O'Neal cylinder?

[grondilu]

Wouldn't it be cool to have this kind of world in minetest?

https://www.youtube.com/watch?v=UiO8CgGiWPM

I should be much easier to do than a spherical world, since a cylinder can be isometrically mapped to a plan whereas a sphere can't.

[paramat]

That's one of my favourite videos. You're in luck, my flexrealm mod is designed to create O'Neill cylinders, dyson spheres and ringworlds https://forum.minetest.net/viewtopic.php?id=7887
However gravity does not change direction, this is not yet possible in MT, however the lower 1/4 of the tubular realm still makes a good playable valley-like map, and climbing or swimming up the walls is a lot of fun.

[thetoon]

If we were able to increase dramatically viewing distance (probably through a LOD mechanism of some kind), it could be possible to simulate such curved setting with shaders. Since gravity is always locally perpendicular to the ground "plan" (its tangent plan when curved), even that would be right. The only missing piece would be "wrapping" two opposite sides.

Then, a glitch would remain : no matter how far up you'd build, you'd never meet the other side. But visually, it would work, with the added advantage (upon paramat's excellent flexrealm) of making gravity a non-issue.

[Sokomine]

If we were able to increase dramatically viewing distance (probably through a LOD mechanism of some kind), it could be possible to simulate such curved setting with shaders. Since gravity is always locally perpendicular to the ground "plan" (its tangent plan when curved), even that would be right. The only missing piece would be "wrapping" two opposite sides.

Exactly. A cube of 64 km in length is not that much, especially when applied to something with earth-like gravity. It would be great if the sky-background could be changed for some worlds to other backgrounds - i.e. that of a ringworld. That background area could never be reached - which in this case is even realistic.

[grondilu]

That's one of my favourite videos. You're in luck, my flexrealm mod is designed to create O'Neill cylinders, dyson spheres and ringworlds https://forum.minetest.net/viewtopic.php?id=7887

Awesome. I'm glad I'm not the only one who want this kind of stuff in the game. Hopefully they will be done eventually.

[paramat]

Minetest's mapgen dev (hmmmm/kwolekr) would probably say 'those things should be done by a mod', i doubt they would be added as a C++ core mapgen.

It would be great if the sky-background could be changed for some worlds to other backgrounds - i.e. that of a ringworld. That background area could never be reached - which in this case is even realistic.

This can now be done using the per player custom skybox.
The dimensions of Niven's ringworld would certainly make the local area flat:

[thetoon]

This can now be done using the per player custom skybox.

Sounds interesting. Means that even if we had a much bigger world, we could still "cheat" and use (externally) rendered pieces of it as skyboxes. Think : minetestmapper wrapped on the inner face of a ring, rendered in space and used as a skybox.