No Man’s Sky is an impossibly large game. You take on the role of a space explorer flying around a universe that’s filled with 18,446,744,073,709,551,616 unique planets, each possessing their own terrain, animals, and plant life. As Polygon points out, if you were to spend just one second visiting each, the journey would take you 584 million years.
And in fact, the studio behind the title–Hello Games–actually created virtual space probes to fly around the universe, make gifs of the planets, and report back to the development team because it’s the only feasible way to debug a small fraction of the universe.
Who would have thought that the largest video game ever made was crafted by a team of just a dozen, and only four designers? How could this be possible?
The short answer is that No Man’s Sky uses procedural generation, or mathematical formulas that draw mountains and quadrupeds. Each formula can use a few limited variables to produce limitless varieties.
The longer answer exists in the PBS explainer video above, and shines a lot more light on the process than just throwing the word “math” around. The game depends on L-systems, which were identified in 1968 by the Hungarian biologist Aristid Lindenmayer. He demonstrated that very complex algae or plant life could actually be broken down into relatively simple, fractal-like, branching structures. The easiest way to picture how an L-system works is simply to picture a tree.
I’ll let the video take it from here, but needless to say, the fact that the No Man’s Sky design team is using L-systems to such a wide extent, rather than coding 18 quintillion planets by hand, doesn’t cut down on its accomplishment. Because instead, the accomplishment here is digitizing the logic of mother nature herself.