Yes, exactly. I will just use my games as an example.
Battlecruiser (which evolved to…) and Universal Combat, have a massive universe consisting of space, planets, moons.
There is no concept of “levels”
The entire world is generated using a script (which you can download and see if you have my scripting tools which I released on Steam for UCCE a few months back)
That script determines where everything in the “world” is. And there is one that is specifically for moon and planet positions and generation.
It runs at startup.
When a moon or planet needs to be “entered” from space, the script builds the surface from another script, creates the terrain from a height map, and then places objects (e.g. buildings) on it at positions defined by…again, scripts.
I developed that tech back in the mid to late eighties because I knew that procedural methods were going to be the only way for me - a sole developer - to build the world I envisioned. That, and the AI language I developed, contributed to the delays of BC3K because I was out of my league, having to invent everything on-the-fly.
Over the years, as tech improved, across various games, I continued to improve on it, ending up with Universal Combat which became the combined arms game with space, planet, vehicles, naval, fps etc. I was the FIRST to do it.
In Line Of Defense, I opted for level based world because it is a smaller game in which only the terrain benefits from procedural techniques. And that is exactly what Star Citizen is currently doing. Except that whereby my artists have spent the better part of 5 years handcrafting 13 (4 space, 4 stations, 4 planetary, 1 carrier) scenes/levels in a level editor, CIG has the arduous task of creating 110 star systems and 500+ planets and moons - in a level editor. By hand. And six yrs later, they don’t even have 1% of that world built. With the upcoming 3.0 due in July/Aug, they will have 3 moons. It’s hilarious.