Again, thanks for the thorough and constructive answer, it doesn't come off as mean, on the contrary I appreciate it :)

I strongly agree that teaching is absolutely the best tool for learning. I wrote this article in part because I got inspired by the "What I cannot create, I do not understand" quote by Feynman.

I agree that the article is disorganized, and it's not only a feeling: it literally is! I had to shuffle around parts of the chapter about radiometry because I couldn't find the right place for it. I was kind of in a rush because I submitted this article as part of 3blue1brown's summer of math exposition.

I find it interesting that between the 3rd and 4th edition of pbr book, chapters have been reorganized too. Monte Carlo Integration has been moved to an earlier chapter before radiometry, reflection models..etc which I found confusing, but I suppose the authors had a good reason to do that. So I have a lot to learn on how to improve my writing and how to organize ideas into something coherent.

[0] https://some.3b1b.co/

Keep with it! And that reorganization between editions is a good reminder that things don't have to be perfect and can always be improved upon. We call these things "soft skills" but I think we've made a terrible mistake in implying that communicating is easy lol. Often it can be harder than the work itself! I think you got a good attitude and it'll take you far. So good luck on your submission! And FWIW, Monte Carlo Integration confused the hell out of me until I figured out how beautifully simplistic it is. If it hasn't clicked, keep with it. It eventually will.