This is fantastic writing. I didn’t know I needed triangulation so much in my life.
I’m now actually curious esp. how you did the “chalk” drawings :) And also the 3d surfaces, they look cool too :)
The chalk drawings are just static images (I drew them with Procreate on an iPad). I was going to render them all consistently, but in order to finish I cut some corners. I don’t think it would be too hard to make a chalk shader, but it would require building a vector editing tool or something because it took too long to place all the points in code. :)
And how about the 3d surfaces? Did you draw them from code pixel by pixel, or with some tools?
Ah, all the live visualizations are rendered with webgl. The terrain and parabaloid are basically the same shader, although the terrain has dynamic lighting and the parabaloid doesn’t. I could unify them…
The trick to the effect — that fake dithering look — is that every other pixel has less color depth than the pixels next to it. So half the pixels are full color, the others are like 16-bit (or something). Basically just chops off the bottom few bits of the RGB values of every other pixel. I played with some actual dithering patterns, but I liked the look of this a lot, and it’s really simple to code.
I just wanted to add that this is one of the best math/algorithm article I’ve read in a really long time.
And with really great visual support.
Long time lurker, first time commenter. Amazing post, I might just try implementing Delaunay Triangulation myself.
Interesting to note that the Stolfi of the work cited is the slightly controversial Jorge Stolfi, current bane of crypto scammers.