truck VS nomicon

I agree 100%.

Truck[1] and Fornjot[2] are recent attempts in the Rust space, both are WIP.

But both seem to be going the traditional way. I.e. B-Rep that can be converted to (trimmed) NURBS.

I think if one wanted to incorporate the last 50 years of computer science, particularly computer graphics, one needed to broaden the feature set considerably.

You need support for precision subdivision surface modeling with variable radius creases (either via reverse subdivision where you make sure the limit surface pass through given constraints or using an interpolating subivision scheme that but has the same perks as e.g. Catmull-Clark).

Then you need to have SDF modeling ofc.

Possibly point based representations. If only as inputs.

And traditional B-Rep.

Finally, the kernel should be able to go back and forth lossless between these representations wherever possible.

And everything must be node-based, like e.g. Houdini. Completely non-destructive.

[1] https://github.com/ricosjp/truck

[2] https://github.com/hannobraun/fornjot

I think you confuse the book/tutorial with the documentation on docs.rs.

My impression is that the former is very much a work in progress. I never looked at it until now.

The latter (and the examples in the resp. crates) is what you want to look at to see the kernel being used. E.g. https://github.com/ricosjp/truck/blob/master/truck-modeling/...

The main README has links to all the documentation of the crates.

There are two Rust projects working on parametric kernels I'm aware of.

The first one, Truck[1] seems to have a company behind it, Ricos Ltd, that look like they to know what they're doing[2]. The tweet shows their product using functionality from Truck (the frontend is not OSS AFAIK).

Fornjot is an ambitious project IMHO. Their kernel is in a separate crate[3].

As for OSS code that could be a good base to either use (or port to something like Rust) for someone to write their own kernel is Ayam [4], the oldest OSS 3D NURBS modeler that is still being developed.

[1] https://github.com/ricosjp/truck

[2] https://twitter.com/RICOS_ltd/status/1550390552482693120

[3] https://crates.io/crates/fj-kernel

[4] https://ayam.sourceforge.net/

I've been following your project with interest and was wondering if you were familiar with Truck. Its another project implementing a CAD kernel in Rust.

I will definitely keep reading and learning, as well as gaining practical implementation experience. We'll have to see how that goes, and what the solution will end up being.

> Another direction you could take is to define just the API, and use the opencascade kernel (like FreeCAD) until the rest of your code is ready.

A CAD kernel is the central dependency for any CAD program, and I feel that it would be wrong to just use one and accept its limitations. I need to be able to take ownership, to work on it directly. OpenCASCADE is a huge pile of C++ code, which is the opposite of all that. (Not saying it's wrong to use in general, just that I'm the wrong guy to work on a huge pile of C++ code.)

I've considered using Truck[1], but decided not to do that for now. I really want to see what I can come up with. If that doesn't work out, at least I'll be in a much better decision to decide what other option would be best.

[1] https://github.com/ricosjp/truck

For a specific example: I am interested in working with 3D objects using Rust (maybe this is too ambitious for a newbie!) so I found a CAD kernel crate called truck which seems to be crate built of smaller crates and implementations of other libraries. How would you go about finding the most relevant info and where to start? Should I start by understanding all the smaller parts such as the gui/gpu rendering modules, or is that irrelevant and I can focus on figuring out the top level?

it’s even written by the same person that wrote the Nomicon (the guide to the dark arts of unsafe)

If you want to dive deeper you can always have other options but now there are concrete cases, if you want to do low level thing https://doc.rust-lang.org/nomicon/ while if you want multi thread/concurrency stuff https://marabos.nl/atomics/ . There are many many books so you will have to point yourself to what you want

Nonononono. SeqCst is the most error prone memory order: https://github.com/rust-lang/nomicon/issues/166

Hope this helps. For more details, see the Rustonomicon. I referenced the subtyping chapter here extensively.

Nice video! Glad I could help out. This stuff is hard, and I'm still learning a lot about it myself even years later. The Rustonomicon is a great read if you haven't already.

Have you got a moment to read through the good book , after reading through this perhaps try the Rustonomicon.

That is not what UB means. Undefined Behaviour is behaviour that the compiler is allowed to assume will never happen, and which can consequently cause miscompilations due to optimisation passes gone wrong if it does in fact occur in the source code.

It's true that Rust does not have a written specification that clearly delineates what is and isn't UB in a single place. But:

1. UB is impossible in safe code (modulo bugs in unsafe code)

2. There are resources such as the Rustinomicon (https://doc.rust-lang.org/nomicon/) that provide a detailed guide on what is and isn't allowed in unsafe code.

In practice, it's much easier to avoid UB in Rust than it is in C++.

However, this is a wide topic out of scope for a Reddit comment, so maybe just read the Rustonomicon. It explains everything about data handling in Rust.

The ownership model & borrow checker makes rust a bit of an awkward language in which to write complex data structures like trees and graphs. It can be done - since you can always use raw pointers & unsafe code when you absolutely need to to treat rust like C. But the language fights you, and the community can get a bit moralistic about this sort of thing. The rust nomicon is a fantastic resource for learning the limits of the borrow checker, and where and how to use unsafe code correctly. You will need unsafe less than you think you will, but sometimes you will have no choice.