dfdx VS rapier

I keep checking the progress on dfdx for this reason. It does what I (and, I assume from context, you) want: Provides static checking of tensor shapes. Which is fantastic. Not quite as much inference as I'd like but I love getting compile-time errors that I forgot to transpose before a matmul.

It depends on the generic_const_exprs feature which is still, to quote, "highly experimental":

https://github.com/rust-lang/rust/issues/76560

Definitely not for production use, but it gives a flavor for where things can head in the medium term, and it's .. it's nice. You could imagine future type support allowing even more inference for some intermediate shapes, of course, but even what it has now is really nice. Like this cute little convnet example:

https://github.com/coreylowman/dfdx/blob/main/examples/night...

And for transformers, it's really early days for dfdx, but it's a library that aims to sit basically at the Pytorch level of abstraction, that the difference is it's not just coded in Rust, but it follows the Rust-y/functional-y philosophy of "if it compiles it runs".

Wow that is super interesting. I actually tried to use GATs at first to be generic over shapes, but I couldn't do it, I'm sure it would be possible in the future though. There is this library dfdx that does something similar to what you mentioned, but it feels a little clumsy to me.

Awesome, I added an issue here https://github.com/coreylowman/dfdx/issues/597. We can discuss more there! The first step will just be adding the device and implementing tensor creation methods for it.

The next release of dfdx includes a CUDA device and implements many ops. The same dev created a new crate, cudarc, for a wrapper around CUDA toolkit.

A question I have is: what are the philosophical/design differences with dfdx? As someone who's played around with dfdx and only skimmed the README of burn, it seems like dfdx leans into Rust's type system/type inference for compile time checking of as much as is possible to check at compile time. I wonder if you've gotten a chance to look at dfdx and would like to outline what you think the differences are. Thanks!

Ok, so this uses https://rapier.rs/ which is very cool

Rapier, alongside https://nalgebra.org/ (which it uses underneath) has seriously good documentation and some advanced features like cross-platform determinism (something made hard by the way floating point differs between platforms)

Code examples: see examples2d, examples3d-f64 and examples3d directories

What are the pros and cons compared to something like Rapier? When should one use Bevy XPBD instead of Rapier, or vice versa?

Still using Rust in a browser-based multiplayer party game I'm working on! I'm using Actix Web for the backend and rapier2d to handle my game's physics. I'm looking to make some more connections amongst the developer / gaming community through my game down the line.

I have noticed that Rapier 0.17 contains a RopeJoint struct, which constrains maximum distance between two dynamic bodies. It doesn't seem to have found its way into bevy_rapier3d yet so I haven't understood whether it supports (half of) my use case, and looking at the code (https://github.com/dimforge/rapier/blob/master/src/dynamics/joint/rope_joint.rs) I really cannot see how it is actually implemented and how I could extend it to also set a minimum distance, but this may be a place to start.

I was also frustrated with the kcc, so I opened a PR that fixes most of my issues: https://github.com/dimforge/rapier/pull/446

Likewise, see the js bindings of Rapier.

Maybe check out how Rapier does it. Rapier is likely the most advanced physics engine in Rust. (Though Embark Studios is doing some crazy stuff with ML physics.)

rapier