Turtle graphics are a form of vector graphics. In its most basic form, there is an object that moves around the canvas, leaving a trail as it goes. It’s called turtle graphics because you can think of the object as turtle with a pen strapped to her shell. The turtle can do two things: 1) move in a straight line for a certain distance, and 2) rotate to face a new direction.
Today, we’ll try to come up with something interesting based on the noise concepts we discussed in the last two posts. We’ll put some dots (which we’ll call particles) randomly on a canvas and have them move according to rules based on our noise functions. This will create streams of particles; we’ll be able to see their paths on the canvas. In a fit of not-very-creative naming, we’ll call our project Streams.
Last week we talked about noise, specifically Perlin noise, which lets you vary a value randomly but incrementally, leading to a slowly changing value. We used it to draw the outline of a mountain range, but it can be used anywhere you need a value that changes a tiny amount at a time. Conveniently, this also works in two dimensions. In 2-dimensional noise, the x and y axes each have their own noise, and (and this is important) they are not the same.
Sometimes you just want to make some noise! In drawing terms, that means you don’t want a boring straight line; you want a straightish squiggly line which looks hand-drawn. Or you don’t want a flat surface, you want it to have some texture. You can generate these kinds of effects by adding some random noise, but how? There are a couple of ways to do this. We’ll cover some simple examples here.
Way back when I did my very first The Artist's Husband post , I used Javascript and p5.js to create a drunken lines drawing, a drawing where the direction of a line (as well as its color) is chosen by random. Doing this over and over again eventually fills the windows with a colorful image such as the one at the top of this post. Here is a Nannou app which does pretty much the same thing:
In my last post , we set up a basic sketch in Nannou. This week, we’ll look at a Nannou app. A Nannou app is like a Nannou sketch, but with more capabilities and tighter control of what is happening. They are very similar; in fact a sketch is just a shortcut for an app when you don’t need the features an app provides. This can save you some typing.
Now that you have Rust and Nannou installed , lets look at a basic Nannou sketch. A sketch in Nannou is a fast way to get a drawing displayed. Here is a simple one which just draws a rectangle and an ellipse on a colored background. use nannou::prelude::*; fn main() { nannou::sketch(view).run(); } fn view(app: &App, frame: Frame) { let draw = app.draw(); draw.background() .color(LIGHTBLUE); draw.rect() .color(ORANGE) .w(100.0) .h(200.0) .
In my last post , I mentioned Nannou , a generative art framework for the Rust programming language. While I am focusing mainly on drawing here, Nannou goes much further dealing with user interface, audio and video, and even lasers ! Its goal is to provide tools for artists building any kind of art installation. For drawing, it is similar to Processing in how it is used, and therefore similar to all the other frameworks I’ve discussed here, which are all based on, or at least inspired by, Processing.
This is my first real new post since 2020. All the ones posted at the end of 2023 were written back in 2020, and have been backlogged while we dealt with personal issues. New year, new posts! In my previous posts, I’ve explored some basic generative art in a variety computer languages and art frameworks. We tried Javascript with p5.js , Clojure with Quil , and Java and Processing .