Headline:A lot on my plate with a lot of plates
Date:Tuesday, May 07, 2019
Posted By:Plaid Hatter Games

It's a week later, and I've done exactly what I talked about in my prior post (Working Towards a Plate Model (or... how to lose a dimension without really trying)).

And, of course, as soon as I was making pretty pictures I had to keep tweaking, and keep tweaking. The result is a 1401 line script that generates a 69mb sqlite file. The Iliad is comprised of a total of 251 levels (between the 6 spheres and the spine). I haven't worked out compartmentation for the disc yet. I'm not 100% convinced the player needs the spine layout either, but there may be a reference to an alarm in the docking bay, a drone launch, or meteorite crashing through the armored upper hull.

The spine is considere mostly uninhabited by man. The layouts look a bit like this at the thin parts:

And up in the armor section, it spans the entire radius of the vessel (image is scaled because the vessel is 440m across at this point):

I also injected a little more engineering into the design. I had originally though that 314 square meters as target size for a compartment was a cute rule. The problem is that when you are laying out agricultural fields, or shopping centers, or recreational facilities, it is nice to provide as much open space as possible. In a perfect world I could say that an entire deck is magically self-supported by it's anchor to either the core of the sphere or the shell. And actually, I do that for the sky domes on the upper levels of sphere. (They don't have to actually support anything above.)

But for everything else, I need to interrupt wide open expanses with occasional structure to support the floor above. One approach would be to painstakingly construct the entire ship, evaluate the stresses, and reinforce where needed. But I would actually like to finish with the design work. Maybe even in one human lifetime.

The other is to look for similar structures and try to develop some design rules that they found. In my case, there is a wonderful structure in Pittsburg, Pennsylvania called the U.S. Steel Tower. It's has two remaining claims to fame. One has to do with they way they use liquid to fireproof the structural steel. The second is that it has the largest flat roof of any skyscraper in the world.

This building is actually a better design template than even the books on Naval Architecture I keep stealing from my coworkers. Ships, even Aircraft Carriers, are large in the horizontal and comparatively short in the vertical. (Nimitz Class, length: 333m, levels: 17). Skyscrapers tend to have a comparatively small footprint, with a lot of height. In truth the habitation spheres need elements of both, because they are both wide and tall steel structures. But most of the problems come from the height, because each level below needs to support the weight of the deck above.

What makes the U.S. Steel tower really interesting from a structural standpoint is that they built it as tall as they could build it, and no higher. They were content to let the building "only" be 64 floors. And that design decision was mainly to allow them to carry the same template from floor to roof. Also, because it is only 64 floors, it didn't need extra stiffness to counter the wind. The main driver of structure for both the WTC and Empire State Building was not the weight of the building, but the effect of the winds aloft.

The reason this building could have a flat roof has everything to do with carrying that uniform structure throughout the entire building. And if that was not enough, I also can see pictures of the building under construction, and get a rough idea of how it went together.

I'm not asking how much steel I need. Or the shape of the girders. I just need to know what is the largest floor area that I think can be supported by a steel frame. And because the building is uniform, we can basically divide the total advertised square footage (217,045.0 m^2) by the number of floors (64), and from the picture I see:

(Archived from http://images.skyscrapercenter.com/building/us-steel_ext-constructionaerial_(c)leslieerobertson.jpg)

That the framework of the building divides each floor into essentially 4 tiles. From the picture we see 1 square tile in each pillar, and then a triangular tile that is roughly the area if one of the pillar supported floor areas. When I crunch all of those numbers I get: 217,045/64/4 ~= 847 m^2.

Keeping each compartment to less than 847 m^2 assures that an engineer doing the proper structural calculations can have a decent chance of making this design work some day. The rule for the ship is that below the recreation deck (the "roof"), we can't have a room larger than 847 meters squared that isn't broken up by boundary of some sort. Those boundaries define where we can expect to lay in whatever girders, trusses, and whatnot to support the floor above. Maybe the boundary is an actual wall. Or maybe it is just spot where the ceiling dips down to make way for a girder. These structural hard-points make a logical place to divide up the ship.

You may have also noticed, colors! Yes, I'm feeding all of these wall vectors into a tool that can walk around the edges and form polygons. For the present, I'm content to live without breaking those polygons down any further into convex polygons or unit movement tiles. I can build a rudimentary routing model just from the information I have now. Each compartment is tagged with a usage code. One of those codes (P) indicates that the use is "Passage". The design math I developed ensure that every compartment touches a passage on at least one wall. If we assume that there is an entrance on any wall that touches a passage, I can use that rule to form a Dykstra's Rule based model for movement on one floor, and then make a special rule for how to jump between floors at elevators and stairs, and how to jump between spheres from the two tunnels on either end of main street.

But without further Ado, here is my highlights from the new model output:

The recreation spaces in between rings of the residences are essentially a shared back yard/park. In the commercial areas, those are open areas on upper floors to give you that canyon effect in shopping malls.

But the hard part is done. I have a complete high-level map of the ship. I can at least trace routes and measure the distance the character would have to travel to get places. As I create parts of the setting, I can tie them to a specific compartment. With many of these compartments being a good quarter acre in size, there could be several "settings" in one compartment.

Going back to my thoughts on Gilgamesh, I don't feel the need to be super-super detailed about the layouts in any particular compartment. If you go to the Doctor's office, you don't care so much about which exam room you are in. There can be logical spaces that the story makes up on the fly and connects in ways that are ephemeral and ploy driven.

Ok, now I'm off to start crafting some adventures.