A renderer I have been developing during the raytracing course in SPbU.

This repo is a self-contained (unidirectional) CPU-only raytracer written in Odin programming language.

The design and implementation are based on @lisyarus raytracing course.

This project uses just, a handy command runner.

To build in release mode, simply run

just release-build

You can check the [justfile] for more commands.

The resulting binary will be named by the repository directory name, raytracer-odin by default. Provide a glTF file to render and additional rendering parameters from CLI:

./raytracer-odin <path-to-gltf> <output-file-name> \
    --width <result image width> \
    --height <result image height> \
    --ray-depth <max raytracing recursion depth> \
    --num-samples <number-of-samples-per-pixel> \
    [--env-map <path-to-env-map>] \
    [--debug] [--continious]

If you add --debug flag, it will additionally open a window you can preview intermediate output in.

--continious flag makes raytracer ignore number of samples provided and and it will instead render continuously until it is interrupted with CTRL+C or the debug window is closed.

If compiled with EXPENSIVE_DEBUG=true feature, the debug window will get additional functionality. By hovering over the pixel, you can see some path which were started from that pixel. This can be disabled by pressing Z. You will also be able to preview the internal acceleration data structure. To configure which layer is visible, use X and C buttons.

There is also a concept of debugging layers. By default, the image is rendered on layer 0, which you can switch to by pressing 1 on the keyboard. However, when rc_set_* function is called in the implementation, the additional sample is recorded on a given layer. This layer can be then viewed by pressing the corresponding number key.

Finally, each layer not only collects information about the average of the samples, but also tracks additional data. By pressing Q-W-E-R-T-... you can switch between different preview features, and, for example, render the value of the last sample, the variance of the sample, or highlight NaNs and infinities, and so on.

Note that a very limited subset of glTF features are supported.

If you use blender, make sure to configure the export correctly. All images must be exported as JPEG or PNG. Make sure to apply all modifiers and limit the scope of your materials to the subset described in glTF spec under BRDF implementation section. Bake textures if needed.