v50 Steam/Premium information for editors
- v50 information can now be added to pages in the main namespace. v0.47 information can still be found in the DF2014 namespace. See here for more details on the new versioning policy.
- Use this page to report any issues related to the migration.
This notice may be cached—the current version can be found here.
Editing Material science
Jump to navigation
Jump to search
Warning: You are not logged in.
Your IP address will be recorded in this page's edit history.
If you are creating a redirect to the current version's page, do not use any namespace. For example: use #REDIRECT [[Cat]], not #REDIRECT [[Main:Cat]] or #REDIRECT [[cv:Cat]]. See DF:Versions for more information.
The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.
Latest revision | Your text | ||
Line 1: | Line 1: | ||
− | + | {{Quality|Exceptional|23:57, 9 October 2013 (UTC)}} | |
− | {{Quality| | ||
{{av}} | {{av}} | ||
{{Material properties}} | {{Material properties}} | ||
− | [[Material|Materials]] have a number of properties representing real-world variables that describe how they respond to inputs. In particular, the game has a number of variables that describe what happens to a material when it's put under stress. | + | [[Material|Materials]] have a number of properties representing real-world variables that describe how they respond to inputs. In particular, the game now has a number of variables that describe what happens to a material when it's put under stress. |
==What is stress?== | ==What is stress?== | ||
Line 11: | Line 10: | ||
In the material raws, whenever you see 'yield', 'fracture', or '[[Strain at yield|strain at yield]]', that property is a stress-related quality. | In the material raws, whenever you see 'yield', 'fracture', or '[[Strain at yield|strain at yield]]', that property is a stress-related quality. | ||
− | ==When does | + | ==When does Dwarf Fortress make stress calculations?== |
At present, DF seems to only apply forces during combat, and thus only stresses objects (generally armor and various body layers) at that time. | At present, DF seems to only apply forces during combat, and thus only stresses objects (generally armor and various body layers) at that time. | ||
Line 22: | Line 21: | ||
===Mechanical Performance Properties=== | ===Mechanical Performance Properties=== | ||
− | Yield: This is almost certainly 'Yield Strength', which is the amount of stress needed to cause a material to go from elastic deformation | + | Yield: This is almost certainly 'Yield Strength', which is the amount of stress needed to cause a material to go from elastic deformation to plastic deformation. (That is, if you cease stressing the object, does it revert to its original shape or not). Since most objects only elastically deform over small distances of deformation, high Yield values generally means it takes a lot of force to noticeably 'stretch' them (but see strain at yield). |
Fracture: The fracture point is the amount of stress or force necessarily to cause the material to fail, or in other words, to break. | Fracture: The fracture point is the amount of stress or force necessarily to cause the material to fail, or in other words, to break. | ||
Line 44: | Line 43: | ||
==Effects on Combat== | ==Effects on Combat== | ||
− | The | + | The Dwarf Fortress combat system does not use all material properties at present (0.40.05). Weapon and armor damage/wear/decay is implemented. |
The formulae below have been reverse-engineered [http://www.bay12forums.com/smf/index.php?topic=131995.0] [http://www.bay12forums.com/smf/index.php?topic=142372.0] and experimentally proven [http://www.bay12forums.com/smf/index.php?topic=116151.0] [http://www.bay12forums.com/smf/index.php?topic=141364] by several independent researchers. Below are the simplified results; for more details see links above. | The formulae below have been reverse-engineered [http://www.bay12forums.com/smf/index.php?topic=131995.0] [http://www.bay12forums.com/smf/index.php?topic=142372.0] and experimentally proven [http://www.bay12forums.com/smf/index.php?topic=116151.0] [http://www.bay12forums.com/smf/index.php?topic=141364] by several independent researchers. Below are the simplified results; for more details see links above. | ||
Line 64: | Line 63: | ||
! Body part | ! Body part | ||
! Relative size (human) | ! Relative size (human) | ||
− | ! | + | ! Kobold |
− | ! | + | ! Elf |
− | ! | + | ! Human |
− | ! | + | ! Troll |
|- | |- | ||
|| Total || 100% || 20000 || 60000 || 70000 || 250000 | || Total || 100% || 20000 || 60000 || 70000 || 250000 | ||
Line 98: | Line 97: | ||
! Size multiplier | ! Size multiplier | ||
! Body part | ! Body part | ||
− | ! | + | ! Dwarf |
− | ! | + | ! Human |
! Extra body parts covered (humanoid) | ! Extra body parts covered (humanoid) | ||
! Notes | ! Notes | ||
Line 127: | Line 126: | ||
===Attack Momentum=== | ===Attack Momentum=== | ||
− | DF uses momentum-based combat physics, so the momentum plays | + | DF uses momentum-based combat physics, so the momentum plays central role in calculations. |
− | Since momentum | + | Since momentum equals velocity times mass, and lighter items can be swung faster, attack momentum is largely independent from weapon weight. The simplified formula is as follows: |
M = Str * Vel / ( 10<sup>6</sup>/Size + 10*F/W ), | M = Str * Vel / ( 10<sup>6</sup>/Size + 10*F/W ), | ||
Line 134: | Line 133: | ||
or | or | ||
− | M = Size * Str * Vel / (10 * | + | M = Size * Str * Vel / (10 * ( 10<sup>5</sup> + i_Size/W )), |
or | or | ||
Line 303: | Line 302: | ||
Items with [STRUCTURAL_ELASTICITY_CHAIN_ALL] or metallic items with [STRUCTURAL_ELASTICITY_CHAIN_METAL] have their [*_STRAIN_AT_YIELD] increased to 50000, which means that blocked attack will not be dampened; it still may be converted to ''blunt'', however. Metal leggings and chainmail shirts have this property in vanilla. | Items with [STRUCTURAL_ELASTICITY_CHAIN_ALL] or metallic items with [STRUCTURAL_ELASTICITY_CHAIN_METAL] have their [*_STRAIN_AT_YIELD] increased to 50000, which means that blocked attack will not be dampened; it still may be converted to ''blunt'', however. Metal leggings and chainmail shirts have this property in vanilla. | ||
− | Items made of cloth with [STRUCTURAL_ELASTICITY_WOVEN_THREAD] additionally have their SHEAR values reduced to negligible 20-30 kPa. | + | Items made of cloth (including adamantine!) with [STRUCTURAL_ELASTICITY_WOVEN_THREAD] additionally have their SHEAR values reduced to negligible 20-30 kPa. This makes candy clothing especially useless in combat. Caps and all clothing have this tag in vanilla. |
===Penetration Depth=== | ===Penetration Depth=== | ||
− | + | This is also very important parameter. | |
+ | Please write something about it. | ||
===Pulping=== | ===Pulping=== | ||
Line 328: | Line 328: | ||
* Chain mail cannot block attacks via momentum cost thresholds; it still can blunt slashing attacks and then deflect them. Thus, the best defence can be reached by wearing ''dense'' (like [[copper]]) mail shirt under a ''rigid'' (like [[candy]]) one. | * Chain mail cannot block attacks via momentum cost thresholds; it still can blunt slashing attacks and then deflect them. Thus, the best defence can be reached by wearing ''dense'' (like [[copper]]) mail shirt under a ''rigid'' (like [[candy]]) one. | ||
* '''Strain at yield''' values are used in comparison to 50000. Since all metals have much less strain values than this, they all can be considered to have ''zero'' elasticity. | * '''Strain at yield''' values are used in comparison to 50000. Since all metals have much less strain values than this, they all can be considered to have ''zero'' elasticity. | ||
+ | * Adamantine clothing is ''absolutely useless'' as armor. | ||
* Armor quality doesn't matter much: masterwork armor provides only about 15% more protection than low-quality one. | * Armor quality doesn't matter much: masterwork armor provides only about 15% more protection than low-quality one. | ||
* Blunt weapon quality appears to not affect damage at all. | * Blunt weapon quality appears to not affect damage at all. | ||
− | With that in mind, here are some numbers for vanilla weapon/armor materials: | + | With that in mind, here are some numbers for vanilla weapon/armor materials: |
{| class="sortable wikitable" | {| class="sortable wikitable" | ||
Line 380: | Line 381: | ||
Clarifications: | Clarifications: | ||
− | On the left side of the table there are some raw values. Density and impact yield are important for a blunt weapon; 4th column is adjusted impact fracture that appears in the formula for blunt defense. Shear fracture is important for edged attacks and defense. Elasticity is in %s of | + | On the left side of the table there are some raw values. Density and impact yield are important for a blunt weapon; 4th column is adjusted impact fracture that appears in the formula for blunt defense. Shear fracture is important for edged attacks and defense. Elasticity is in %s of 50000; as you can see, it is universally low. |
On the right side there are some typical weapon momenta. From left to right: bolt momentum; ditto multiplied by SF and sharpness (signifies piercing ability); short sword momentum in dwarven hands; ditto multiplied by sharpness and SF; dwarf swinging a mace; and minimum momentum '''some''' mace needs to break through armor of '''this''' material. | On the right side there are some typical weapon momenta. From left to right: bolt momentum; ditto multiplied by SF and sharpness (signifies piercing ability); short sword momentum in dwarven hands; ditto multiplied by sharpness and SF; dwarf swinging a mace; and minimum momentum '''some''' mace needs to break through armor of '''this''' material. | ||
{{Category|Materials|*}} | {{Category|Materials|*}} |