Generating structures in a blocky world

[Aghostcat]

Is there an easy customizable way to generate structures out of voxels in blocky terrain like buildings, dungeons, towns, etc?
I've been looking at the generators and not sure if the way trees are made really apply here.

[MGilleronFJ]

No, there isn't. It's not always a trivial thing to solve, and not easy to make "built in" because it depends a lot on how you generate your base terrain in the first place. You have to come up with that. It might be a bit easier to do with a multipass generator (though it has relatively high costs to pay for that convenience). Otherwise you may exploit determinism and use seed/hashing/voronoi noise to determine deterministic points per chunk, which might be easier or harder to do depending on how you structure your base terrain (height-based? 3D noise?). Determinism-based methods have the best parallelism so they may be preferred, even if they lead to some redundancy (calculating the same structure multiple times in multiple chunks; the point being, chunks don't need to inter-access/modify each other, which is a threading nightmare), though they can be harder to understand. Or in the worst case, manage your own thread-safe data structures to "remember" where things should be as the world progressively generate around, at the cost of potentially worsening parallelism.
The only bits of docs I wrote about that is here https://voxel-tools.readthedocs.io/en/latest/procedural_generation/#handling-block-boundaries-with-voxel-structures