I've been meaning to follow this book for a bit now, so here I am.
The book in question is the well known Ray Tracing in one weekend book by Peter Shirley, Trevor David Black and Steve Hollasch.
The code isn't an exact copy of theirs, I coded in my style with some of my ideas and understandings, but the ideas are basically the same.
The images in the ./img directory were created at different steps as I was progressing through the program. They are alphabetically ordered from oldest to most recent.
Here's the final render:
