Iām in London today, well, not really as Iām writing this last week, but when this goes out Iāll have been here the past couple of days. Iām attending a workshop about preservation, more specifically cultural preservation. Even more specifically preservation of photos uploaded to Flickr.
Cultural institutions, museums, (and of course people) have entrusted Flickr with large collections of photos. So what options are there for permanence and provenance of these collections if and when Flickr and/or the institution shut down.
How, why, and should they even be preserved?
Important stuff, and no time for writing newsletters and so the scheduled option is my friend.
# Pen Plotting Optimisation
More of the Truchet tiling this week, and this is all about escaping rigidity and then enforcing control. Letās grab a design in a continuation from last weekā¦
This is where we have to recognise our roll as an engineer vs artist. For some people those are the same thing, I wish I was one of those people. For me itās more of a general overlap.
Iāll start as an artist with an idea, and then promptly switch into engineer mode trying to āsolve the problemā. In this case itās āhow do I fill the page with tiles?ā, and having filled the page the problem is solved! Only, now thereās two new problems.
The first; is that now we have tiles that look like they join together, but donāt actually, and those tiles get draw in the order the were created in. In this case, large ones first, starting from the top down, then medium, then small and finally all the stuff around the border.
This causes trouble when we plot, as thereās often a small pause when the pen starts or finished a line, which means you get obvious āseamsā where one line ends and the next starts. Particularly obvious when doing concentric circles. We want our design to be seamless!
Most sensible people would use this bit of vpype: https://github.com/abey79/vpype?tab=readme-ov-file#plotting-optimization the Line merging (āwith optional path reversal and configurable merging thresholdā) linemerge command. Which will join the end of one line to the start/end of another line if theyāre close enough (threshold), looping over the whole lot until thereās no more lines to join.
Often done along with optimising using Line sorting (āwith optional path reversalā) linesort. Which means the plotter will draw all the lines in a way the reduces pen-up travel distance; if youāre drawing lots of parallel horizontal lines, thereās no point drawing them all left-to-right, as the machine will spend half the time moving the pen to the start of each new line, much better to draw them going back and forth.
Because Iām the worst at prioritising what I should focus my efforts on, I created my own joiner & optimiser. Below on the left is the original (which I promise you is) made up of separate tiles. On the right we can see (by giving them āfalse colourā) which lines have been joined up.
The second problem (as I see it anyway), is that while itās very satisfying to lay down the code needed to fill the page with a design, and for that code to actually work, the satisfaction of seeing the screen filled up with lines doesnāt always translate to the page.
Iād often find myself sometimes disappointed once the plotter had finished and the page filled, it was too regimented, too engineery.
The curious thing was that the process of taking the original design, where the lines were draw in code order, and running it through an optimiser and creating a new computer-logical order for drawing, would create plot designs that I hadnāt planned myself, and looked super satisfying to my artistic side when they were half plotted.
I often found myself stopping a plot before itād finished, so it looked something like this.
By surrendering to the optimising code, whoās logic I understood but could in no way predict, Iād end up with designs that were a proper combination of my original intent, the mysteries of the optimiser and the drawing of the machine.
Beautiful!
But also, we canāt have that now can we!
What if we could preview what itād look like if we stopped the plot halfway through?
What if we could throw away the last 20%, 40%, 60% of the lines? What if we could throw away the first 20%, 40%, 60%, whatever % of lines??
What if we could throw away the first and last 40% of lines, keeping just the middle 20%, and then invert that, throwing away the middle 20% and keeping the rest?
Well then we can start to do fun things like thisā¦
Although, Iām once again falling into the engineer trap of letting it fill the whole page, when really I should be experimenting with overlapping different truncated designs, rotating the page 180 between plot, using different types and thicknesses of pens and so on.
I guess if I started doing that, then Iād also eventually write the tools thatād allow me to preview those outputs.
All of which is to say, I think this reinforces the feeling we often get; that we, as artists & engineers, are working in collaboration with the code, the tools, the machines and the materials.
Itās the back and forth between what I was expecting, what I saw and then what I rolled back into code that gives me joy in exploring the endless paths we can take with our pen plotters.
Iāll be publishing the tools used above to create the ā70s Popā design, and the optimiser/truncator after the next newsletter, ācause I have āOne more thingā to write about. Although it should be noted that the optimiser/truncator was written to specifically work with the SVG created from my own generator. Itās not a universal tool.
For that you need vpype, which Iām pretty sure can do everything shown above (and more, faster), Iām just kinda a control freak who likes to build, understand and (yuck) maintain his own tools.
# THE END
Thatāll do it for this time. By the time the next newsletter comes out (28th November btw) I should have my studio floor all painted and everything back where itās supposed to be, which will be a huge relief. Iām looking forwards to having a few clear weeks before the end of the year where I can just do studio-artist things rather than panic/floor-painting/admin things!
Iāve still got a bunch of stuff to throw out (boxes of cables I havenāt used in years, various bits and bobs that I thought would be useful at the time and have never used, and so on), and some plan chests to keep paper, plots & prints flat and safe, and an Epson SureColor SC-P900 (the reliable choice for generative artists it seems) to order.
Then Iāll all be set up to get back into print & plotting fresh in the new year š¤ itās likely Iāll need the distraction.
Iām also, finally writing the script for the āMy Generative Handwritingā video, with a eye to getting it out early next month. Mainly so I can point people at it when I get asked āHow do you do handwriting on a drawing machineā.
Love you all
Dan
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