The idea of CA is to generate an array of states (pixels of an image) from another array of states using a specific function (a rule). The new array is called a next generation and is simply a next video frame. If you generate the frames constantly you will get an animation. A rule applies to every pixel of an image and usually depends on other pixels from a previous frame. The most popular CA rule is called Game of Life, a 2D binary array in which every pixels depends on its closest neighbours. In every frame and for every pixel you read its current state (0/1 or dead/alive), then count its alive neighbours (0-8) and due to the rule below you get a new state. Game of Life is just one of CA rules. CA can work with other range of states (ie. 256 values of gray) and in 1D arrays, 2D or 3D, or whatever you want. You can find some cool 3D examples in the web. It also doesn’t necessarily have to be squares.

Credits to graphic designer, and programmer KSAWERY KIRKLEWSKI for developing this Processing tool for generating images and videos based on Cellular Automata concept. Check out his website for more fascinating work.

Note: the code is open source, which means that you can use it freely with a proper credit.