0001227: Some world gen mountains halls are inaccessible, possibly caused by erosion

Notes
(0003851) Footkerchief (manager) 2010-04-16 08:51 edited on: 2010-04-16 08:51	It would be helpful if you could name a particular site in that world that is known to demonstrate this problem. Otherwise, Toady will have to waste time guessing.

(0004002) Yaant (reporter) 2010-04-17 15:44	Hm, I've tried to recreate that world on my home WinXP machine to check site names, but got quite different world using same seeds (originally it was created on work Win2000 machine). Though it could be some mistake on my part, would have to recheck seeds when I'll get to work on Monday. Meanwhile I'll try to reproduce the problem on some smaller worlds, if I'll be successful, then would post seeds and site names here.

(0004231) Yaant (reporter) 2010-04-19 08:13	Oops, it turned out that I've tweaked some default worldgen options and forgot about it, so it explains getting different worlds. :) Here's the full world_gen_param.txt then: Created in DF v0.31.03. [WORLD_GEN] [TITLE:LARGE REGION] [SEED:3894293870] [HISTORY_SEED:2262357010] [NAME_SEED:3735191706] [CREATURE_SEED:2116295528] [DIM:257:257] [EMBARK_POINTS:1274] [END_YEAR:1050] [BEAST_END_YEAR:300:80] [REVEAL_ALL_HISTORY:1] [CULL_HISTORICAL_FIGURES:1] [ELEVATION:1:400:800:800] [RAINFALL:0:100:400:400] [TEMPERATURE:25:75:400:400] [DRAINAGE:0:100:400:400] [VOLCANISM:0:100:400:400] [SAVAGERY:0:100:400:400] [ELEVATION_FREQUENCY:1:1:1:1:1:1] [RAIN_FREQUENCY:1:1:1:1:1:1] [DRAINAGE_FREQUENCY:1:1:1:1:1:1] [TEMPERATURE_FREQUENCY:1:1:1:1:1:1] [SAVAGERY_FREQUENCY:1:1:1:1:1:1] [VOLCANISM_FREQUENCY:1:1:1:1:1:1] [TITAN_NUMBER:33] [TITAN_ATTACK_TRIGGER:80:0:100000] [DEMON_NUMBER:60] [GOOD_SQ_COUNTS:100:1000:2000] [EVIL_SQ_COUNTS:100:1000:2000] [PEAK_NUMBER_MIN:50] [PARTIAL_OCEAN_EDGE_MIN:0] [COMPLETE_OCEAN_EDGE_MIN:0] [VOLCANO_MIN:15] [REGION_COUNTS:SWAMP:1032:7:3] [REGION_COUNTS:DESERT:1032:5:3] [REGION_COUNTS:FOREST:4128:13:12] [REGION_COUNTS:MOUNTAINS:8256:9:2] [REGION_COUNTS:OCEAN:8256:7:0] [REGION_COUNTS:GLACIER:0:0:0] [REGION_COUNTS:TUNDRA:0:0:0] [REGION_COUNTS:GRASSLAND:8256:13:7] [REGION_COUNTS:HILLS:8256:13:8] [EROSION_CYCLE_COUNT:250] [RIVER_MINS:400:400] [PERIODICALLY_ERODE_EXTREMES:1] [OROGRAPHIC_PRECIPITATION:1] [SUBREGION_MAX:2750] [CAVERN_LAYER_COUNT:3] [CAVERN_LAYER_OPENNESS_MIN:0] [CAVERN_LAYER_OPENNESS_MAX:100] [CAVERN_LAYER_PASSAGE_DENSITY_MIN:0] [CAVERN_LAYER_PASSAGE_DENSITY_MAX:100] [CAVERN_LAYER_WATER_MIN:0] [CAVERN_LAYER_WATER_MAX:100] [HAVE_BOTTOM_LAYER_1:1] [HAVE_BOTTOM_LAYER_2:1] [LEVELS_ABOVE_GROUND:15] [LEVELS_ABOVE_LAYER_1:5] [LEVELS_ABOVE_LAYER_2:1] [LEVELS_ABOVE_LAYER_3:1] [LEVELS_ABOVE_LAYER_4:1] [LEVELS_ABOVE_LAYER_5:2] [LEVELS_AT_BOTTOM:1] [CAVE_MIN_SIZE:5] [CAVE_MIN_SIZE:5] [CAVE_MAX_SIZE:25] [MOUNTAIN_CAVE_MIN:100] [NON_MOUNTAIN_CAVE_MIN:200] [ALL_CAVES_VISIBLE:0] [SHOW_EMBARK_TUNNEL:2] [TOTAL_CIV_NUMBER:50] [TOTAL_CIV_POPULATION:30000] [PLAYABLE_CIVILIZATION_REQUIRED:1] [ELEVATION_RANGES:8256:16512:8256] [RAIN_RANGES:8256:16512:8256] [DRAINAGE_RANGES:8256:16512:8256] [SAVAGERY_RANGES:8256:16512:8256] [VOLCANISM_RANGES:8256:16512:8256] Problematic site is Atisalil, "Stakeglee", a mountain fortress Anyway, I got an idea what can be possibly causing the site inaccessibility: erosion. During my experiments with small worlds I've noticed that quite often mountain hall could be accessed only at one single land square (usually at corner), all squares around the mountain halls being somewhat lower. So if enough years passes after construction of mountain halls, erosion could lower the ground there, rendering the site inaccessible. It's just a guess, of course, but at least it would explain, why I wasn't able to reproduce the problem on small worlds -- by default generation stops too early for erosion to do it's job. So it could be important to wait all 1050 years of worldgen to reproduce the problem.

(0004241) Footkerchief (manager) 2010-04-19 09:47	Cool, thanks for the thorough followup!

(0015640) Footkerchief (manager) 2011-03-01 14:05	Mountain halls don't exist at all anymore, and will probably be drastically different when they come back, so I'm marking this report as suspended.

Issue History
Date Modified	Username	Field	Change
2010-04-16 03:45	Yaant	New Issue
2010-04-16 08:51	Footkerchief	Note Added: 0003851
2010-04-16 08:51	Footkerchief	Note Edited: 0003851	View Revisions
2010-04-16 08:51	Footkerchief	Note Edited: 0003851	View Revisions
2010-04-16 08:52	Footkerchief	Issue Monitored: Footkerchief
2010-04-16 08:52	Footkerchief	Relationship added	related to 0000688
2010-04-16 08:57	Kennel	Tag Attached: adventure mode
2010-04-16 08:57	Kennel	Tag Attached: Dwarf
2010-04-16 08:57	Kennel	Tag Attached: worldgen
2010-04-17 15:44	Yaant	Note Added: 0004002
2010-04-19 08:13	Yaant	Note Added: 0004231
2010-04-19 09:47	Footkerchief	Note Added: 0004241
2010-04-21 12:14	Footkerchief	Relationship added	related to 0000032
2010-04-21 12:14	Footkerchief	Relationship deleted	related to 0000688
2010-04-26 17:42	Footkerchief	Summary	Some world gen mountains halls are inaccessible => Some world gen mountains halls are inaccessible, possibly caused by erosion
2010-12-10 13:16	Footkerchief	Tag Attached: Fixed in 0.31.19?
2011-03-01 14:05	Footkerchief	Note Added: 0015640
2011-03-01 14:05	Footkerchief	Status	new => resolved
2011-03-01 14:05	Footkerchief	Resolution	open => suspended
2011-03-01 14:05	Footkerchief	Assigned To	=> Footkerchief
2012-03-04 08:03	Dwarfu	Tag Detached: Fixed in 0.31.19?