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IDProjectCategoryView StatusDate SubmittedLast Update
0002813Dwarf FortressDwarf Mode -- Combatpublic2010-07-24 13:342011-03-23 13:16
ReporterCephas 
Assigned ToToady One 
PrioritynormalSeveritymajorReproducibilityalways
StatusresolvedResolutionduplicate 
PlatformOSOS Version
Product Version0.31.11 
Target VersionFixed in Version0.31.22 
Summary0002813: Glass weapons (in traps) are comically ineffective
DescriptionMasterwork Glass weapons in weapon traps made with exceptional mechanisms will deflect off of the lowest grade armors in existence, namely no-quality cloth / leather / silk. Goblins encountering these traps will walk through 4-10 10x Serrated disks before passing out while still not receiving any injuries. They eventually wake up and trek back out.

I assume this draws from the combat changes with all the other materials. Sadly, there's no way to compare values for glass as it isn't in the raws.
Steps To Reproduce
Additional Information
Tagsglass
Relationships
child of 0003071resolved Toady One All hardcoded materials (glass etc) have uninitialized MAX_EDGE and ABSORPTION and crappy yield/fracture/strain values 
Attached Files
Issue History
Date ModifiedUsernameFieldChange
2010-07-24 13:34CephasNew Issue
2010-07-24 21:05CephasIssue Monitored: Cephas
2010-07-25 19:24CephasNote Added: 0011046
2010-07-25 19:24CephasNote Edited: 0011046bug_revision_view_page.php?bugnote_id=0011046#r4305
2010-07-27 06:59RaskNote Added: 0011155
2010-07-27 07:09FootkerchiefNote Added: 0011157
2010-07-27 08:15smjjamesNote Added: 0011158
2010-07-27 08:19smjjamesTag Attached: glass
2010-07-27 11:04QuietustNote Added: 0011163
2010-07-27 11:30QuietustNote Edited: 0011163bug_revision_view_page.php?bugnote_id=0011163#r4350
2010-07-27 11:57QuietustNote Edited: 0011163bug_revision_view_page.php?bugnote_id=0011163#r4351
2010-07-27 11:57QuietustNote Edited: 0011163bug_revision_view_page.php?bugnote_id=0011163#r4352
2010-07-27 12:55hyndisNote Added: 0011166
2010-08-19 12:46QuietustNote Added: 0011928
2010-08-19 13:08QuietustNote Edited: 0011928bug_revision_view_page.php?bugnote_id=0011928#r4637
2010-08-19 17:10CrytenNote Added: 0011937
2010-08-19 17:52Logical2uRelationship addedrelated to 0003071
2010-08-19 18:07ShurhaianNote Added: 0011941
2010-08-19 18:14ShurhaianNote Edited: 0011941bug_revision_view_page.php?bugnote_id=0011941#r4641
2010-08-19 18:29ShurhaianNote Edited: 0011941bug_revision_view_page.php?bugnote_id=0011941#r4644
2010-08-20 03:26deathc4Note Added: 0011953
2010-08-24 07:17CephasNote Added: 0012058
2010-08-27 09:16BeeskeeIssue Monitored: Beeskee
2010-08-27 13:47knofbathNote Added: 0012174
2010-08-27 14:07knofbathNote Edited: 0012174bug_revision_view_page.php?bugnote_id=0012174#r4732
2010-08-28 06:34Knight OtuNote Added: 0012191
2010-08-28 21:52knofbathNote Edited: 0012174bug_revision_view_page.php?bugnote_id=0012174#r4748
2010-10-01 14:21NidorNote Added: 0013101
2010-10-26 01:19lolghurtNote Added: 0013516
2010-11-05 08:27CephasNote Added: 0013628
2011-03-02 09:38FootkerchiefRelationship replacedchild of 0003071
2011-03-09 04:05Toady OneStatusnew => resolved
2011-03-09 04:05Toady OneFixed in Version => 0.31.22
2011-03-09 04:05Toady OneResolutionopen => fixed
2011-03-09 04:05Toady OneAssigned To => Toady One
2011-03-23 13:16FootkerchiefResolutionfixed => duplicate

Notes
(0011046)
Cephas   
2010-07-25 19:24   
I just had a bronze Colossus run through 110+ Exceptional 10x Glass Serrated disk traps without a scratch. While it is understandable that it might not die, the fact that material differences result in complete deflection as opposed to conversion to blunt damage feels like a bug to me.
(0011155)
Rask   
2010-07-27 06:59   
Maybe they are too light to do damage? Green glass balls have a weight of 2, which is twice that of a goblet.
(0011157)
Footkerchief   
2010-07-27 07:09   
Huh. I wonder if the density of glass never got updated for the new weight system.
(0011158)
smjjames   
2010-07-27 08:15   
Maybe its time for Toady to put glass up in the raws? AFAIK, they aren't.
(0011163)
Quietust   
2010-07-27 11:04   
(edited on: 2010-07-27 11:57)
Even a spiked iron ball weighs only 7kg, which works out to about a 10cm diameter sphere plus the spikes (if it was a smooth sphere, it'd be 12cm diameter), which is a pretty reasonable size.

An iron statue weighs 471kg while a glass statue weighs 156kg, which puts glass's density at a perfectly acceptable 2.6g/cm^3.

The fact that a spiked glass ball weighs only twice that of a goblet means that goblets are way too heavy.
(0011166)
hyndis   
2010-07-27 12:55   
Glass in the raws would do it. Probably for balancing purposes make glass be roughly as effective as copper. Glass can have much more of an edge than wood, but not as much of an effective edge as metal due to how fragile glass is. Also glass is heavy. Even if the glass object has no edge or point on it at all the sheer mass of the glass object should cause some hurting.
(0011928)
Quietust   
2010-08-19 12:46   
(edited on: 2010-08-19 13:08)
Some digging through the game's memory suggests that glass's YIELD and FRACTURE values are only 10000 (making it about as strong as wood) and the STRAIN_AT_YIELD values are all 0 (making it extremely brittle), which may explain why it's so weak. 0003071 also reveals that glass's MAX_EDGE is undefined (i.e. it's random each time you play), though it's not clear what effect MAX_EDGE has during combat.

For those curious, all 3 types of glass have a SOLID_DENSITY of 2600, making it about as dense as any layer stone other than rock salt.
(0011937)
Cryten   
2010-08-19 17:10   
I don't know if its relavent but it seems logical to me that a massive creature made of metal could easily walk over traps full of glass spikes and disks unharmed. I would imagine the creatures copper skin would be something like an quarter of a metre thick making any glass weapon not just one massive giant pile driver scratching even copper given its brittleness *kashatter*.
(0011941)
Shurhaian   
2010-08-19 18:07   
(edited on: 2010-08-19 18:29)
The thing is that glass is actually VERY HARD. Harder than most metals, and capable of holding a wicked edge - scored and cracked glass is pretty close to a monofilament edge, and is used for slicing sections for viewing in a tunneling electron microscope. To cut glass, you need gemstone(emerald, corundum, or preferably diamond) tools. Hardened steel may work, but I'm not sure the methods available to dwarves could produce that sort of hardening - some degree of quenching and tempering is required, and I can't readily find a reference as to how finely it must be controlled. Either way, at Mohs 6-7, it's harder than annealed steel, or bronze, or whatever else.

We think of glass as weak because it's brittle when extruded in thin sections. A solid mass of glass is actually quite tough - and even if it chips, that just means that you've now exposed a brand new edge. Sharp glass might lose its edge when it hits something like a bronze colossus(or rather, would be left with less projecting "edges", most likely, in the case of a spiked ball), and armor might blunt its effect, but anything relying on solely its surface for protection shouldn't walk away without a scratch. A hit by glass with only yielding material in the way(cloth) should be felt.
(0011953)
deathc4   
2010-08-20 03:26   
From a sadomasochist's point of view I really like the glass traps the way they are. Goblin runs in, gets about 100 minor wounds, and then takes a slow painful year to die.

That's why you build iron traps beyond the glass ones. The strong get a quick death while the weak suffer.
(0012058)
Cephas   
2010-08-24 07:17   
@deathc4 - Problem is, it doesn't work like that. Goblin runs in, gets about 0 wounds at all due to constant deflection, eventually passes out from exertion due to his or her own attempts at dodging and then wakes up a little later to walk right back out.
(0012174)
knofbath   
2010-08-27 13:47   
(edited on: 2010-08-28 21:52)
Trap components all do blunt damage, not edged. The issue here is that blunt weapons are currently ineffective.

[edit]
whoops, nvm, I don't know what I was thinking when I wrote that, must have been too short on sleep, gotta check my facts more

I've been exploiting the lethality of whips in my current traps, that'll probably be fixed whenever the next version hits though
(0012191)
Knight Otu   
2010-08-28 06:34   
What makes you think that trap components do blunt damage when they all have the edge tag?
(0013101)
Nidor   
2010-10-01 14:21   
Though it has been around a month since the last post. Had masterwork glass discs with masterwork mechanisms vs an elf merchant that fell unconscious on one. result was 30x deflected by no quality rope reed fiber cloak. So it looks like glass traps are still busted. Shame, was hoping to make the entire fort out of green glass (sans barrels and beds of course).
(0013516)
lolghurt   
2010-10-26 01:19   
interestingly, glass spikes seem to be at least capable of passing through normal clothes.
(0013628)
Cephas   
2010-11-05 08:27   
@lolghurt

Out of curiosity, were these dwarves that you attempted to impale, were the spikes in retractable spike traps, and could you provide some combat logs?