This was the first time I’ve ever seen these. Thanks for the walkthrough. When I was in grad school I remember these books and all the freshman who could see th

This was the first time I’ve ever seen these. Thanks for the walkthrough. When I was in grad school I remember these books and all the freshman who could see them telling me I had wrecked my eyes from spending countless hours in the computer lab. They weren’t wrong but I pretty much gave up until seeing progressive refinements in this tutorial. Very cool!