AxiDraw V3
The pen-plotter hardware (by Evil Mad Scientist Laboratories) that DesLauriers uses to output his generative code as physical drawings.
Run it
What it looks like when it goes wrong (3)
- Each stroke is drawn at a fixed line width; once the spacing between strokes is narrower than that width, neighbouring strokes overlap completely and the panel floods to flat solid black. Every stroke past that point is wasted — the tonal range has already collapsed to its darkest possible value, and the plotter just spends longer drawing lines nobody can see.
- The illusion of a flat grey depends on the gaps between strokes being small enough that the eye averages them into a tone. Past a certain spacing that averaging stops happening: the shape reads as a handful of separate parallel lines laid over a boundary, not as a toned fill.
- The boundary is elongated along one axis. Hatching close to that axis produces long strokes that run with the shape; hatching close to perpendicular to it chops the same fill into short, choppy segments that cut across the form instead of following it — a real illustration mistake, not just a different look.
Clean-room implementation — written from the described algorithm, not from source. Reuse policy
What it is
The AxiDraw V3 is pen-plotter hardware from Evil Mad Scientist Laboratories — “the AxiDraw V3 by Evil Mad Scientist Laboratories,” as Matt DesLauriers names it. He describes what a pen plotter is at the general level: “a piece of hardware that acts like a robotic arm on which you can attach a regular pen.” Michael Fogleman calls the AxiDraw “a very nice modern pen plotter.” Between the two: a real pen, gripped and moved by an arm, doing whatever the software driving it says.
What it is good for
Anything expressible as strokes rather than pixels. Take DesLauriers’ definition at face value — the hardware attaches “a regular pen” to an arm — and a pen has exactly the vocabulary a pen has ever had: draw a continuous line, lift it, put it down somewhere else. There is no fill call. A shape that needs to read as solid has to be built out of enough strokes to look that way — hatching, a tight spiral, repeated passes — the same trade every pen-and-ink medium has always made, now decided by code instead of a hand.
A minimal real example
The constraint is easiest to feel side by side: render one shape twice, once with a fill call and once as the set of strokes this hardware could actually draw, and watch what has to change to get from one to the other.
Idioms
Two relationships to this hardware show up in what’s here, and neither is
“the” way to run one. DesLauriers treats it as a plain output device — a
generative sketch produces a drawing, the drawing gets sent to the plotter,
done. Fogleman went a level lower and wrote axi, his own
unofficial control library for the AxiDraw V3, giving it its own motion
planner, path-order optimizer, and turtle API rather than routing through
whatever the vendor ships.
axi’s turtle interface has its own page here as turtle graphics, and the dragon curve is the example it ships to demonstrate it.
What it makes easy
Getting generative or vector code onto paper without touching it by hand —
the whole reason DesLauriers has one. Once something like axi is doing the
driving, sequencing hundreds of paths and moving the pen between them stops
being something you have to solve yourself.
Getting started
Nothing gathered here covers setup — no driver install, no port
configuration, no comparison against the vendor’s own control software. Both
accounts behind this page are about what the device is and how two people
chose to work with it, not how to plug one in. For that, go to Evil Mad
Scientist Laboratories’ own documentation, or to axi’s README directly if
driving it over serial yourself is the route you want.
Connected to
Contrast with: axi