Nature

"I think that I shall never see, a poem lovely as a tree"
-Alfred Joyce Kilmer

It's often said the beauty of nature far surpasses that of man. With the goal of this site being to generate pretty pictures algorithmically, I thought it would be interesting to think about how nature works from this perspective, so we can shamelessly rip off its ideas.

There are a small amount of types

Nature seems to work with "alphabets", ie a small number of types that combine together at different levels to produce different behaviour.

Eg quarks combine to form electrons/protons/neutrons which combine to form the chemical elements. I don't think this is just how science has been modelled by humans, but rather a necessary part of its ability to generate complex outcomes like the universe & nature and intelligent beings like us actually thinking and experiencing it all.

Falling Leaves

Click on the image on the left to load the canvas demo (requires FireFox or non-IE browser). As with all of these demos, try clicking reload a few times to see different random versions. Just an idea I had while riding my bike home, looking at fallen leaves (it's the start of winter here) I changed the l-system renderer to use curves which I think makes the trees look more natural. I also used the canvas wrapper to be able to get the position of the leaves as they are generated so I can animate them. Update: (23/9/10) Added hack to make leaves appear to collect on the ground beneath the trees.

Cloudy blue Perlin sky

Click on the image to load the canvas demo (requires FireFox or non-IE browser) Perlin Noise is a technique for generating procedural textures, commonly used for smoke, clouds or to add a random looking realistic roughness to surfaces. The algorithm is basically to generate noise, then scale that noise randomly across an image at different sizes and levels of transparency. This creates a self similarity which mimics the appearance of some natural processes. I found a canvas implementation by iron_wallaby and made the noise be the transparency of pure white, giving a cloud like effect. This was originally going to be just the background for another canvas demo I was working on, but that is delayed as I'm currently doing bioinformatics study/working on a project in my spare time. Things to improve on this are restricting how cloudy it is to a range, and removing some visual artifacts (lines/blockiness)

Diffusion limited aggregation

Click the image on the left to view the canvas demo. This is an example of diffusion limited aggregation - a natural process where randomly moving particles stick together, to form clusters. A good example is crystals. An initial seed is fixed in place, then particles are randomly moved around until they hit part of the main cluster, where they stick. This leads to a bigger cluster and feeds back on itself, producing a stochastic fractal (Stochastic means a random process) Code comments: I wrote this after looking at the C code for "diffuse.c" from The Computational Beauty of Nature (see books). An optimisation I copied from there is to constrain the particles to within 10 pixels either side of the cluster, to stop particles wandering off where they would never hit anything. This shouldn't have too much effect on the resulting graphics but is much faster (especially at the start)

Forest Night

The idea is you're lying on your back in a forest, looking at stars. Click the image on the left to view the demo. Press reload to view a different version. Written in Javascript / HTML Canvas (use Firefox, or anything other than Internet Explorer)

Field of flowers

 A field of flowers Click the image on the left to view the demo. Written in Javascript / HTML Canvas (use Firefox, or anything other than Internet Explorer)