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[Aedom]

Oh great and knowledgeable bay12forum users,

In the raws, there is a relative thickness defined for each tissue layer.  That relative thickness is used to calculate a physical thickness for the layer testing, depending on the creature size.  That calculation is simple, but so far I have not had any success figuring how tissue layer thickness affects the weapon momentum as the strike passes through armor/tissue layers. 

I have been going over the wiki and any materials I can find on the web, specifically these pages:

http://dwarffortresswiki.org/index.php/40d:Wound
http://dwarffortresswiki.org/index.php/40d:Weapon
http://dwarffortresswiki.org/index.php/40d:Combat
http://dwarffortresswiki.org/index.php/DF2014:Material_science

It seems that there are only two possible outcomes at each layer:

1) The attack is completely absorbed and no damage gets through (edged elastic case)
2) The attack breaks through the layer, by exceeding the momentum check threshold.  Momentum is taxed 5% before proceeding to the next level.

Neither of these documented outcomes seems to scale the momentum tax with regard to how thick the layer is.

I'm sure I have over simplified things, but can anyone shed any light how or whether the tissue thickness feeds back to affect the strike momentum?  It seems to me that
the thickness of the layer should affect how much momentum is lost.  Is my intuition wrong here?  If so, then what is the tissue thickness ultimately even used for?



Thanks for reading

[Grimlocke]

Tissue thickness is simple a weighted value for how much of the bodypart of made up of that tissue, as you said.

Much more of the combat mechanics will be determined by the tissue material, and what kind of tissue you are using (STRANDS and FEATHER tissues are ignored for most of combat calculations).

Combat in general can be pretty flaky and balancing an armor-like tissue layer right can be kind of a trial and error process. You can make a tissue or armor material that will absorb a portion of impact damage with these kinds of properties:
   [IMPACT_YIELD:100000]
   [IMPACT_FRACTURE:100000000]
   [IMPACT_STRAIN_AT_YIELD:30000]
These scale fairly will with both tissue layer thickness and armor thickness (I use this for padded armor in my mod).
   [IMPACT_YIELD:1505000]
   [IMPACT_FRACTURE:2520000]
   [IMPACT_STRAIN_AT_YIELD:32500]
And this one I use for lower-quality steel, it will negate blunt force entirely for weaker attacks, and still negate a portion of the damage for stronger attacks.

Edged damage is a bit finicky, and rather unrealistic for the most part. Materials with significantly higher shear values will carve through lower-shear resistance materials with little to no momentum cost. For instance, a steel sword will chew through a thick chunk of copper will fairly little effort at all, which is kind of bollocks.

A way around this is to make a very thin layer with shear values close to the materials its expected to by hit by. Similar materials don't seem to suffer from the lighsaber weirdness. It will convert low impact, edged attacks to blunt damage and will still impede stronger edged attacks.

I made an armor man creature which uses a similar approach, the material I used is similar to steel and the tissue layer is around 3:375 to 8:300 thick proportionally, on a human sized creature. Making it thicker than that quickly turns it into a invincible tank-man.

Edit: Here's a rather helpful thread with some of the actual maths behind it all explained: http://www.bay12forums.com/smf/index.php?topic=131995.0 its a tad dated, but combat and material fundamentals haven't changed much since.

[Putnam]

http://dwarffortresswiki.org/index.php/40d:Wound
http://dwarffortresswiki.org/index.php/40d:Weapon
http://dwarffortresswiki.org/index.php/40d:Combat

Check the top of the page--these are for DF version 0.28, before the complete material, combat and body overhaul done in 0.31. The information will not be useful at all.