📙 #078 - Making Brushstrokes
And The VORTEX
When I was a kid there was a TV program called “The Adventure Game”, each episode (from series 2 onwards) ended with The Vortex.
The game was played on a triangle/hex lattice (3-4-3-4-3-4-3), with the celebrity player, often a children’s tv presenter, at one side and the “vortex” at the other, which was invisible to the player. They’d take it in turns to move, and if they player moved into the vortex’s space they were eliminated.
Obviously with the vortex being invisible this was somewhat a game of chance, but it did allow me to divide tv celebrities into those who were cool, and those who clearly didn’t fucking understand game theory, probability, and optimising a statistically correct strategy.
No Keith No! Don’t move to that spot on the very edge, now you’ve limited the number of viable next moves and reduced your chances of winning. Oh God, he’s moved backwards, the twat!
And that’s how Keith Chegwin got sucked off by the vortex! This would never have happened to Maggie Philbin*.
I was 9 at the time, and not yet diagnosed with autism, but the signs were there.
# MAKING COHERENT BRUSH STROKES
I’ve been plotting my postcards for the #ptpx2025 Pen Plotter Postcard Exchange, with (sometimes) fancy ink, brush pens and the ArtFrame drawing machine, which allows me to control the height of the brush using the magic of GCODE.
I wanted to share a little of the behind the scenes on this one ‘cause I think it’s fun. Here’s an image to get started, it’s my own mini version of the Vortex!
The “game” is to generate nice sweeping brushstrokes that start at the top of the page/design and swoosh their way generally down. So here are the rules…
Randomly start at either position 0, 1, or 2.
Each “turn” you have a 10% chance of moving up, 20% chance of moving sideways and 70% chance of moving down. If you can’t move up, roll again. If there’s more than one option to move sideways or move down, flip a coin to see which way you go.
When you reach the bottom, take one more turn then end the “game”.
If there’s less than 8 points in the final path, throw it away and start over.
This gives us a “random walk” that always starts at the top, and will eventually make it’s way to the bottom. Because they’re all based on the same underlying lattice/substrate they’ll be consistent.
Next stage, throw in a pendulum.
Ignore the complicated one on the right for the moment.
Imagine a single point at the top of the page, and attach a pendulum that swings back and forth (and attach a pen to that pendulum). The pen would swoosh back and forth drawing an arc over and over until it rips through the paper (bad).
Imagine a second point near the bottom of the page, and now let the pendulum’s pivot point slowly move from the top to the bottom, while swinging back and forth. You’d end up with back and forth swooshes going down the page (better, but boring).
Now, much harder to imagine, but thankfully pretty easy to code, a pendulum that swings back and forth, as the pivot point it’s attached to slowly moves along the path we created.
Here’s the complicated one from above, with all the points along the path. BUT, an added rule; as the brush/line moves downwards the line gets thicker (and on the drawing machine we move the brush closer to the paper), and as we move upwards the line gets thinner (we move the brush away from the paper).
You’ll probably have noticed there’s actually two lines 🤔
This is because I want the main black line, and then a “sympathetic” supporting coloured line. The two lines are created by starting two pendulums at slightly different angles & swinging at slightly different speeds.
They’ll slowly move out of sync as it moves towards the end of the design, but because they follow the same path they’ll be in roughly the same area (as opposed to both lines doing their own thing).
# INK
I need to get Kitty to write on some of these and then get them into the post. I have, of course, plotted far too many so I’m going to be sending extra ones out over the next few months, and Patreon.
# THE END
For lots of my friend 2026 has started as terribly as 2025 finished. So let’s just go with fuck you 2025 and fuck you 2026 too while we’re at it, may as well get it in now. I hope your holiday time and new year was okay, but sending my love if it wasn’t, fwiw.
I’m spinning things back up here & getting back into my stride, with the next Drawing Machines 101 video going out soon. Certainly sooner than the next newsletter which’ll be with you on Thursday, 22nd of January.
Love you all,
Dan
🧡
* Because Maggie Philbin was in series one, and the vortex wasn’t introduced until series two.