10/15/2008: All right, sorting out the underground revisions... we'd like to get a framework in place that can recapture some of the better properties of the 2D version without conceding any ground. The general idea is to set up a few world gen params that will allow you to control the frequency and nature of underground features that you might encounter, especially as you mine in dwarf mode.
If many features are requested, they'd need to be arranged in such a way their discovery is inevitable while at the same time providing some breathing room for a fortress. So the first issue is that some (not most, fortunately) of the code still more or less has the map features stored as 2D rather than 3D objects, so that I can't currently layer features over each other. Once features can be placed over each other in 3D, we can have entire layers devoted to this and that, boxed in by this and that on their sides, twisted around with this, with that over there. So you'd hit something. I'm also planning to push more of it into the existing system (used for HFS) that creates units, items, fluids etc. as they are discovered to avoid FPS hits from the increased feature density.
Another issue present in 2D that is largely absent now are some interesting and long-lasting challenges from map features after (or before) they are discovered. Previously, you'd be attacked or otherwise perturbed by ambushing critters of various sorts. So we'll have that, at least what we had before. The gremlin needs to be your buddy again. And new buddies. It's no fun to spoil the specifics though.
There will have to be a lot of specific remodeling to facilitate this process. Chasms for example don't support creatures moving around as they stand -- a lot of the silliness like critters sitting on bizarre ledges for no reason will have to be changed. Features can't support populations versus your fortress properly if they don't have off-map access points (without something strange like monster generators), so more features will be large enough to make more sense that way.
Practically speaking, I'm going to start with the 2D -> 3D conversion and clean up some other code that'll allow me to add things easily and to add them over larger patches of the map than the single world map squares that are used right now. After that, I'd like to get it up to around the point of interest and excitement from the 2D version for thems that wants it, though as I mentioned previously, I'm only going to be working on this for long enough to get a framework established, then I'm going to go back and do the remaining work on this release in its proper order.
posted here for anyone that hasn't read them yet.
Adding a few things (like a lost world cavern entry that will incorporate some other mentions)
Edit 1:
Lost worlds will not likely get the Toad Stamp of Approval
TM in my opinion, since it requires the generation/coding of unique plants/animals/monsters for a rather rare event. Once "random creatures" is added, it might squeeze in. Just an opinion.
Now we have two explicit mentions of dinosaurs in the list (thus proving I don't edit out the ideas I don't like personally), so let's not bring that one up again, shall we?
The heavens/mood caverns etc were added in, even though they cross the stated intention line a bit IMHO. They have clear ties to other items in the dev notes, which is something I try (unsuccessfully) to avoid. Frankly I want to try to stay away from such additions because they are not
clearly UD. If we walk down that road, we could add any and all suggestions to this list by just appending "in a cave" to the suggestion.
Edit 2:
Fair warning to all those voting for UD. Since Toady is clearly implementing features from this list, the votes will be reset (after duly recorded on the OP for bragging rights). I encourage you to vote for UD again to keep it a priority issue, but also keep in mind that we need to try out all the new additions to the game, re-evaluate the non-implemented items, and get some new content before we rocket this back up the flagpole. Otherwise the whining will not end.
Anything implemented will be removed from the list, and stored in spoiler tags in the OP.
And I want to mention just how F-ing thrilled I am that Toady opted to restore the 2D feel of the mountain before adding new content. We had to take a step back to get 3D (which was worth it), but hopefully the mountain will regain its vicious demeanor.