Comment by antelocnova | Hacker News Reader

Comment by antelocnova | Hacker News Reader

Hi there :-)

New on HN, first time posting, and (I guess) my post on Show HN was rejected...

Anyway, I hope I'm not bothering anyone by posting this outside Show HN, or posting almost the same thing twice.

Past year, around December, I started experimenting with making ChatGPT and Claude generate source code in LDraw language.

This LDraw is literally an "assembly" language, a low-level programming language that describes how to assemble LEGO pieces together into models, one placement instruction at a time.

When executed by specific tools, like e.g. LDView, LeoCAD, Studio... these instructions become LEGO CAD models, that can be interacted with, modified, etc.

Or, in other words: one LDraw source file in .mpd or .ldr format is equivalent to one LEGO CAD model.

So, the idea I had was: if I manage for maybe ChatGPT or Claude to generate high-quality LDraw source files... then, they would actually be generating high-quality LEGO CAD models, right?

Then, after months of iterations and trying one thing after the other... it worked!!!

Long story short: using GPT-6 Astra and Opus 5.5, I've managed to create a python toolset, instructions, and docs for agents in general. Now, these can be used by them to generate LDraw models.

I've packed it all as a dockerized web app for others to try and experiment, with several providers (and agents) to choose from: OpenAI, Claude and OpenRouter.

I'd really appreciate feedback and comments, let's see where this goes =)

This project is perfect for a Show HN! I moved (most of) your text to the top and added "Show HN" to the title. I'll respond to this bit here:

> and (I guess) my post on Show HN was rejected... Anyway, I hope I'm not bothering anyone by posting this outside Show HN, or posting almost the same thing twice.

Unfortunately we had to put some barriers in place (https://news.ycombinator.com/showlim) because we got flooded, and still are, with Show HNs from new accounts which lack the spark of curiosity that is most important here. The hope is people will take the time to read the site, participate in threads, get a feel for the culture, and eventually post a Show HN that is a better fit.

None of that applies to your project, and if we had a better way to screen these things, we'd write software that let posts like yours through the first time. In any case I'm glad I randomly saw this one, and welcome to HN!

Thanks dang!

I really appreciate you helping me with this, and totally get the bit about getting flooded.

Anyway, I hope HN community will like this, and maybe contribute, have some crazy ideas about how and where to move forward =)

(Normally I'd email, but maybe it's fun for others to be in on the conversation.)

I think this post would be even better if there were more visual examples to look at. Would it be possible to link to more pictures, or even a demo video, showing different cool and/or weird things produced by the tool?

(In terms of video, you don't need anything fancy - what works best is raw and direct, with zero production values.)

Also, another thing that isn't clear to me is whether you've built any of these structures physically. If so, it would be particularly cool to see that in action! If not, it would be interesting to know what it would take to do so.

Well, here it is:

https://anteloc.github.io/index-samples.html

That's a gallery of by-products and results from different executions.

Videos, I'm afraid I don't have any, these CAD models can be better inspected by opening them on e.g. LDView, that to record LDView while playing with them.

Those come from opening ldraw-nova on VS Code, asking different coding agents (Codex, Claude Code, etc.) to read the instructions.md at the repo, and then to build something.

Also, from different attempts by different agents in order to learn "how" to do something, like e.g. place an axle correctly.

Those are just leftovers, usually images like those show embedded in web app chats on LDraw Nova.

If you are curious about the internals of an .mpd model, the "what was the agent picturing on its mind", open the .mpd file that got your attention on a text editor, and read the first line under the ones starting with "0 FILE".

Great - I've added https://anteloc.github.io/index-samples.html to the toptext, along with the last sentence of your comment here. I hope that's ok!

Sure! Thanks dang ;)

And regarding building those, well... actually, I didn't even try, the amount of parts required alone for the larger models is actually in the order of the thousands, my guess is it would be difficult to get all the required parts for just one of those models.

I'm currently considering 3D-printing a small one, however, in order to see how it looks IRL.

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