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CAD is a different beast than mesh modeling. For product design you need a parametric model that can have precise dimensions and is constructed mathematically s

by jrflo 11d ago

CAD is a different beast than mesh modeling. For product design you need a parametric model that can have precise dimensions and is constructed mathematically step by step. Mesh modeling is just moving a pile of triangles around in a very imprecise way. Works fine for 3D printing or digital assets, but if you want something that can be manufactured that's not good enough. And there isn't a good way to go from STL -> Parametric CAD so there's still room for a product here.

ur-whale 11d ago
> there isn't a good way to go from STL -> Parametric CAD yet. as a matter of fact, you should try what AI can do on that problem, you'd be surprised.
- jrflo 11d ago
  I have tried, I really wish it would be better because CAD is a slog and I want it to be automated. It's pretty bad at real world tasks.
ttul 11d ago
It's just a matter of time. Astra was trained on a new 3D modelling dataset. They will surely train it on CAD apps (if they have not already done so). I don't hold out much hope for competitors hoping to get in front of that train.
- deleted 11d ago
  [deleted]
yakz 11d ago
Astra can use build123d, too. You'll get a STEP out of that.
- jrflo 11d ago
  I've tried Sol on build123d and it was completely unusable, I should take another stab with Astra though.
  - ricketycricket 11d ago
    I had a similar experience, but it worked just well enough that I wanted to try my own similar experiment, but using a functional API in Elixir and giving the agent some introspection tools. I'm very much a novice to this space and learning as I go, but I've been able to make some interesting projects with the library so far, which is all I really want to do: https://smith.hexdocs.pm https://smith.hexdocs.pm If you want to build by hand, there is a Kino renderer to build your projects interactively in Livebook, which is actually surprisingly helpful for learning.
buildsjets 11d ago
CATIA has had mesh import with canonical feature detection, and automatic replacement with parametric part features, for at least 25 years. It's in the "Quick Surface Reconstruction" and "Basic Surface Recognition" tools. They even work sometimes. https://3dswym.3dexperience.3ds.com/wiki/catia-user-community/catia-quick-surface-reconstruction-2-qsr_61sQK1ZURYCZlFEbiThOtg https://3dswym.3dexperience.3ds.com/wiki/catia-user-communit... https://resources.rand3d.com/insights-from-within/scanned-data-in-catia-v5-an-intro-to-digitized-shape-editor-and-quick-surface-reconstruction https://resources.rand3d.com/insights-from-within/scanned-da... Unfortunately the P3 license costs like $15k per year, and it is f'in ugly clunky software.
prodmod 11d ago
I was able to have Astra accurately solid model with plasticity (NOT import from Blender) and presumably it would be trivial with autocad, but I haven’t tried it yet.
glaslong 11d ago
I suppose you might be able to force a Blender agent to do parametric modeling via geometry nodes. It would be a horrible, kludgy, slow workflow for a human, but the AI won't complain.
YuechenLi 11d ago
The only way to go from STL to BREP is through decompilation style recovery/reconstruction, because of the semantic information loss, so it's a task that can only be done via LLMs or human CAD users. Essentially, they pretty much have to remake the model from scratch using the STL as a reference to make the CAD. There really isn't a good way to automate this without machine learning/LLMs.
- dekhn 10d ago
  Fusion 360 can convert many STLs to BREP automatically. It can be slow and error prone but it does work. It will recognize large regularly curved areas and replace thousands of triangles with a single smooth curve.
fsloth 11d ago
" if you want something that can be manufactured that's not good enough" People design all sort of buildable things in SketchUp and it's just about dragging polygons around. You _may_ need accurate surface if you run your model to CAM. But to this day lot of manufacturing is still done via drawings and there the only thing that matters is that can you draw some type of lines and attach clear dimensions to them. So the shapes don't necessarily need to be accurate for all flows since they are more like topological hints to the person reading the drawing rather than accurate replica of the thing to manufacture.
- deleted 11d ago
  [deleted]

by jrflo 11d ago

ur-whale 11d ago

> there isn't a good way to go from STL -> Parametric CAD yet. as a matter of fact, you should try what AI can do on that problem, you'd be surprised.

jrflo 11d ago
I have tried, I really wish it would be better because CAD is a slog and I want it to be automated. It's pretty bad at real world tasks.

ttul 11d ago

It's just a matter of time. Astra was trained on a new 3D modelling dataset. They will surely train it on CAD apps (if they have not already done so). I don't hold out much hope for competitors hoping to get in front of that train.

deleted 11d ago
[deleted]

yakz 11d ago

Astra can use build123d, too. You'll get a STEP out of that.

jrflo 11d ago
I've tried Sol on build123d and it was completely unusable, I should take another stab with Astra though.
- ricketycricket 11d ago
  I had a similar experience, but it worked just well enough that I wanted to try my own similar experiment, but using a functional API in Elixir and giving the agent some introspection tools. I'm very much a novice to this space and learning as I go, but I've been able to make some interesting projects with the library so far, which is all I really want to do: https://smith.hexdocs.pm https://smith.hexdocs.pm If you want to build by hand, there is a Kino renderer to build your projects interactively in Livebook, which is actually surprisingly helpful for learning.

buildsjets 11d ago

CATIA has had mesh import with canonical feature detection, and automatic replacement with parametric part features, for at least 25 years. It's in the "Quick Surface Reconstruction" and "Basic Surface Recognition" tools. They even work sometimes. https://3dswym.3dexperience.3ds.com/wiki/catia-user-community/catia-quick-surface-reconstruction-2-qsr_61sQK1ZURYCZlFEbiThOtg https://3dswym.3dexperience.3ds.com/wiki/catia-user-communit... https://resources.rand3d.com/insights-from-within/scanned-data-in-catia-v5-an-intro-to-digitized-shape-editor-and-quick-surface-reconstruction https://resources.rand3d.com/insights-from-within/scanned-da... Unfortunately the P3 license costs like $15k per year, and it is f'in ugly clunky software.

prodmod 11d ago

I was able to have Astra accurately solid model with plasticity (NOT import from Blender) and presumably it would be trivial with autocad, but I haven’t tried it yet.

glaslong 11d ago

I suppose you might be able to force a Blender agent to do parametric modeling via geometry nodes. It would be a horrible, kludgy, slow workflow for a human, but the AI won't complain.

YuechenLi 11d ago

The only way to go from STL to BREP is through decompilation style recovery/reconstruction, because of the semantic information loss, so it's a task that can only be done via LLMs or human CAD users. Essentially, they pretty much have to remake the model from scratch using the STL as a reference to make the CAD. There really isn't a good way to automate this without machine learning/LLMs.

dekhn 10d ago
Fusion 360 can convert many STLs to BREP automatically. It can be slow and error prone but it does work. It will recognize large regularly curved areas and replace thousands of triangles with a single smooth curve.

fsloth 11d ago

" if you want something that can be manufactured that's not good enough" People design all sort of buildable things in SketchUp and it's just about dragging polygons around. You _may_ need accurate surface if you run your model to CAM. But to this day lot of manufacturing is still done via drawings and there the only thing that matters is that can you draw some type of lines and attach clear dimensions to them. So the shapes don't necessarily need to be accurate for all flows since they are more like topological hints to the person reading the drawing rather than accurate replica of the thing to manufacture.

deleted 11d ago
[deleted]