I did Ray tracing in one weekend in Rust with minimal dependencies. I've made some changes to the original behavior where I felt like it, but the output still results in a ray traced image. The resulting image will always be exported to a file called "img.ppm", exporting only happens at the end of rendering, all in one* go.
A small but cool feature is that I made a progress bar that updates in place. It does this by writing directly to the terminal and using ASCII escape codes. It consists of a type of message (currently I only use INFO) a message which represents what the progress bar is about (rendering image, sending jobs, etc.). The progress bar also shows an ETA until it's done. It's calculated based on how long the progress bar has been progressing and how far along it is. This does mean that if it takes gradually more time (for example with a bottom heavy render) the ETA won't really be accurate. Maybe in the future I'll do some more predictions on the ETA, but for now it works fine.
Additionally, rendering can be done in a multithreaded fashion. The Camera struct has a rendering function threaded_render. The threaded_render function will create a thread pool and queue jobs (through a channel) for every single pixel. Inside these jobs is a channel transmitter that will send back the rendered pixel as well as the location it's supposed to go in the image. When the thread pool no longer has any jobs, aka every pixel has been rendered, the entire image is transformed into a massive string and written all at once. The thread pool implementation isn't perfect, it doesn't handle the case when the job panics and will just crash. I did implement a shared state, which could be easily extended. I assume that's the best way to keep track of paniced threads and reinstate them, but I didn't look it up and I doubt I'll work on it unless if it ever becomes a problem.
A winit application is integrated in the codebase. An application can be created by simply passing a width and height into the constructor. It returns an event loop and an application. An event loop has to be passed to the camera. Then when rendering, a preview window will show the render as it's happening! This is honestly quite simple but the addition look amazing!
I plan to still add/ improve the following:
- GPU rendering
- Eventually I plan to render my pixels with WebGPU which should be massively faster. But I've never worked with the GPU so we'll see.
- PNG
- I'm planning to look into PNGs to see if I can directly render to that instead of ppm. ppm is easy, but god damn it also takes up some space.
- Ray tracing beyond
- This was pretty damn fun to do, so maybe somewhere down the line I'll do Ray tracing in a week and or Ray tracing the rest of your life. But I think I'm more interested in the GPU, so we'll see where things go.
- Alternatively, I saw that someone was working on GPU Tracingmaybe I'll do that, who knows