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Author Topic: Aquatic Invaders  (Read 3486 times)

SeelenJägerTee

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Aquatic Invaders
« on: October 19, 2019, 04:14:38 am »

How does swimming work on invaders?
Can invaders dive? Let's assume I have a "floating" wall on top of a lake. Can and will swimming invaders choose to dive under it.

I used to wall off portions of the map to have safe access to wood and grazing fields.
Now that invaders can climb constructed walls, there is of course only one option remaining: casting my perimeter wall out of obsidian and smoothing it.
My current embark site is located on a lake. This raises a totally new problem: how far into the lake do I need to build the wall?
When an invader decides to swim around the wall. Is his capability to swim binary or gradual? What I mean is, will a swimmer get tired after a certain amount of tiles swum and start to drown? If so what are reasonably distances for swimmers to cover.
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Fleeting Frames

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Re: Aquatic Invaders
« Reply #1 on: October 19, 2019, 04:56:55 am »

Used to be that goblins' swimming mounts would take them into water, but they generally no longer have them.

Werebeast do attempt to sometimes enter forts through wells. This goes well until they turn back, whenupon they drown.

Undead will also enter through water sources, but they have [EXTRAVISION], which may mean they use combat pathing.

I don't know if swimming-capable invaders will swim in 7/7 water when they've yet to see an enemy. At the same time, you can't place your barracks on the lakeshore either, for fear of charging inside it.

(6/7 pools will often get frequented by visitors and in at least one case also invaders, though.)

anewaname

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Re: Aquatic Invaders
« Reply #2 on: October 19, 2019, 02:43:47 pm »

I suggest that if you have ramps in the water at the edge of the lake within your safe area, that you should remove them.

Observation 1)
Every creature except crundles seems to think climbing should be avoided at all times except "I see an enemy but I need to climb to reach it" and "I am drowning or starving, and climbing that wall will get me to where I need to go". 

Observation 2)
From observation, creatures will only choose to enter 7/7 liquid if they can breathe that liquid or do not need to breathe, and if that liquid will not hurt them. The ability to swim is not important, if you can safely walk on the bottom.

Putting those observations together, were-creatures, undead, and some titans will ignore water when looking for a path into your fort, but they are still looking for a walk-able path, not a path involving climbing. So, those invader types, which are actively attempting to path to the inside of your fort; they are willing to walk down a ramp into water, walk through the water under the floating wall, and walk up the ramp into your safe area, if that walk-able path exists.
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PatrikLundell

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Re: Aquatic Invaders
« Reply #3 on: October 19, 2019, 05:10:54 pm »

Well, there are natural climbers apart from Crundles (Troglodytes, for instance), but yes, most creatures climb only when prompted (including dorfs that climb to follow a path calculated earlier but no longer valid when they reach a point of change, even if there actually is a walking path that's only marginally longer).
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Sanctume

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Re: Aquatic Invaders
« Reply #4 on: October 30, 2019, 04:13:31 pm »

So a 3z "smoothed natural stones" (unclimb-able) well / cistern walls should be un-pathable and "safe" from non-flyers?

Code: [Select]
__o__   o = well
S~~~S   S=smoothed stone wall
S~~~S#
S~~~~~
######

PatrikLundell

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Re: Aquatic Invaders
« Reply #5 on: October 31, 2019, 06:48:40 am »

I've seen a report of an undead that managed to climb out of a smoothed natural stone moat after several years of attempts. However, I'd expect it to be mostly safe (but even then you may get a flying Titan that makes climbing irrelevant).

I don't know if anyone has made any rigorous testing of pitting natural climbers against smoothed stone.
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Atarlost

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Re: Aquatic Invaders
« Reply #6 on: November 01, 2019, 07:42:17 pm »

For wells you can use a U bend and grate such that the water pressure of your cistern pushes water through a grate and the well draws from the water above the grate.  Grates can't be targeted by building destroyers from below so can make entirely safe wells. 
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Nameless Archon

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Re: Aquatic Invaders
« Reply #7 on: November 14, 2019, 02:36:31 pm »

For wells you can use a U bend and grate such that the water pressure of your cistern pushes water through a grate and the well draws from the water above the grate.  Grates can't be targeted by building destroyers from below so can make entirely safe wells.
A small note here, unless it's changed: If there's an alternate, clear, walkable route to the object, it's dead meat, even from below. Per the wiki.
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Sanctume

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Re: Aquatic Invaders
« Reply #8 on: November 14, 2019, 02:51:48 pm »

For wells you can use a U bend and grate such that the water pressure of your cistern pushes water through a grate and the well draws from the water above the grate.  Grates can't be targeted by building destroyers from below so can make entirely safe wells.
A small note here, unless it's changed: If there's an alternate, clear, walkable route to the object, it's dead meat, even from below. Per the wiki.

I started using this scheme where 2 grates are between walls, so not access from either side without removing constructed wall.

Code: [Select]
############  #=wall   g=grate
__gCg_g# _~   _=floor  C=constructed wall
##^_^#^_^##   ^=ramps  ~=water source
#############

callisto8413

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Re: Aquatic Invaders
« Reply #9 on: November 14, 2019, 07:19:06 pm »

I use tiny drawbridges in the water tunnels I dig to supply my well.  Keeps the monsters out.
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