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Author Topic: Merchants and Waterfalls  (Read 1120 times)

niteblade

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Merchants and Waterfalls
« on: November 14, 2012, 04:52:50 pm »

So I am a relatively new player to DF. Have had a few Fun fortresses but I have a solid one set up now so the Fun has been reduced. My embark site has an interesting natural waterfall which creates a convenient canyon. However, the river sweeps lots of things over the falls (dwarves, goblins, merchants, etc).

I have a question about a Merchant Mishap that just occurred: My trade depot is accessible. The human caravan showed up and was taking its sweet FPS-death-kittens time to get to my depot. I wasn't paying attention to them, as I was stationing my troops for the inevitable goblin incursions when I happened to take a casual look at the unit list. Two of the merchants had the tell-tale BLUE OMG DROWNING highlight on their names and I noticed... yep they went over the falls. Which are no where near the caravan.

Did the unfortunate (drunk) merchant and his mule just path straight into the river? Why would he do that?
The caravan immediately started leaving. Are there repercussions for this? Is there a way to prevent drunk-swimming in the future? If not, is there a way to trade for the booze the humans must be drinking?

Here is a link to a screen shot to illustrate what I am talking about:
http://i.imgur.com/D2zX0.jpg

On another note, Vampire diplomat from the humans? Does this do anything bad?
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Imp

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Re: Merchants and Waterfalls
« Reply #1 on: November 14, 2012, 05:13:01 pm »

When the game spawns a merchant, it checks for possible paths to your depot as of that instant.  Your merchants will spawn at a map edge that somehow allows a path to your depot (packbeast merchants will still spawn with a complaint if there's no possible path to the depot).

Merchants want to take the shortest possible path to your depot.

The image you posted shows that from where you mark the caravans as coming from, they can go a longer path across that safe bridge, or, IF the water happened to have been shallow enough at that waterfall as of the moment they spawned, they could take the shorter route across that shallow water by the waterfall into your fortress where I assume your depot is.

Merchants will never choose to take a longer path.

They do get a saving throw - if their chosen path becomes blocked (waterfalls randomly have different quantities of water, and will randomly not offer a path anymore) then they will choose another.  Unfortunately, they only recheck pathing occasionally, but that may have saved some of your merchants.  The ones that died there attempted to path through the water and its varying depth and constant flow carried them over the fall.

To fix this, ensure that there are only 100% safe paths to your depot.  Some players make an 'airlock' or a 'hidden merchant path' with raising bridges to block off the depot from the rest of the map (including most of the fortress) and allow only a very small pathing area to that place, so that merchants are forced to spawn in a very controlled place to reach the depot - once there, bridges are lowered to allow the dwarves to reach the depot for trading.

As to the diplomat, I don't know if a visiting vamp CAN feed, but I wouldn't want it to hang around just in case.  Make sure your leader has free time so that meeting can happen and be concluded quick quick, to be on the safe side.  In any case, vamps are only dangerous to currently unconscious dwarves... be prepared to seal off the bedroom part of the fortress if needed to block the vamp.
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niteblade

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Re: Merchants and Waterfalls
« Reply #2 on: November 14, 2012, 05:31:48 pm »

Thanks for the information! This is definitely what happened. I can imagine the poor drunk merchant seeing the shallow water, not noticing the falls and thinking "suckers in the wagon gotta go all the way around. he he." Dead. I feel more sad about the mule.

Well, I will consider merchant manipulation but I think part of the Fun of this game include flavorful events like unsafe river crossings. Maybe I will make a bridge over the water that is closer to my entrance gate. By the way, when the water freezes in the winter, the icy bottom of the falls can be mined out for all sorts of goodies

Also, the depot is located down a ramp one z-level below the surface. 

Keeping my eye on the vampire diplomat now. Fortunately, my count has little else to do...
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Sutremaine

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Re: Merchants and Waterfalls
« Reply #3 on: November 14, 2012, 09:57:26 pm »

The image you posted shows that from where you mark the caravans as coming from, they can go a longer path across that safe bridge, or, IF the water happened to have been shallow enough at that waterfall as of the moment they spawned, they could take the shorter route across that shallow water by the waterfall into your fortress where I assume your depot is.
It's odd that it's doing that. The water at the ramps is 6/7 or 7/7, and there isn't any 3/7 or shallower water for a couple of tiles beyond that.

Does anything ever interrupt the water flow? Reducing the amount of water reaching the waterfall will reduce the water level next to the drop, possibly to the point that the water level at the crossable points drops to 3/7 briefly. Either way, you can put floors down at ground level where the downramps are. That'll cut off access even with no water at all in there, because it blocks the ramp exits. Or you could extend the western wall down three tiles, which will turn the area east of the waterfall into a dead end.
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GreatWyrmGold

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Re: Merchants and Waterfalls
« Reply #4 on: November 14, 2012, 09:59:00 pm »

It looks like the water at the end of the waterfall is only 2-4. What version was the world generated in?
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niteblade

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Re: Merchants and Waterfalls
« Reply #5 on: November 14, 2012, 10:20:40 pm »

I am running the most recent version, 0.34.11
When i watch the water at the very end of the waterfall, their are brief moments when all four of the river width tiles become 1 or 2 deep (or less). It lasts for maybe one.. step? (how are those called?) After which 3's and 4's (depth) will again be present.

Quote
Does anything ever interrupt the water flow?

No, save for when it becomes ice in the late fall.

Quote
Either way, you can put floors down at ground level where the downramps are. That'll cut off access even with no water at all in there, because it blocks the ramp exits. Or you could extend the western wall down three tiles, which will turn the area east of the waterfall into a dead end.

Ehhhh I think I may leave it be. I have had numerous traders come from that side (western side) of the map and this was the first time one of them decided to take a swim. Plus goblins sometimes try to path over to me from that side and, from what I can tell, they enjoy a nice refreshing dip  :P  I have the wall go to the chasm which acts as a natural barrier. The river freezes in the winter time (as does the gold mine at the bottom of the falls).
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niteblade

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Re: Merchants and Waterfalls
« Reply #6 on: November 14, 2012, 10:44:32 pm »

Dwarven Caravan just arrived... I am watching a couple of the merchants path towards their doom as we speak!  :o
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Sutremaine

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Re: Merchants and Waterfalls
« Reply #7 on: November 14, 2012, 10:45:05 pm »

I am running the most recent version, 0.34.11
When i watch the water at the very end of the waterfall, their are brief moments when all four of the river width tiles become 1 or 2 deep (or less). It lasts for maybe one.. step? (how are those called?) After which 3's and 4's (depth) will again be present.
Does the part you're looking at have any ramps? The screenshot looks as though the six tiles closest to the waterfall on each bank have no ramps on them, which makes that section of river sheer-sided. To get to that shallow water they need to find a ramp to descend, and those should all be covered by 4/7 or deeper water.

(on preview)

Watch where they enter the river.
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I am trying to make chickens lay bees as eggs. So far it only produces a single "Tame Small Creature" when a hen lays bees.
Honestly at the time, I didn't see what could go wrong with crowding 80 military Dwarves into a small room with a necromancer for the purpose of making bacon.

Imp

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Re: Merchants and Waterfalls
« Reply #8 on: November 14, 2012, 10:52:01 pm »

I am running the most recent version, 0.34.11
When i watch the water at the very end of the waterfall, their are brief moments when all four of the river width tiles become 1 or 2 deep (or less). It lasts for maybe one.. step? (how are those called?) After which 3's and 4's (depth) will again be present.

Any depth of water between 0 (dry) and 3 is considered pathable.  A dwarf that finds itself in a 4+ depth of water will immediately cancel their previous tasks and do a pathing check for a 'nearby' way to get out of 4+ deep water.

Merchants appear to do a single pathing check when they spawn, and then periodically and very randomly recheck their path.

An easy way to test the timing of various creature's pathing checks is to know something about their route and then block a part of that route.  Many, many creatures will continue moving along their previous route.  Sometimes they go all the way to the blockage before 'appearing to notice'.  Occasionally they 'appear to notice' and either create new pathing, or stop because they have no pathing, depending on how you blocked their route.

Probably the most commonly observed pathing tests come when a player chooses to 'turtle up' during a siege.  Watch your enemy after the path is closed - there's a lot of pathfinding timing being shown in what those critters do then.
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niteblade

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Re: Merchants and Waterfalls
« Reply #9 on: November 14, 2012, 11:13:11 pm »

Ok so here are some screen shots.

Quote
Does the part you're looking at have any ramps? The screenshot looks as though the six tiles closest to the waterfall on each bank have no ramps on them, which makes that section of river sheer-sided. To get to that shallow water they need to find a ramp to descend, and those should all be covered by 4/7 or deeper water.

This is a fair point so I checked and I was surprised by what I found.

Here the merchants approach the river, oblivious to their upcoming doom. Z= 0
http://i.imgur.com/dpGl4.jpg

Here is a view of the riverbed from Z= -1
http://i.imgur.com/a6i7T.png

Interestingly, as noted above, the ramps DO NOT exist for entry into what other posts have noted as "shallow" water

Here the merchants enters the water. His camel seems a little hesitant.
Z= 0 : http://i.imgur.com/xHBfE.jpg
Z= -1 : http://i.imgur.com/T1aol.png

Camel is in too, but the guard has stopped...
Z= 0 : http://i.imgur.com/uVEyq.jpg
Z= -1 : http://i.imgur.com/EKdkl.png

Valiant, if also stupid, attempt at fording
Z= -1 : http://i.imgur.com/Aqv4X.png

Alas the poor merchant finds himself in the Fun zone

Z= -12 : http://i.imgur.com/BApLy.png

--

The other merchant is about to do the same but the guards have stopped.
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niteblade

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Re: Merchants and Waterfalls
« Reply #10 on: November 14, 2012, 11:20:08 pm »

And welp. All the merchants decided to beat it immediately after that one fell to his doom. I guess I am going to have to do something about this after all :(
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vanatteveldt

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Re: Merchants and Waterfalls
« Reply #11 on: November 15, 2012, 01:55:34 am »

Since your river freezes over in winter, you can do some waterworks without too much fun.

I would remove some more ramps close to the waterfall, like 10 tiles or so using d-z after removing the ice. As said above, they won't path over a sheer drop, so this should solve your issues.
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AutomataKittay

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Re: Merchants and Waterfalls
« Reply #12 on: November 15, 2012, 02:19:57 am »

Bridge over the low water part! It'll at least give them safer route even if it's the same
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