I can also recommend this book when looking for something fun to implement while learning a new language. There is also the follow ups to this taking things a bit further:

https://raytracing.github.io/books/RayTracingTheNextWeek.htm... https://raytracing.github.io/books/RayTracingTheRestOfYourLi...

I did this ray tracing library in Rust inspired by these books: https://github.com/DanielPettersson/solstrale-rust

And also a small UI using the lib: https://github.com/DanielPettersson/solstrale-desktop-rust

Kind of not maintained anymore.. But fun way learning Rust..