You can post this without the Show HN prefix but Show HN is for things you've made people can try and excludes most reading material like blog posts, etc. Take a look at https://news.ycombinator.com/showhn.html
Apologies, I removed the prefix. Didn't realize this didn't qualify. It's a full implementation of radiance cascades that anyone can immediately try out. But does include an explanation and walkthrough.