Show HN: Geomatic – A command-driven geometry studio enabled with autodiff

https://www.tinyvolt.com/geomatic
All commands have the format `output = \func inputs` or just `\function inputs`. Points and scalars are built on the fly. Eg `\line a b` to an empty canvas creates points `a` and `b`, and joins them with a line.

One can use broadcasting semantics similar to NumPy and PyTorch in a visual setting (imagine creating a list of circles where one dim corresponds to radius and another to the center). One can also use backpropagation, run gradient descent or visualize vector fields. Almost everything is reactive so changing a variable updates all of the downstream geometry. It also allows anyone to write and load their own visualization, which can be broadcasted and differentiated through.

https://www.tinyvolt.com/geomatic/examples/getting-started

Comments

sowowMay 25, 2026, 9:02 AM
I liked this one, but it took me a while to understand, I think this page is a much better intro: https://www.tinyvolt.com/geomatic/examples/getting-started
dangMay 25, 2026, 9:51 PM
We've added that link to the toptext too. Thanks!
felooboolooombaMay 25, 2026, 9:37 AM
Bug: https://www.tinyvolt.com/geomatic/examples/broadcasting-in-g... Click "Draw a single n-star" Results in a message popping up "unknown command: n-star"
galaxy_questMay 25, 2026, 12:20 PM
You have to load the extension, the instructions are in the text above the button.
hbwang2076May 25, 2026, 9:56 AM
Clean implementation. One thing I always look for: how does this degrade when things go wrong? Good error handling is what separates weekend projects from tools people actually use.
james_marksMay 25, 2026, 3:57 PM
As an adult, I now write clean error handling first thing.

The person it benefits the most is the author, when they are building it and the errors-per-use are as high as they’ll (hopefully) ever be.

dmos62May 25, 2026, 10:25 AM
Pretty cool. Curious, why a one time payment? Why not, say, a smaller monthly payment?
nivterMay 25, 2026, 3:05 PM
Not a fan of subscription hell myself, I plan to use one-time payment for all my products. Implementation wise one time payment is much simpler than setting up smaller payments that cap at a fixed amount.
sowowMay 25, 2026, 12:36 PM
Not OP, but for me personally I’m tired of subscriptions. I’m grabbing the one time payment before OP changes his mind.
herpdyderpMay 25, 2026, 3:54 PM
- When I have an example open, I can't type any commands.

- When I open an example, I expected to actually... see an example. I'm not gonna read the wall of text. I don't even understand what this is yet, that's why I tried to see an example.

necovekMay 26, 2026, 7:21 AM
The example was great for someone like me: I'd rather read through and follow excellent instructions by clicking through commands to understand the value of this command-driven tool.

If you want to look through a video or something, then this tool is likely not for you! (nothing bad with that, that's why it's great that there are so many different tools we can choose from)

roger_May 25, 2026, 12:43 PM
Cool idea but not very mobile friendly it seems.
ddxvMay 25, 2026, 8:25 AM
What is autodiff?
nivterMay 25, 2026, 8:29 AM
Automatic differentiation. For any DAG with a scalar output, it allows calculating its partial derivative wrt the input parameters.
RexxarMay 25, 2026, 3:48 PM
I don't understand what the use automatic differentiation for in this context.
nivterMay 26, 2026, 5:39 AM
Some use cases and examples are provided here: https://www.tinyvolt.com/blog/bringing-autodiff-to-geometry
candizdarMay 26, 2026, 7:00 AM
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dsecurity49May 25, 2026, 9:47 AM
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embirdatingMay 25, 2026, 10:02 AM
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ArmonsrerMay 25, 2026, 10:17 AM
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