turtletoy.net

What is Turtletoy?

Turtletoy is a browser-based creative coding playground for pen plotters. You write small JavaScript programs against a Turtle graphics API — forward, turn, penup, pendown — and the site renders the result as line art. The output is meant to leave the screen: designs export as SVG or GCODE for pen plotters, laser cutters and CNC machines. The tagline "Joy is in the craft" signals the intended audience: people who enjoy the code itself, not just the finished drawing.

What you actually do there

• Code a turtle. A few lines of JavaScript produce single-line drawings, generative patterns and geometric studies. No build tools, no local environment.
• Download ready-to-plot files. The site offers SVG and GCODE exports described as crisp and scalable, aimed at machines that draw or cut physical lines.
• Browse and remix. Every turtle is open source and shareable by link, so you can read someone else's code, fork the idea and change it.
• Compare against a gallery. A "most loved" list and "latest contributions" feed show what the community is making, from attractors and noise fields to Truchet tiles and maze generators.

Who it suits

The trade-off is deliberate: a minimal command set keeps the barrier low but limits what any single sketch can express. Much of the appeal is watching simple rules — noise, recursion, tiling — turn into something worth putting pen to paper for.

A practical next step

If you own a plotter, open the most-loved gallery, pick a design with visible line structure such as a Truchet-tile or contour piece, download the SVG and run a test plot on cheap paper before committing to good stock. If you are there to learn, open any turtle and change one number — a step size, a loop count, a noise seed — then re-run. That single edit is the fastest way to understand how the drawing is constructed, and it is exactly the remix loop the site is built around. For a broader community of plotter-focused generative work, Observable hosts notebooks in a similar spirit, though without the plotter-export focus.

How do I export Turtletoy designs for a pen plotter?

Turtletoy is built around plotter-ready output: its own description says you can “download crisp, scalable SVG and GCODE files optimized for pen plotters, laser cutters, and CNC machines.” So the workflow is less about conversion and more about choosing the right file format for your machine and checking the result before you commit ink to paper.

Which format to pick

A practical export routine

1. Open the turtle you want and run it so the canvas shows the finished drawing.
2. Use the download or export control on the page and choose SVG or GCODE.
3. Open the SVG in your plotter software and check the drawing fits your paper size — generative pieces often run to the canvas edge.
4. Confirm the paths are strokes, not filled shapes, unless you actually want fills.
5. Do a dry run with the pen lifted, or plot on scrap paper, before using good stock.

What to watch for

Turtles are open source and remixable, so a design you like may have a sibling version with different density or scale. If a plot looks too crowded, look for a remix rather than editing coordinates by hand.

For pen plotters specifically, the biggest variable is pen-down time, not file format. A dense generative pattern like a noise field or contour map can take far longer to plot than its on-screen simplicity suggests. Estimate by path length, not by how the thumbnail looks.

If you want to compare approaches or find ready-made designs, the gallery on Turtletoy is the natural starting point; for plotter-specific setup and troubleshooting, the community around AxiDraw and Inkscape covers the software side well.

A useful next step: pick one simple turtle, export it as SVG, and plot it at two different scales. That single test tells you more about your pen, paper, and speed settings than any amount of reading.

What JavaScript commands does Turtletoy's turtle graphics API support?

Turtletoy's API is a deliberately small set of turtle-graphics commands in JavaScript, not a full drawing framework. From the site's own description of the API, the core primitives are:

• forward() — move the turtle forward, drawing a line as it goes.
• turn() — rotate the turtle, typically in degrees, changing the direction of subsequent moves.
• penup() — lift the pen so movement no longer draws.
• pendown() — lower the pen to resume drawing.

That's the essential loop: move, turn, and control when ink is applied. Everything visible in the gallery — single-line art, generative patterns, and plotter-ready output — is built by repeating these commands with loops, variables, and math, rather than by calling dedicated shape or curve functions. The site frames this as "joy in the craft," which is a fair signal that the API rewards people who want to construct geometry themselves.

What this means in practice

A simple spiral, for example, is just a loop that calls forward() with a growing distance and turn() by a fixed angle each pass. More elaborate pieces on the site, such as attractor plots or contour-line islands, layer in JavaScript math on top of the same four commands. The API's surface is small, so the interesting work happens in your code, not in library features.

Exports and where the commands lead

The output side matters as much as the drawing side: Turtletoy describes exports as crisp, scalable SVG and GCODE files optimized for pen plotters, laser cutters, and CNC machines. So the same forward()/turn() sequence can become either a screen image or a physical drawing. Every turtle is open source and shareable by link, which makes the gallery a practical reference — reading someone else's short script is often the fastest way to learn a technique.

Who it suits

If you want to see the exact function signatures and any additional helpers, open a turtle in the editor and read its source — the API reference and the code sit side by side. You can browse examples at Turtletoy.

Can I remix or reuse other users' Turtletoy creations?

Yes. Turtletoy is built around sharing and remixing: every turtle on the site is open source, so you can open another user's creation, read the code, edit it and publish your own version. The gallery entries shown on the homepage — for example "Cubic cityscape #1" by reinder or "Invaders" by ge1doot — are the same kind of open turtles you can fork rather than finished, locked artwork.

What remixing looks like in practice

• Start from someone else's turtle. Open a piece you like, study the JavaScript turtle commands it uses (forward, turn, penup, pendown), then change parameters, colours or geometry.
• Learn by reading. Because the code is visible, a beginner can take a working pattern and tweak one number at a time to see what changes.
• Publish as your own. The site describes sharing with a single link, which is how remixes circulate and get credited back to the original.
• Download for hardware. Exports are offered as SVG and GCODE aimed at pen plotters, laser cutters and CNC machines, so a remix can leave the screen and become a physical drawing or cut.

The trade-offs to weigh

A concrete first step

Pick one "most loved" turtle with a lot of favourites, such as "Cubic cityscape #1", open it, and change a single value — a rotation angle or a loop count. Re-run it, then save your variation with a note crediting the original author. That habit keeps the remix culture on Turtletoy healthy and makes your own contributions easier for others to build on.

What kinds of generative art can I make with Turtletoy?

Turtletoy is built around single-line, pen-plotter-friendly generative art: patterns drawn by a virtual turtle that moves with simple commands like forward, turn, penup and pendown. Because every turtle is open source and exportable as SVG or GCODE, the range is less "anything JavaScript can render" and more "anything a pen, laser or CNC tool can trace."

What people actually make there

Looking at the site's own galleries, the recurring genres are:

• Mathematical attractors and curves — e.g. The Rössler Attractor, Torus, Moebius gears. These suit anyone who wants to see a differential equation turned into a physical drawing.
• Noise and flow fields — Simplex Noise Waves, Curl Noise, Random weed. Good for organic, wind-blown textures that stay within a single continuous line.
• Contour and terrain studies — Contour Lines Island, 3D Contour Lines Island, fractal terrain. These mimic topographic maps and work well as plotter pieces because the lines never need filling.
• Tiling and Truchet patterns — Hexagon Truchet, Bezier Truchet tiles, Unbalanced anisohedral tile. Useful if you want repeating structures with controlled variation.
• Geometric and architectural abstractions — Cubic cityscape #1, Interpolated random grid, Polygon hatching. These read as clean line art rather than painterly images.
• Playful figurative sketches — 729 Faces, Invaders, Threes on lake. A reminder that the API is simple enough for cartoonish, low-detail drawings too.

How to choose your starting point

If you already have a plotter or laser cutter, browse the "Most loved" section first — those turtles have survived other people's attempts to plot them. If you want to learn the API, remix a short turtle such as a Truchet tile or a random weed rather than starting from an attractor, because the code stays readable.

For a concrete next step: open one turtle whose output you like, change a single number in its parameters, and export the result as SVG. That one edit will tell you more about whether Turtletoy fits your workflow than reading about it.

Do I need prior coding experience to start creating on Turtletoy?

No formal coding background is required, but you do need a willingness to read and tweak short snippets of JavaScript. Turtletoy is built around a deliberately small turtle graphics API — the page names the core commands as forward, turn, penup and pendown — so the vocabulary you must learn is tiny compared with general-purpose programming. If you can follow a sequence of instructions like "go forward 100, turn 90 degrees, repeat," you can produce a valid drawing.

What actually determines your starting difficulty

• Your goal. If you want to download and plot existing designs, coding experience is irrelevant: the site offers ready-to-plot designs and plotter-ready SVG and GCODE exports for pen plotters, laser cutters and CNC machines.
• Your goal, second version. If you want to remix, every turtle on Turtletoy is open source, so you can open someone else's sketch, change a few numbers and see what happens. That is the lowest-effort entry point and it teaches the API faster than reading documentation.
• Your tolerance for debugging. Generative art fails quietly — a wrong angle produces a tangle rather than an error message. Beginners often find this harder than syntax itself.

A realistic first session

Pick one of the simpler, highly-loved examples, such as a Truchet-tile or maze pattern, and change a single parameter: the tile size, the number of steps, or a rotation angle. Reload, compare, repeat. Once a change produces something you like, you have effectively written your first generative sketch, and the commands you used are the same ones behind the more elaborate pieces on the site.

Where prior experience helps most

Decision criterion

Start with remixing if you are unsure. If, after changing numbers in two or three existing turtles, you find yourself wanting to control why the output changes, that curiosity is the signal to learn the API properly — and to look at the featured and most-loved collections for patterns worth dissecting. If instead you only ever want finished artwork to plot, skip the coding entirely and use the download path.