Rustracer

A real time path tracer in Rust and WGPU.

This is based on the "Ray Tracing In One Weekend" book and (partially) its sequel.

My goal is to make a real-time path tracer that can run on low end hardware (integrated graphics).

Screenshots

Day scene, 160 fps.

Night scene, 2 fps (darkness requires more samples reducing fps).

Controls

WASD to move around. Space to go up, Left Shift to go down.

Move your mouse to look around. By default it will be locked. Click to unlock it, and click again to lock it.

How does it work?

• It runs the path tracer in a compute shader and stores the result in a texture.
• Then it copies the texture to the screen via the fragment shader (with a fullscreen rectangle mesh).

All shaders are in src/shaders. The compute shader consists of shaders/compute_shader.wgsl and shaders/raytracer/*.

Constants

If the raytracer is too slow, you can reduce the settings in rustracer/src/main.rs here:

let renderer = rst_render::Renderer::new(
    window.clone(),
    &materials,
    ShaderConfig {
        samples: 8,
        bounces: 4,
        antialiasing: false,
        motion_blur: true,
        downscale: 4.0,
        // ...

You can edit it to match your hardware.

• samples is the number of samples per pixel. (2-4 low, 6 medium, 10+ high)
• bounces is the number of bounces per ray. (2-4 low, 6 medium, 10+ high)
• antialiasing is whether to use antialiasing. (true or false)
• motion_blur is whether to use motion blur. (true or false)
• downscale is the amount to downscale the image by. (1.0 is full resolution, 2.0 is half resolution, 4.0 is quarter resolution, etc.)

Build

• Install Rust
• Clone the repo git clone https://github.com/Mrmayman/rustracer.git
• Navigate inside the new rustracer folder cd rustracer
• Do cargo run --release

Notes:

• You can use this as a library by importing rst_render in your project.
• If you find any problem with the code, feel free to contact me or start an issue in the repository.
• The code may not be the best, I'm still rather inexperienced in programming.
• You can check out the old (pretty horrible) versions of this in the old_versions folder. There's a README.md there too, for more information. Update: This is no longer the case. Go to commit id baa1bce68a68b001a8189469274fab3158291cb7 for this.

To-Do

• Texture support
• Noise texture support
• Hybrid rendering (ray tracing + rasterization)
• Skyboxes
• Sky models (procedural)
• Volumetric rendering (fog, smoke, etc.)
• Point lights

Credits

Ray Tracing in One Weekend

Ray Tracing: The Next Week

glslSmartDenoise (for denoising the image)

AMD FSR 1.0 (for upscaling, disabled by default)