Job van der Zwan

Voronoi Stippling Notebooks

Have you, by any chance, experimented with per-channel stippling?

Fabian Iwand

Well, there's this HSL version (which uses the much-faster LBG stippling method)
https://observablehq.com/d/39f417c92bd64935

Here's the black and white version of that:
https://observablehq.com/d/58dcf8ef3d5aa78d

But per-channel I've so far only done manually (copy a channel from GIMP, stipple, copy back to a channel in a different layer in GIMP).

Neat!
- I was actually looking for something like https://observablehq.com/@fil/linde-buzo-gray-rgb-color-stippling (which I only found afterwards, ironically via Google).
- I also found https://www.youtube.com/watch?v=93dm7nw29KY (uses LBG + Voronoi, stable on videos - impressive!).
- Looked for optimal transport (remembering Fil's experiments) and came across https://arxiv.org/pdf/1810.00118.pdf

Unfortunately that rabbit hole directed my attention back to an older, mostly unrelated project of mine. ¯\_(ツ)_/¯

(By the way, is the notebook slug supposed to be "untitled"?)

Oh I got one of those too! Didn't show up in my search for some reason:

https://observablehq.com/@jobleonard/color-stippling?collection=@jobleonard/voronoi-stippling-notebooks

That video is very cool. The whole idea of LBG stippling is that it minimizes the stipples that update, so it makes sense that it's stable. What he might be doing "behind the scenes" is iterate a few times with relaxation before showing the result to move the stipples too.

Is the idea to do a sort of adaptive multilevel optimal transport across Voronoi cells instead of a fixed grid?

(no, the notebook is from before you could rename your notebook URLs, and I decided not to update it to not break old links)

You can find more details about the video in its description (e.g. the software used).

The process for animations is (also) described in the paper's video introduction, embedded in: http://graphics.uni-konstanz.de/publikationen/Deussen2017LindeBuzoGray/index.html

I didn't find the general idea in the multilevel transport paper (as far as I understood it from skimming over) groundbreaking, but the illustrations (and some other recent work) gave me a push to take another stab at https://observablehq.com/d/4cb8dde7afcae890

Hi, I really love what you have done here and it is a lot of fun. Have you been able to get it to export to SVG or could you give me a quick pointer on how to do it?

Marcus Johnson

Sure! I got a color and a black and white version too: https://observablehq.com/collection/@jobleonard/voronoi-stippling-notebooks

Thanks, is that a public notebook as the link doesn't seem to work for me?

Huh, you're right, the list was private. Published now! Also, the two notebooks most interesting to you would be these:
https://observablehq.com/@jobleonard/a-fast-colored-stipple-generator
https://observablehq.com/d/58dcf8ef3d5aa78d