I've been making fractal bedrooms for a while, and I've always been interested in ideas like making my whole fortress a hexagonal pod structure with my fortress descending from there, however, I'm becoming more and more obsessed with trying to find a way to make a serious three-dimensional fractal fortress.
That means the entire fortress would have to be a continuation of the same single pattern, including stockpiles, workshops, residences, dining hall, and trading area. (Outer defenses need not necessarily be part of the fractal, especially if I just dig a giant moat around the whole thing.)
Now, I know I can easily make a repeating tetrahedral structure, which would probably be impressive in its own right, but I'm wondering if there is something more challenging that is still possible to fit into a floorplan that could service a workshop.
One of the things I was thinking of doing at first, thanks to the lamia/naga mod I was working on, was making my fortress a giant Caduceus, with two hallways as "spines" of the snakes, and all of the actual rooms patterned as "scales" that come off that central helix of ramped hallways, with the smaller "tail" ends being more residential, and the larger scale sections being the workshops and stockpiles. However, I'm not sure how well I can actually manage to cram something into a broad enough fort to be useful, without making those snakes look ridiculously chubby and short for the space I have to work with. (Plus side of this, however, would be that it would come up out of the earth and be very photogenic in a way that a regular tetrahedral figure that remained completely underground would not be.)
The most complex ideas I have, however, are the "geode" or "spiral ball" formations, where I have a single "core" of my fortress, from which "crystaline" shaped rooms (parallelograms or hexagons repeating in outward concentric rings) that could spike outwards in ever-larger rings for the geodes. Spiral balls would be something like the helix pattern, but with four or more arms wrapping around the core in an ever-expanding spiral as the arms get "fatter" as they expand.
The major problem with the geodes and spiral balls, as wonderful as they would be in concept to see (although visualizers would probably have great difficulty actually making sense of them) would be that building long vertical shafts in regular shapes tends not to leave much living space since DF is unfortunately so fixated upon its silly fetish with horizontally-built rooms.
So, I'm basically asking for help coming up with ways to implement some sort of workable (non-square/cube based!) fractal three-dimensional structure that I can actually implement into a fortress, be that by helping iron out some of the kinks of some of these, or proposing other forms of fractal to try. (And this thread may as well act as a repository of those ideas, as well, for those looking for a more artistic fortress layout.)