Okay, I can’t tell if this second cave system idea was edited in now or if it existed before, but I wanna talk about it. Or rather why it’s impossible to achieve.
Qbus’ original idea was simple and straight-forward - one-directional generated cave systems that are connected via code and finally there’s a boss.
What you are suggesting however is literally impossible to program. I mean, literally. There’s no way to do that in code without losing your sanity (and I’m a firm believer it’s unachievable).
First of all, you’d have to determine the ship’s angle relative to the cave system. Since they would be randomly generated, that would be impossible to achieve unless IA figures out how to rotate your ship such that it matches the direction of the tunnels - perhaps if tunnels are different parts. But then there’s another problem. Not even advanced games like Minecraft and Terraria that depend entirely on world generation have perfect cave systems. In fact, you might find connected caves in these games, but that’s entirely the result of RNG and not even an “intended” feature. A single continuous cave system created solely by random generation is impossible. There will always be dead ends, random holes in the terrain, other holes filled with water for example, etc.
That’s why IA can’t add such specialized cave generation. In CI5 it worked because planetary missions were hard-coded.
Now this isn’t supposed to be taken as offensive - not at all, I just explained why it can’t happen. But what about I do the opposite now - what about qbus’ post?
Well, number one, qbus’ cave generation would have only one direction - either left or right. That means only one angle to deal with. That eliminates 3/4 of our problems. As for how they would be connected, making straight linear caves is more than simple. It would be like a breeze in code. You arrange some parts randomly or create a per-chunk generator from scratch (whatever IA decides to do). In the first scenario, each pre-made part could simply be connected with terrain just like qbus proposed. In scenario two, chunks could be for example 128x128 pixels or 256x256 pixels and then do some dark ancient magic to make generation work. The first idea is much simpler, but idea #2 isn’t too impossible to implement.
EDIT: If you guys remember qbus’ suggestion about manual spacecraft angle control:
The second proposed cave generation system might become a tiiiiny bit more doable, especially if it controls the direction you’re flying in. In that case angles might not pose such a threat, but like I said, such cave generation might still be really really hard to make.
I’m saying manual rotation could be indigenous only to such planetary missions by the way.