I've actually had this problem a dozen times in many different fortresses, and I'd assumed it's already been reported, but I didn't see it on the bug list nor in a forum search, and I've been hoping it would be fixed in the new release, so I'll do it now.
When I have a path like
_____ ___Goal
Start ____/ \_____/
My dwarves can never figure out how to do it. My "Control Rooms" for Lava and Water almost always have setups like these so they can seal themselves off at will, and still control the fortresses water and magma distribution - this may be affecting the pathfinding somehow, as there are usually a number of other (inaccesible due to liquids, locked doors, etc.) paths to the Goal location, since it is connected to the fluid systems that runs through the entire fort. What it means is that in order to get someone in the room, I need to guide a soldier one step at a time, and then seal off the room (he can leave, but not return).
I'm wondering if this is just an extension of the bug where dwarves have no problem pathing through liquids, but will refuse to walk through them, which results in hundred of "action canceled" messages if there is a pond with ramps anywhere in your fort, even when there is a clear route to their goal location.
That's not the only time I've had the problem though, and it doesn't explain the following situation (which might, admittedly, have a very different cause)
Addendum: Apparently the problem with the one below was the whole "Ramps don't work unless they are against a wall" thing, I think (though I no longer have the fort to test). I'll build a new one and test it later. That still doesn't explain the first situation, which had no ramps.
This has also affected some of suspended bottomless pit constructions as well... I once tried to make a secon that looked like, after having build the suspended platform and then disconnected it from the original tunnel. Dwarves could not figure out how to get on, which really messed up my collapse the pillar to drop the entire population into the pit during their party plan.
______________
Ramp/ | Stairs +
+_________ <-Suspended platform.
Anyways, I'm going to do more testing on exactly what triggers thus, unless it actually IS known and has been reported before, in which case I'd appreciate someone letting me know.
Author
Topic: [40d] Pathfinding error when need to go up, then down. (Read 496 times)