This is a Rust implementation of the Raytracer described in Peter Shirley's Ray Tracing in One Weekend. It is indended for my own learning purposes. The initial implementation is faithfully following the book implementation. My intention is to use this as a test bed for playing with threading, SIMD and general optimizations in Rust and also to complete follow up books to Ray Tracing in a Weekend.
I found the book via Aras Pranckevičius' blog series on his toy path tracer experiments which was my inspiration for doing this, thanks Aras!
Requires Rust 1.27 for SIMD support.
The easiest way to build and run the path tracer use the command:
cargo run --release
Using nightly will give slightly better performance due to use of std::intrinsics::cttz. To build with core intrinsics enabled make sure you have a nightly build of rustc installed and use the command:
cargo +nightly run --release --features core_intrinsics
If you build without the --release flag the application will be very slow!
The sphere collision path can run through several SIMD backends. On x86 the best one is
detected at runtime; the PATHTRACE_SIMD environment variable overrides the choice:
| Value | Backend |
|---|---|
scalar / fallback |
Plain scalar code |
sse4_1 |
SSE4.1 intrinsics |
avx2 |
AVX2 intrinsics |
portable / portable_simd / fearless |
fearless_simd portable SIMD |
auto / auto_vectorize |
fearless_simd #[simd] auto-vectorization |
The last two are provided by the fearless_simd cargo feature, which is enabled by default and makes
the portable backend the default choice:
cargo run --release
PATHTRACE_SIMD=auto cargo run --release
Disable the feature (and fall back to runtime SSE4.1/AVX2 detection) with
--no-default-features.
See LICENSE-APACHE and LICENSE-MIT for details.