box2d

For typical game physics engines... not that much. Math libraries like Eigen or Blaze use lots of template metaprogramming techniques under the hood that can help when you're doing large batched matrix multiplications (since it can remove temporary allocations at compile-time and can also fuse operations efficiently, as well as applying various SIMD optimizations), but it doesn't really help when you need lots of small operations (with mat3 / mat4 / vec3 / quat / etc.). Typically game physics engines tend to use iterative algorithms for their solvers (Gauss-Seidel, PBD, etc...) instead of batched "matrix"-oriented ones, so you'll get less benefits out of Eigen / Blaze compared to what you typically see in deep learning / scientific computing workloads. The codebases I've seen in many game physics engines seem to all roll their own minimal

TIL Box2D must not be serious code because it doesn't use copious amounts of explicit temporaries[0]. And just for the record, I'm very glad Erin Catto decided to use operator overloading in his code. It made it much easier for me to read and understand what the code was doing as opposed to it being overly verbose and noisy. [0]: https://github.com/erincatto/box2d/blob/main/src/collision/b...

Well, it’s a pretty huge topic. I recommend taking a look at the SIGGRAPH course notes on contact and friction simulation: https://siggraphcontact.github.io/ Also, look at some recent papers on SIGGRAPH and SCA, such as: - https://matthias-research.github.io/pages/publications/PBDBo... - https://mmacklin.com/primaldual.pdf - https://arxiv.org/pdf/2201.10022.pdf Note that these are all cutting-edge stuff, and most physics simulations in production still use more traditional methods (which you can learn from Box2D’s source code and related GDC slides). The links: - https://github.com/erincatto/box2d - https://box2d.org/publications/

Box2D https://github.com/erincatto/box2d I went over every file of this writing a Unity plugin for it in work once. I was really impressed, learned a lot.

Author here. This demo showcases liquidfun-wasm[0], my effort to revive liquidfun[1] (a fork which adds fluid simulation and soft-body physics to Box2D[2]). to make liquidfun-wasm, I repurposed my existing box2d-wasm[3] and pointed it at a different release of Box2D — a commit obtained by rebasing liquidfun over 7 years of upstream Box2D changes[4]. the end result is that liquidfun is now distributed in WebAssembly and with TypeScript typings for the first time. The TypeScript typings are generated from WebIDL bindings via my webidl-to-ts[5] compiler. this demo in particular aims to bring to the Web the shaders from the liquidfun EyeCandy demo[6], and show how fast JS can run if you avoid incurring the garbage collector (the main loop tries not to allocate objects). the demo repurposes gravity and drag calculations that I'd used previousl

By comparison Box2D is actively maintained: https://github.com/erincatto/Box2D/commits/master This is the problem when you fork a project. :/

It is. I tried it out but it doesn't have the fidelity w.r.t I/O and 'hooks' I was looking for. Then again, I'm working beyond reinforcement learning. More advanced A.I necessitates more advanced gym. I highlighted box2d as its an opensource physics/sim engine. The sim/physics engine is 90% of the 'gym'. I'm sure if there was money involved, the sims/hooks/etc that are being sourced and packaged around could get a lot more advanced more quickly. i.e : https://github.com/erincatto/Box2D/issues

I've found the book Game Engine Architecture extremely helpful with this. http://www.amazon.com/Game-Engine-Architecture-Jason-Gregory... If you're looking to find out how a physics engine works you should check out Box2D, it's an open source 2D physics engine. https://github.com/erincatto/Box2D