Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[John Gaden]

It's a bit of a long winded story, so just bear with me.

Alrighty, so i had set up a nice channel from the outside river to my fort, and had set up a room for farming and everything. I'd just survived the winter, and it was as if one of my dwarves felt like it was his responsibility to take over starvations job and end my game. I ordered the opening of the flood gate to the farming area, and all was going well until the dwarf's dog just had to get in the way. At the same time as the dwarf pulls the lever, his dog has a puppy, whom suddenly charges into the farm and unleashes a flood into the rest of the fort. Only one main door between the outside and my fortress  prevented the water from spilling out into the wilderness. So i let the dwarves inside drown, giggling all the while, then proceeded to have the main door to the fortress removed, thinking that the water would just spell out and go away much in the same manner a cave-in acts. Much to my surprise, once the door was removed, the channel emptied the river into my fortress, and subsequently out into the wilderness. Okay, so i flooded the entire wilderness. At first thought, neat. Then i watched the flood, and it eventually started bouncing back and forth between the edges of the map and causing terrible lag. I watched it bounce around for a few minutes, then closed the game because my cpu was really crying.

Albeit very entertaining, it seems like this could be a serious problem, making accidental fort floods almost impossible to correct.

[Dehydration]

Yeah. Judging from other threads, this is an unintentional side-effect of the facts that it really wasn't intended for people to be able to use the outdoor river for farming (water isn't supposed to go uphill to the mountain, apparently) and that channels from the outside river contain an arbitrarily large amount of water.

But then, I'm sure you already noticed the second part, heh.

[John Gaden]

Yea, what was particularly interesting though was the behavior of the water. Im assuming it might have just bounced around the map for as long as i let it run. Perhaps a sort of diminishing value should be added to the water, to simulate soaking into the dirt or some such nonsense.

[John Gaden]

Also, after thinking about this more, it should be possible to duplicate the same bug using the fort river. If i were to just construct a floodgate near the river into a small room, let it flood, open the door, let my fort flood, and then remove the door to the fort...?

[RPB]

Yes, when you open a floodgate the water floods everywhere it can get to and doesn't recede until you close the floodgate.

[Toady One]

The "bouncing" and the lag are parts I'm not aware of.  The flooding of the inside is intentional, but the flooding of the outside is a bit strange, since the first big flood you get from the main river soaks up outside.  When I've flooded the outside map in the past, there wasn't an associated lag, and it just filled up.  The bouncing effect is from it crossing the fords and the coming back up the edge, if that's what it was.

[Insalubrious]

I basically just replicated this bug on accident with the following setup.  Now I can't do anything to stop the flooding, although nobody outside is drowing, which I find odd.  Here's a screen shot:

   

Edit: I figured out that if you put a stone pile outside of the door, you can walk in and out without flooding the fortress.  Is that intentional?

[ August 16, 2006: Message edited by: Insalubrious ]

[Toady One]

This is part of water not flowing "up hill"  into the fortress (not sure how the stone pile is related), which I guess I'll change but I'm not certain about how things should work -- you should be able to flood rooms and a good part of your dungeon, and calculate how far the water is from a river isn't easy without using more memory because it might be sourced from multiple points.  The reason the flood doesn't recede is because once it touches the outside river it considers itself "sourced" and so won't die down.  This should probably be changed, but there are many complications because floodgates all fake a Z coordinate change attributing it to dwarven talents with this kind of thing, so some internal contradictions can arise.

All water flows outside are considered at a low-level (non-drowning), except possibly those in channels (and the main river).