Bay 12 Games Forum

Please login or register.

Login with username, password and session length
Advanced search  

Author Topic: Strange pathing issue  (Read 772 times)

Libash_Thunderhead

  • Bay Watcher
    • View Profile
Strange pathing issue
« on: March 17, 2019, 03:26:12 am »




They won't build the two walls, unless I built stairways/floors next to them. Why?
Logged

PatrikLundell

  • Bay Watcher
    • View Profile
Re: Strange pathing issue
« Reply #1 on: March 17, 2019, 04:48:48 am »

Building requires the availability of a building location at the same level as the building site located perpendicular to the site. You can often see dorfs building while standing on a down ramp or diagonal to the site, but they are unable to do that unless they could have stood perpendicularly to the site and at the same level. The one exception to this is that dorfs can build stairs in the same tile they're standing on.
Logged

Libash_Thunderhead

  • Bay Watcher
    • View Profile
Re: Strange pathing issue
« Reply #2 on: March 17, 2019, 05:50:01 am »

But the two walls in the picture has their perpendicular tiles available(north or south).
Logged

PatrikLundell

  • Bay Watcher
    • View Profile
Re: Strange pathing issue
« Reply #3 on: March 17, 2019, 08:12:16 am »

But are those locations reachable through a valid path? I don't use character "graphics" myself, and so have some difficulties interpreting the image. I remember I've made the mistake not to create an Up stair at the bottom of stair cases a long time ago (the rest must have been built from above, without me noticing that I'd screwed up).

One way to test pathability is to station a militia squad at the trouble location (that won't help detecting burrow issues, of course, as squads aren't bound by burrows).
Logged

Loci

  • Bay Watcher
    • View Profile
Re: Strange pathing issue
« Reply #4 on: March 17, 2019, 12:46:56 pm »

For the top wall, the ramps are likely to blame. Dwarves cannot build a wall from the bottom of a ramp, and if their selected path does not provide an adjacent tile to stand on they won't be able to perform the job. You can use traffic designations to encourage them to approach the job site from a suitable direction, or just remove the ramps to force the same.

For the bottom wall, there are no problematic ramps shown. Did you chop down a tree in that area? Due to a bug, removed trees don't properly clear all their pathing information, which can cause obviously-accessible tiles to be treated as inaccessible. Other options include a hot tile with temperature calculations disabled, burrow restrictions, or inaccessible building material.
Logged

PatrikLundell

  • Bay Watcher
    • View Profile
Re: Strange pathing issue
« Reply #5 on: March 17, 2019, 04:33:21 pm »

My experience with the cut down tree issue is that saving/loading solves that issue, at least that's been the case when it's happened to me with the current version.
Logged

Libash_Thunderhead

  • Bay Watcher
    • View Profile
Re: Strange pathing issue
« Reply #6 on: March 17, 2019, 06:59:18 pm »

Yeah, I think the trees are to be blamed.
I recall before I built the stairs, the wall couldn't be placed, it showed no access to building materials. I didn't give that too much thought. It seems the stairs solved the problem, partially.

By the way, is there a way to recalculate all the pathing informations? Like, a dfhack command?
Logged

Sarmatian123

  • Bay Watcher
    • View Profile
Re: Strange pathing issue
« Reply #7 on: March 18, 2019, 06:57:12 am »

You should always clear trees all around the construction. Inside and outside. If you construct floor on one side of the wall, then construction will go faster and there should be no problems with pathing. Because of the dodging bug, which can teleport some fighting creature inside your fortress, through dodging mechanics, I would also suggest constructing double walls.
Logged

PatrikLundell

  • Bay Watcher
    • View Profile
Re: Strange pathing issue
« Reply #8 on: March 18, 2019, 07:48:51 am »

You CAN destroy saplings before they mature using dirt road designations, but typically you just cut and build, which can catch you off guard when a sapling matures (especially if building activity is suspended due to hostile action and resumed only when the area is safe again).
Logged

anewaname

  • Bay Watcher
  • The mattock... My choice for problem solving.
    • View Profile
Re: Strange pathing issue
« Reply #9 on: March 18, 2019, 10:32:40 am »

By the way, is there a way to recalculate all the pathing informations? Like, a dfhack command?
Probably not, but there isn't enough a need for it. Usually there is another path that the dwarfs can take, so you never notice the problem existed, and then it goes away during some save because you have real-life stuff to do. I only noticed the problem once in my forts.
Logged
How did I manage to successfully apply the lessons of The Screwtape Letters to my perceptions of big grocery stores?