rapier VS bevy

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.)

bevy_math also uses glam, re-exported in the prelude: https://github.com/bevyengine/bevy/blob/cc69fdd0c63ea79fda4f...

Since my project is built with Bevy, understanding its core concepts was very important. Bevy's entity-component-system (ECS) architecture makes game development modular and efficient, allowing for highly decoupled systems.

Not a very impressive example yet, it's mainly there for our CI system[1] to ensure that no one accidentally breaks the meshlet feature, but there is an example you can run to get a basic idea of the feature.

You can download Bevy https://github.com/bevyengine/bevy, and run `cargo run --release --examples meshlet --features meshlet`. After it compiles you'll get prompted to download a bunny.meshlet_mesh file. Click the link to download and create and place it in the appropriate folder, and then run the example again.

There's also this video from the Bevy 0.14 release notes demonstrating it, but performance/quality has improved a _lot_ since then: https://bevyengine.org/news/bevy-0-14/many_bunnies.mp4

[1]: https://thebevyflock.github.io/bevy-example-runner

Here, give it a shot - I'm at work so I can't try again right now, but last I did was use claude+context, chatGPT 4o with just chatting, Copilot in Neovim, and Aider w/ claude + uploading all the files as context.

I even went so far as to grab relevant examples from https://github.com/bevyengine/bevy/tree/latest/examples#exam... , adding relevant ones as I saw fit.

It took a long time to get anything that would compile, way longer than just reading + doing, and it was eventually wrong anyway. This is a recurring issue with Rust, and I'd love a workaround since I spend 60+h/week writing it. Probably a skill issue.

https://gist.github.com/jodavaho/8fb042fab33c1aaa95cd67144da...

I was looking through the source code for Bevy's Screen-Space-Ambient-Occlusion (SSAO) implementation and noticed they are using blue noise as well:

https://github.com/bevyengine/bevy/blob/56d559102858d4ce8a5b...

That link takes you to this shadertoy:

https://www.shadertoy.com/view/3tB3z3

Ah yeah pipeline compilation is a very non-trivial problem[1]. Unreal is also struggling with this a lot. I hear you that it's an issue.

The Bevy issue you want to follow is https://github.com/bevyengine/bevy/issues/10871.

[1]: https://therealmjp.github.io/posts/shader-permutations-part1 + https://therealmjp.github.io/posts/shader-permutations-part2

It's partly because WebGPU has very conservative default texture limits so that they can support old mobile devices, and partly it's a problem for engines that may have a bunch of different bindings and have increasingly hacky workarounds to compile different variants with only the enabled features so that you don't blow past texture limits.

For an idea of bevy's default view and PBR material bidnings, see:

* https://github.com/bevyengine/bevy/blob/main/crates/bevy_pbr...

* https://github.com/bevyengine/bevy/blob/main/crates/bevy_pbr...