Generate large-scale structures

[Ralith]

One of the best ways to exhibit hyperbolic geometry is with structures that are impossible in euclidean space. We should extend worldgen to produce a variety of such structures, e.g. yendorian trees, whose branches don't decrease in size compared to their parent branch. These structures are characterized by being substantially larger than a graph node; think large buildings, cave systems, and megastructures. They don't necessarily have to be constructed from voxels.

The main challenge here is generating such features deterministically no matter how you approach them, and in defining complex, interesting hyperbolic geometry in a maintainable way.

[Ralith]

The main challenge here is generating such features deterministically no matter how you approach them

We can solve this the same way we generate the noise fields: place each structure 100% behind some inter-node plane with respect to the origin. The graph ensures that a specific node is always the first one populated behind any given inter-node plane, so that node can be responsible for deciding what (if any) large scale structure should be generated.