Langton's Ant is a two-dimensional cellular automaton with very simple rules, invented by Chris Langton.
The principle of its work is that a certain "ant" paints the current cell in a certain color and rotates 90 degrees according to a predetermined algorithm. The fill color and direction of rotation depend on the color of the current cell.
After a certain amount of seemingly chaotic movements, the "ant" begins to build an endlessly repeating road.
This is an implementation of this automaton for three-dimensional space.
What is Langton's Ant:
https://www.youtube.com/watch?v=1X-gtr4pEBU.
Download "Langton's Ant 3D" application for free on Windows, MacOS and Linux:
https://drive.google.com/open?id=1rWoRBUNSiwUK0WK2ZsJNOEdHomnI6LY0
or
https://yadi.sk/d/APsDNN3smWCrqQ