

It is seriously frustrating: one the one hand you can just feel the raw potential of vibe coding complex geometries, and on the other, when you do, you keep seeing the agent making mistakes a 5 year old playing lego would never make.

Absolutely infuriating.

ur-whale5• 7 months ago

OpenSCAD is great, and I use it all the time.Especially these days if you combine it with an LLM agent like codex and start vibe coding objects (see my other post on this).

However, there are a number of limitations that are truly and deeply frustrating.

1. The language is downright weird. Don't get me wrong, it's a very nice little exercise in implementing a functional-tasting scripting language. Someone obviously wanted to scratch a functional DSL design itch and he did, but the result is unfortunately extremely limiting. Creating a function that does not return geometry is barely possible (only bloody lambdas IIRC). He should have picked python instead (and yes, I know about SolidPython2)

2. From my POV: the main headache with OpenSCAD is there is no way to partially evaluate an object and use the result of that partial evaluation in the rest of the construction. For example, if you try to take two complex assemblies and place them tangent to one another ... very good luck to you sir, I pray and hope the 3D math is really strong with you.

Whereas: if you had a simple rayIntersect(csg_tree, line_in_3d_spce) that would return the first intersection and two normals ... something you can reuse in subsequent transforms and construction, man would life be simpler.

These days, with LLMs you can sort of build a scaffolding to work around this by asking the agent to break down the assembly in multiple stages and use external libraries to do the partial eval for you, but ... ugh ... what a mess.

3. Speed. The moment your CSG assembly gets complex (e.g. uses a ton of morpho ... hull, minkowski, etc...), OpenSCAD crawls to a halt.

4. NO FILLETS. The age-old, standard methodology of building things CSG style with cubes, spheres, cylinders, etc ... and then once the object is finished adding the rounding ... simply not possible with OpenSCAD. Adding fillets after the fact once you've built a complex CSG tree ... nightmare with OpenSCAD.

So, YMMV, but caveat emptor, if you get serious with the toole, you're bound to hit some very hard walls.

WillAdams29• 7 months ago

For a different language choice see:

https://pythonscad.org/

VerifiedReports• 7 months ago

Anything that helps people shun Autodesk's despicable, anti-customer and anti-industry practices is laudable.

iamwil• 7 months ago

Ah OpenSCAD. I wrote a tutorial a long time ago about the 10 things you need to know to get started.

https://cubehero.com/2013/11/19/know-only-10-things-to-be-da...

vjvjvjvjghv• 7 months ago

It’s pretty neat but for my taste the language is too functional. I don’t think a purely functional paradigm works well with CAD parts and the way they are constructed. The language gets in the way. Debugging complex parts is also quite difficult from my experience. But with some better tooling I think it could be absolutely great.

WillAdams29• 7 months ago

Well, there is a Python option now:

https://pythonscad.org/

jdranczewski• 7 months ago

An interesting use case of OpenSCAD is open source hardware with many contributors - the reasoning being that we only have mature version control tooling for text-based files (say git), and so your CAD design should be text-based. I was introduced to this idea by https://openflexure.org/projects/microscope/ - they managed to build a fairly complex 3D printed microscope project on this principle.

I'm aware of Onshape having a git-like workflow as well, wonder how the two compare! A fully cloud-based suite would probably not work well for an open source project.

WillAdams29• 7 months ago

Yeah, I wish that this had been popularized in the Maker movement, but Autodesk nuked that field when they made Fusion 360 "free" (which was probably their intent).

Joel_Mckay2• 7 months ago

OpenSCAD is great if you follow a subtractive workflow. Define simple stock geometry, and subtract away each feature with slightly wider primitives to avoid zero thickness intersections. This ensures you will not get weird bugs later, and a fairly accurate part for plastic printers.

As many correctly pointed out, STL & DXF are not considered professional file-formats anymore by some people. Some fabricators will not respond to quote requests, as without a Step file they are literately self-confessed useless clowns without Onshape/Fusion true solids handling the ugly math.

It is partially a unofficial standards issue, but customers without Step files may have to look around for fabricators. YMMV =3

imtringued• 7 months ago

STL is not used outside of 3d printing for obvious reasons.

STLs have an obvious quality problem with geometry since they have an internal resolution that cannot be changed. The amount of people printing STL artifacts into their plastic parts is kind of ridiculous, honestly speaking.

The other problem is that CNC machines turn the geometry encoded by STEP files into toolpaths. This is basically impossible with meshes unless you want to mill the STL artifacts right into your part with a generic tool.

In subtractive manufacturing the manufacturer has to choose a selection of tools and assign each tool to the relevant features of the part. If you want holes you need a drill, if you want threads you need a tap, if you want fillets or chamfers, there is a tool for that and so on.

Your STL file is the equivalent of a JPEG here. It has already lost the critical information that is needed to manufacture your part.

Joel_Mckay2• 7 months ago

The STL file literally means Stereolithography, and was created by 3D Systems. It is the intended use-case, and is limited like any other file format.

The fact many fabs avoid DXF is unit and format version ambiguity. However, the other reason is predicting bend deduction is often wishful thinking. Most high end CAD packages are fairly good at handling that mess for people, but often still have issues figuring out how features will deform.

CAD can also start to fail on large complex geometries, as even a simple single combo-tool g-code macro to drill, helical mill, and chamfer threaded-holes in a plate often is done by the time CAD/CAM path-planners finish/crash.

Best of luck =3

thdrtol• 7 months ago

Tip (a lot of people don't know this): you can set the resolution by setting the $fn variable. This can be useful when you want to export smooth objects.

  $fn = $preview ? 32 : 64;

voxleone2• 7 months ago

Just a minor aside: When exporting geometry for FEM, you generally should not make $fn very high (values around 32–64 are usually fine). High $fn improves visual smoothness, but it often hurts FEM meshing and solver performance without improving accuracy, since FEM accuracy is governed by the solver’s mesh rather than the CAD tessellation.

givc• 7 months ago

I found that combining OpenSCAD with SVGs for extruding complex shapes is quite powerful. I made a map of Manhattan that could not be handled by any other CAD program I tried without crashing, but OpenSCAD handled it really well.

I wrote more about it here, although I only mentioned OpenSCAD briefly https://hackaday.io/project/202488-manhattan-subway-map/deta...

typesafeJ• 7 months ago

I created a simple go library to output OpenSCAD code a few years ago. https://github.com/richi0/gocad

yoan9224• 7 months ago

OpenSCAD is perfect for the "programmer's brain" approach to CAD. Being able to parametrize everything means I can design something like a project enclosure once, then generate variants for different screen sizes or component layouts by just changing a few variables.

Pro tip: Use the latest nightly build and switch to the Manifold backend in preferences. Render times drop from minutes to seconds for complex models. The official 2021 release is painfully outdated.

Also, the BOSL2 library is essential - it adds proper filleting, rounding, and attachment operations that vanilla OpenSCAD lacks. Makes the difference between toy projects and actually useful designs.

The Git-friendliness is underrated too. Diffing .scad files is trivial compared to trying to understand what changed in a binary Fusion 360 file.

s0rce• 7 months ago

hmm, I didn't know about the BOSL2, I was struggling with fillets and chamfers, you basically had to figure out how to define them somehow which isn't really straightforward. Been using FreeCAD mostly which still has weird issues with fillets sometimes.

benbojangles• 7 months ago

I like openscad it allowed me to create a shed generator which also provides material quantity output, so an accurate shopping list is created - all done in code super impressed. I could not figure out how to do the same thing in standard cad software.

moebrowne3• 7 months ago

You don't have to use their editor either, there is a whole list of alternative editor plugins.

OpenSCAD can automatically re-render a preview as soon as the external editor saves to disk

https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_an_...

gmiller1234562• 7 months ago

I really wish OpenSCAD had objects, so you could use something like box1.width rather than having to declare variables for such things.

I tried using Build123d, a Python library that lets you use all of the features of Python. And it's supposed to allow specifically things like box1.width, but it's always 0. Lots of other issues/bugs too, and severely lacking in ddocumentation.Maybe it'll get there some day.

revision17• 7 months ago

Maybe it's improved since I last used it (seems to still be an issue per a 1 minute google search), but OpenSCAD doesn't really have easy support for dimensioned drawings.

While it was very handy for my programmer brain to create a few 3D printed things, when I wanted to create a drawing for something I'd make myself, adding dimensions seemed very unwieldly. I used a different CAD program for those projects (maybe Autodesk Inventor?).

nayuki• 7 months ago

One part that confused me is how I needed to use let() to define startColumn and startRow inside the loop. I don’t understand this…

That's because you wrote a for-loop without braces, so it can only contain a single statement, and that single statement is your let().

Here is an equivalent way to write that section of code (and I did test it):

    for (r = [ 1 : numRows ]) {
        startColumn = ((c * thicknessWall) + ((c - 1) * batteryType));
        startRow = ((r * thicknessWall) + ((r - 1) * batteryType));
        translate([startColumn, startRow, thicknessWall])
            cube([batteryType, batteryType, heightCompartment + 1]);
    }

Side note, related to declaring variables but not an issue that you encountered: OpenSCAD does not allow setting the value of a variable more than once. So this code is illegal:

    x = 1;
    echo(x);
    x = 2;
    echo(x);

Second note is that whenever you introduce a construct such as {union(), difference(), if(), for()}, variables declared within the braces are scoped, so they don't exist between iterations or after the scope ends.

    if (true) { y = -1; }
    echo(y);  // Illegal

However, just introducing braces without a construct does not restrict the variable to the scope:

    { z = 5; }
    echo(z);  // Legal

platevoltage• 7 months ago

I love it. It's really the only 3d modeling that I know to do. I've been enjoying it more after setting up VSCode as the editor.

gsohler• 7 months ago

Did you try your library with PythonsSCAD.org ? You can view your results right there and PythonsSCAD also has an onboard sdf (libfive) engine.

OpenSCAD is kinda neat

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