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.