On average though, people tend to have memory of where they've been, a sense of direction, and a sense of distance to be able to calculate the next logical step. You can also look out into the horizon to see if there's a wall to go around and deduce/remember which way the door is.
I find myself having to give directions on a regular basis. Perhaps the players of Dwarf Fortress are a cut above the rest, but most people are baffled by things like the name of the mall where they shop, the location of the only major roadway and the knowledge of where west is. And, having recently moved to an area with lots of twisting roads and no intersections I'm always baffled by the direction the sun sets at my job compared to my house. Now, do that underground in twisty little passages all alike. (Which I've also done.)
Dealing with a simulation like this, each dwarf has very little memory to remember routes like humans would. They rely on the engine to tell them where to go. The problem with markers is when you have none. The dwarfs would have to be able to navigate a little. If you can get them to nav a little, why not use that instead of engine tricks.
Because a) it takes extra memory b) by pathfinding common or difficult areas in advance we save all that repitition.
If you had a signpost mechanism that was updated every time something was built near it, then the dwarf would only need to find the closest sign to get directions. However, what kind of directions? Go west for workshops? What if you have workshops both ways? You'd have to recursively update each sign with directions on getting to the shop you just built. That means that every sign must be aware of that shop you just built and be able to tell a dwarf which sign to go to next.
No, you'd find the nearest sign to the dwarf and the nearest to the target and do a quick check to see if it's worth using the main route. When the route's off or not accessible then regular pathfinding takes over.
It's merely a hint to the computer so that it can save a few cycles without caching 4,000 routes and to control paths where geography might make it awkward.
For instance:
You build signs at every intersection.
You build another sign, workshop, designate a room, or storage.
The build function finds the closest sign and updates it with a reverse route to the sign/shop/room/storage.
That sign would have to update it's neighbors, and so on until every sign knew the location of that new shop.
a) Signs wouldn't know shops, only other signs b) Signs only update when there's time or as a byproduct or regular dwarf pathing. I'm sure there's some sort of neural net type terminology for the signs knowing each other and finding a route primarily through the nodes.
That's quite a bit of memory if you use the signs. If you don't use the signs, then how do the dwarfs know their way around? People don't need signs to get somewhere. Usually through trial and error you find your way. They also use markers to help them.
Actually, we have signs everywhere. Walk, don't walk, Main Street, Route 12, 23-86 South St., 6th Floor, Rooms 631-640 right, Suite 639: Ed's Tackle Inc., Ms. McReceptionist, Receptionist, Up, Down, Slippery When Wet. Large cities have signs EVERYWHERE (not counting advertising). Rural areas have signs all over the highway and filling every rest stop. And then we still have them on our mailboxes, cars, streets, schools, offices... The markers we mostly use are signs. Turn left at McDorf's, (the place with the big gabbro M sign). Even so, a statue or fountain could be just as effective a landmark, I'm merely using the term sign, perhaps station is more appropriate, but it evokes images of dwarves using minecarts for mass transit.
So why not have the dwarfs drop markers (virtually) after building a shop? When they finish building, they route the path back to the entrance and lay down markers? How do your dwarfs know it's an intersection and not a very big room, wide path or a turn?
They don't. They're dwarves. They charge naked to drink from carp rivers and let their puppies sleep on traps. And dropping all those markers goes back to the whole huge routing thing.
You could make a new skill called fortress cartography and have cartographers scout around your fortress looking for new mine shafts and update the maps in the great meeting hall. 
It's an alternative to the dead time solution. (I really would like DF to use the time while I scout and plan and examine and trade and use the facilities. It would be great if I could pause it to get some water and come back to find that everyone has reevaluated their tasks and routes and selected the best materials and routes.
It's a fun sort of problem though. 
That it is.
Just to clarify, signposts shouldn't be dropped at every intersection, that would make them street signs, good for RP, but maybe not for a system. More likely a signpost by the dining room, workshops, a back staircase which is being ignored, the preferred stockpiles...
McUrist is 103 squares from his bed.
McUrist is 23 squares from a sign and his bed is 14 squares from a sign, the path between is already done at 88 steps. (37 squares and 88 steps.)
Now 103 is less than 125 (37+88) but the 125 is optimised and doesn't need to be pathed except for the ends. (McUrist might also be entitled to a certain number of frequently used paths based on his intelligence (or cartography skill
), thus making smarter people potentially better performers. It might also be guarded, legendary and the 103 is a rough or straight line quick calculation. He'd likely take more or less the same route in the end only he might take a less effective route and take more time calculating it.
Now, McScrewed is 118 from a sign heading someplace 39 squares away (110 squares from a sign), but! McScrewed after pathing his little heart out flashes a ? while giant cave spiders eat him because the tunnels were all convoluted and the route he found with his dying breath is only 20 squares shorter. He should have taken the safe route and saved himself the ? time in the process.
Of course there could be a couple of options in the raws to tweak the sign functions. By raising a square length you can make known routes vastly favored over unknown and even drive dwarves to seek out established paths or choose stones nearest the "highway." Or by turning it down, the routes are little more than a hint.
Maybe someone can make up a basic map of an area in their own fortress with pathing difficulties we can use to discuss ideas?
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Topic: Route caching (Read 5900 times)