Some CAnn3D models I build!

[sgenoud]

Hei,

I have built a small layer on top of opencascade.js (that feels a bit like cadquery). It is not public yet, but it allowed me to build some nice models (that I called CAnn3D, because they are canned 3D CAD models).

First, a box for decks of cards (which is part of a set of tools to create boxes for boardgames).

I also documented some models on my blog a gym arch and corners to stack boxes

And also a customisable vase and another one. As well a a generic hanger hook

Would there be an interest in my (higher level that raw occt) library as well?

Generally thanks @donalffons for this great way to use opencascade!

[Irev-Dev]

Nice,

Have you seen CascadeStudio @sgenoud? Is you lib similar?

[sgenoud]

Yes, actually I found out about opencascade via cascade studio. I really liked it but there was a couple of things that did not fit with what I wanted to do:

• it is a complete environment and not just a library. CascadeStudio standard library is nice, but not easy to integrate in another project. For instance, putting it in a tool like deckinabox was not obvious. Or even including it as an iframe in blog post.
• I like to write my code in Neovim (yeah, I know this is not that important)
• I needed another way to select edges (or faces) for fillet for instance. I found the index very frustrating to use (especially because it is not topological and can change while iterating in a design

That said, a variant of CascadeStudio with my library (instead of its standard library) would be totally possible!

[sgenoud]

As an exemple of what the code looks like, this is the simple vase code:

const buildVase = (  {
    height,
    baseWidth,
    wallThickness,
    lowerCirclPosition,
    lowerCircleRadius,
    higherCircleRadius,
    higherCirclePosition,
    topRadius,
    topFillet,
    bottomHeavy,
  }
) => {

  const splinesConfig = [
    { position: lowerCirclPosition, radius: lowerCircleRadius },
    {
      position: higherCirclePosition,
      radius: higherCircleRadius,
      startFactor: bottomHeavy ? 3 : 1,
    },
    { position: 1, radius: topRadius, startFactor: bottomHeavy ? 3 : 1 },
  ];

  const sketchVaseProfile = new Sketcher("XZ")
    .movePointer(0, 0)
    .hLine(baseWidth);

  splinesConfig.forEach(({ position, radius, startFactor, endFactor }) => {
    sketchVaseProfile.smoothSplineTo([baseWidth * radius, height * position], {
      deviation: [0, 1],
      startFactor,
      endFactor,
    });
  });

  let vase = sketchVaseProfile.lineTo(0, height).close({
    returnType: "revolutionSolid",
  });

  if (wallThickness) {
    vase = vase.shell({
      filter: new FaceFinder().containsPoint([0, 0, height]),
      thickness: wallThickness,
    });
  }

  if (topFillet) {
    vase = vase.fillet({
      filter: new EdgeFinder().inPlane("XY", height),
      radius: wallThickness / 3,
    });
  }

  return vase;
}

[Irev-Dev]

Very interesting,

I really do like the the idea of a higher level lib built on top of opencascade.js, if for nothing more than it being brep but also to escape the CSG mindset of other code-CAD libs. I agree with your comments about CascadeStudio, I really like the project, but definitely a few things I would have done differently (running outside of the browser is important imo)

[donalffons]

That's beautiful! 🙂 Great showcase and the applications feel very well made. And the fact that you're using React-Three-Fiber and Leva make me feel at home 😉.

Some ideas regarding libraries in general:

• I would love to see libraries around opencascade.js. As we all know, OpenCascade tends to be very verbose and can be quite complex. In the same time, there seems to be a lack of resources that can teach users how to use the library effectively.
• I don't think that a library should aim at completely abstracting away opencascade.js. Ideally I would like to be able to compose different libraries inside one opencascade.js application. That also means that the initialization of opencascade.js should not be part of the library.
• I think libraries should try to focus on certain aspects. Having a "scattered" library to do various unrelated things might not be a good way to go.
• Libraries should be published as NPM-packages, so that they can be easily integrated into user's projects.
• Libraries should follow common "best practives", i.e. be tree-shakeable, shouldn't mutate prototypes and ideally come as JavaScript with .d.ts type definitions.

I've lately also been thinking on the topic of IDE's... I think it would be fantastic if there was a way to combine the powers of a real browser based IDE like Stackblitz (including the ability to install libraries via npm or unpkg) and a CAD editor like CascadeStudio. But this might not be an easy thing to pull off... In case @zalo has thought about this before, it would be great to hear your thoughts.

[sgenoud]

Where do you think the memory management should be done. In a library or in opencascade.js?

It seems that having the library do the garbage collection seems cleaner. It should do some of it anyway, and having a shared responsibility does not feel right.

[donalffons]

Hmm, good question. I think you're right - the library should be responsible for cleaning up everything that is considered "temporary".

Of course, if the library returns (for example) a TopoDS_Shape to the user, the user then "owns" that object and the library can no longer be responsible for cleaning that up.

[zalo]

There's not a bad argument to be made for making CascadeStudio into an extension for VS Code.

As long as it adheres to this format, then local online instances of VSCode (like https://github.dev/ ) should be able to hold the model rendering window alongside the code inside the IDE.

That way, you'd get to reap the ecosystem benefits of VS Code (native Github version control, other extensions, npm packages(?) etc.) without having to sacrifice local execution like Stackblitz might require... It might also simplify the codebase a tiny bit... but I'd be sad about losing 1-click browser model sharing and the loss of accessibility (locking modelling behind VS Code and an extension installation).

[timbod7]

@sgenoud this looks really nice. Do you plan to share your library?

[promontis]

@sgenoud Sounds great! Do you have an estimate on when you can publish the repo (hopefully soon)? Also, could you add a sponsor button? I'm sponsoring some other open source projects as well that I find cool and this is definitely one! Not too much btw (like $10 p/m), I'm no big company or anything like that.

This does not seem to be documented in cad query yet, is it?

The PR has already some docs in it.

[sgenoud]

I realise that I have forgotten to mention here that my library based on opencascadejs, replicad is published: https://replicad.xyz/

[zalo]

Very nice; I like your Sketching and Finder abstractions!

[donalffons]

This is fantastic! Congratulations on that library and the excellent documentation.
Think about requesting your project to be listed here 🙂.

Are you considering to release this as an NPM library, too?!

[sgenoud]

It is already on npm! (the opencascade custom build as well, but it should work with the standard one as well)