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0008716Dwarf FortressTechnical -- Renderingpublic2015-01-10 03:532015-06-27 14:49
Detros 
 
normalminorhave not tried
newopen 
Linux 32bUbuntu14.04
0.40.23 
 
0008716: Walls with suspended construction get invisible after cave in
During building of yet another wall section I have asked dwarves to channel tiles of 2x2 small cliff. Of course they have managed to dig out those two tiles that connected the cliff first which resulted in a collapse of the rest of cliff. Several dwarves got unconscious for a while, one of them drowned in nearby pool.

The problem is near this small cliff several walls were under construction. Some of these were suspended for a while because there will still some logs obstructing the construction site. After cave in, three or four of these walls became invisible.

I can see them listed with [k], I can assess them with [q] which gives them that green blinking of selected building. Without that, only black tile is showed.
Collapse some area near suspended walls construction sites
Save and world generated in 40.20, save moved to 40.21. No mods.

This seems to be like 0002588 but I am getting "blackness" symbol for those walls.
No tags attached.
related to 0002588acknowledged lethosor Wall tiles after collapse don't match adjacent tiles 
related to 0007496new  Projected constructions look completely black when on a dirty snow 
related to 0009056acknowledged lethosor "invisible" twigs block cave-in 
Issue History
2015-01-10 03:53DetrosNew Issue
2015-01-10 04:17DetrosNote Added: 0031835
2015-01-10 05:09DetrosNote Edited: 0031835bug_revision_view_page.php?bugnote_id=0031835#r12758
2015-01-10 12:42FootkerchiefRelationship addedrelated to 0002588
2015-01-10 17:27DetrosNote Added: 0031867
2015-01-18 03:40DetrosNote Added: 0031981
2015-01-18 03:40DetrosNote Edited: 0031981bug_revision_view_page.php?bugnote_id=0031981#r12814
2015-01-18 04:10DetrosNote Added: 0031982
2015-06-27 14:49lethosorRelationship addedrelated to 0007496
2015-09-02 10:41lethosorRelationship addedparent of 0009056
2015-09-02 10:41lethosorRelationship replacedrelated to 0009056

Notes
(0031835)
Detros   
2015-01-10 04:17   
(edited on: 2015-01-10 05:09)
First level: http://imgur.com/8R6RRqZ,7qJM7Bv#0 [^]
Second level with invisible walls: http://imgur.com/8R6RRqZ,7qJM7Bv#1 [^]
Save: http://dffd.wimbli.com/file.php?id=10409 [^]

It may be connected to 0001205 also though that seems to really changed given tile while here it is rather graphical issue.

Edit: After few game days, some of those invisible suspended-construction walls are now visible. It may have been caused by dwarves collecting those logs in construction area, I guess. Still at least one site is showing "log"/"blackness".

I will go back to uploaded save and try to get the exact moment when those walls get visible again. If they don't show all soon, I will try moving to 40.24.

(0031867)
Detros   
2015-01-10 17:27   
Yes, two tiles appeared after dwarf took away a log from one of them. Another showed itself once the construction was complete. But the fourth and, even a tile next to it (where neither wall nor its construction site was during that cave in) were a bit more weird: they also behaved normally once building was completed and on cancellation of building showed the right tile under them. BUT. Asking for another construction (tried walls, ramps and stairs) on those tiles made building-in-progress show again only blackness.

I guess after all instead of current walls rather some tiles around that collapsed cliff got corrupted in an unusual graphical way.
(0031981)
Detros   
2015-01-18 03:40   
I have got another occurrence a year or two later and in 40.24: one area near my main gate was collapsing every few months (trees around growing? who knows). After lose of the second dwarf to this, I started building roof from walls in that area so, when I am not sure why does cave ins happen, my dwarves will at least by covered.

One of walls got suspended because of log of wood laying on its construction site. That tile was several times hit by cave in dust in last year but seemed to be normal till today. But then construction of that wall got suspended and now it is showing "log" and "darkness" while it should be switching between "log" and "wall". [q] and [k] still do work, as in the previous occurrence.

(0031982)
Detros   
2015-01-18 04:10   
I have tried few more things and probably found it: it is caused by those gray "pile of sand" or "pile of sandy loam" that cave ins leave behind. I have tried all constructions (walls, ramps, stairs, tracks...) and they all behave the same: once you try to build them over a tile with this cave in sand they show as black tiles.

And looking at what walls do when you build them over other types of tiles it seems to me it is clear now what does happen. Unfinished walls are showing their symbol in black and get background according to the tile below them. This background colour can be yellow for sand, white for grass, red for blood pools... or black for cave in sand piles. So that tile which I have considered to show "darkness" or an "invisible wall" in fact (AFAIK) shows "unfinished wall" as black "O" with black background for "pile of sand(y loam)".