(idea) Underground

[kerbiloid]

It's hard to implement caves and tunnels in KSP., that's given.

But as the KSP planets are scratchy spheres, what if invert such sphere by Kopernicus or so.
I.e. to get a hollow bubble world with solid sky.

Next step: what if place three concentric spheres.
Then we kinda get a regular planet surface, an underground solid sky (with its own stalactitish landscape), and an underground solid land.
All of them were planet-sized.

Also there is IVA mode in crafts.
What if instead huge labirinths make small IVA caves attached to the static objects.

[JadeOfMaar]

@kerbiloid Unfortunately I've come to shut down your idea. (I don't like to, and I've entertained the ideas of hollow worlds myself...but with my understanding of KSP, I only have negatives to respond with this time.)

The same thing that makes caves and tunnels virtually impossible in KSP...still remains, and other factors rise up to stand in your way.

Caves and tunnels only work on the outside of a planet because of the terrain collider (you cannot turn off pieces of it) and require custom hills, precise placement of them, and an exceptional amount of planning so that they can be made modular and can fit together nicely (like in the ancient Pipe Dream game (like Minesweeper for Win95) where you attach pipe pieces like puzzle pieces with the goal of completing a drainage system before the drainage itself reaches you and spills out). They need to be made so that you can tell where their openings are so you're less likely to block each other's pathways by placing a piece badly. (Their colliders will intersect and block each other).

Hollow worlds and winding underground paths are completely impossible because:

1. The PQS terrain system only allows you to carve the terrain outward or inward toward the planet's center and in no other direction at all.
2. You cannot selectively disable or hide terrain colliders. If you could, then whole squares (PQS tiles) would vanish, and you've seen enough terrain glitches to know what they look like. Also, whenever you're judged as undeground by physics, you get destroyed.
3. I can't imagine where the sky goes inside a hollow planet. As far as KSP physics is concerned, you're going to get something that looks pretty ugly, assuming it works.

Recursive/Concentric/Nested planets is a very, very bad idea. The PQS/terrain of only one planet at a time will be active and the others will not. They will be intangible and only their ScaledSpace will render. You also run the risk of inviting an SOI kraken-- Either a boundlessly powerful kraken that ejects you at light speed or above when you enter an atmosphere that does not belong to the same SOI; or the one that instantly destroys you when you land on a planet but its SOI edge is underground.

Dyson world physics is not present in KSP. There is no option to provide inverse gravity or bi-directional gravity (which pulls you properly from both sides of the hollow world surface) and make you stick to the ceiling inside a hollow world.

There are two mods that add parts that produce their IVAs underground but those only run on the idea of building a habitat into the surface (of the planet or an asteroid). And they are attached by claw or KAS. One is a WIP that fizzled out and the other is a feature of USI Asteroid Recycling Tech, but I don't know if that USI feature is still there or still works.

[kerbiloid]

Thanks..

Sad to hear, but nice to know.

[Apelsin]

Hopefully the terrain system in KSP2 is robust enough to allow 3d geometry with respect to the planet surface (unlike 2d for KSP). Always wanted explorable subsurface oceans for example.  In general, the more interesting terrain features there are the better the exploration aspect imo (tired of landing on a rocky grey surface and realizing that doing it again is pointless since the whole planet looks more or less the same).

PS: In the VAB screenshots for KSP2 released so far, there seems to be stuff related to radiation. If that's acually gonna be a gameplay aspect, caves could become very useful for radiation shielding of long term bases. Just a thought 

[wasml]

A modder who's name I can't recall was working on a mod (never completed unfortunately) that would have had a surface part with an IVA that would have been extendable. The extensions would have been IVA only and extendable to make underground bases. The plan was to allow the player to move between rooms by clicking on hatches to change IVA's. If I find the link I'll add to this post.

Found it:

 

Edited January 16, 2021 by wasml

[JcoolTheShipbuilder]

Unless you somehow make giant solid terrain scatters that cover the entire planet. But you still can’t have biomes above biomes.

[HyperDraco]

I 100% want this to be real.

I've been aching to build an underground missile silo.