Here's their release of how they made it as well. Super interesting read. It's shaders all the way down. http://www.iquilezles.org/www/material/function2009/function...
Ha, that's my exact comment from the related reddit thread. Kinda cool, I wonder how often that happens? https://www.reddit.com/r/programming/comments/4msf41/elevate...
Watchful users can help out with this a lot. If you or anyone notice comments being cross-posted in the future, please alert us at hn@ycombinator.com.