Eli5: How can games like minecraft or no mans sky be essentially infinite, yet take up a very small amount of storage?

Question

No mans sky is like 18GB or so on my PS4, yet there are 256 galaxies and literally around 18 quintillion planets. It can be played completely offline too, so it isnt coming from some server somewhere

I understand they’re procedurally generated, so they dont even exist until you pass through that area, but even after playing for countless hours and crossing thousands of miles of landmass, the save file is still extremely small

In: 1323

Answer 1

Procedural generation is fun.

Basically, you have a system for generating random worlds. You give the system a starting point (a “seed”) and it’ll always generate the same random numbers, which means it’ll also always generate the same map from that seed.

If you can guarantee that you always generate the same map every time, then you can just store that seed and generate stuff on demand. Then you save only the stuff that the player modified.