Reimplementation of Matthias Müller's "Ten Minute Physics" demos in Rust with WASM + WebGL

ten-minute-physics-rs reimplements Matthias Müller's "Ten Minute Physics" demos in Rust with WASM + WebGL. Compared with the source pure Javascript implementations, many Rust versions run ~3x faster in Chrome on an M1 Max MacBook.

For all demos, please see https://cerrno.github.io/ten-minute-physics-rs/. Most can be interacted with by dragging the camera and/or objects on screen. This project is deployed to Github Pages after building with Github Actions.

Files in the src/ directory are labeled according to the corresponding source demo number. The top level index.{html,ts} files contain boilerplate code for all demos (such as initializing the <canvas> element, stats.js, and lil-gui). Each {demo}.ts file implements the generic interface defined in {lib}.ts, defining scene initialization parameters (THREE.js or canvas), scene setup (generally creating rendering elements, binding GUI elements, etc.), and update/render functions called by the index.ts main loop. Each {demo}.rs file implements a physics simulation in Rust, which is compiled to WASM using wasm-pack and instantiated/called by the corresponding {demo}.ts file to step the simulation.

Memory is shared between the WASM instance and JS via WebAssembly.Memory and Rust helper methods which return pointers to contiguous memory locations. For example, particle positions are stored in Rust as a Vec<Vec3> struct field. A wasm-bindgen getter is defined to return a *const Vec3. glam::Vec3 is repr(C), so each is a linear array of f32s somewhere in the WebAssembly.Memory buffer. For rendering in JS, a THREE.BufferAttribute is defined to reference a Float32Array referencing the WASM memory ArrayBuffer with the pointer (byte offset) returned from the getter and a known length (in this case, num_particles * 3).

Running

# install dependencies
npm install

# compile to WASM, run webpack, and spawn a local server
npm run serve

Then visit http://localhost:8080

License

This project is distributed under the MIT license.