The Elusive Stopping Power "Formula" and ArmA 3

[rye1 21]

Scientific proof > opinion. These matters have many misconceptions, it would be best if all comments had references from reputable authors or sites.

@Tom1 On the topic of incapacitation. There is two ways to incapacitate a human target:

A) Hit the central nervous system (fast incapacitation).

B) Loss of blood sufficient to black out the brain or drop blood pressure (relatively slow incapacitation)

Penetration to the vital organs is critical. Given desired penetration, the only way to increase effectiveness if to make the hole bigger or many similar holes. (FirearmsTactical, FBI 10mm Notes, www.firearmstactical.com/pdf/fbi_10mm_notes.pdf)

[-Coulum- 35]

@Rye

Would another way of incapacitating a human be by causing excessive pain (causing them to pass out) as well?

[rye1 21]

Not in that PDF but I'll search some more. :D

[becubed 24]

I am all for body armor As long as it's realistic.

Also, if body armor is implented I really don't want to see people taking a shot or two and not even flinching because they are wearing armor. Wearing armor or not, getting shot is going to Hurt like a bitch and most likly send you into shock, and pain for a fair bit of time. This needs to be implemented in game.

Not really check out some of the video's around the place with people getting shot while wearing vests.

Try this for a guy getting shot with 7.62 NATO, I don't know the date of the video but I would guess that it's around 10 years old. I would guess that in the adrenaline of battle you might not even notice that you were hit.

Vests are also getting better all the time,

is a plate being shot with an M16, it takes 63 hits before a penetration.

[rye1 21]

Well good for a plate taking 63 hits. If the US aren't using it then who cares? Scientific study and proper testing before it's in use anyway so I wouldn't believe manufacturers 'studies'. Not saying it isn't plausable, just saying I'd allow the proper sources to test. And any number of injuries can come from a hit, blunt trauma can cause all kinds of problems.

[-Coulum- 35]

@becubed I think you may have misunderstood me. I don't think that getting shot in the body armor should put you out of action for any more than 5 or so seconds. I just think that there should be immediate and obvious effects, kind of like in this video.

He wasn't down for more than a second but he did go down. I think these kind of hit effects should be in arma.Right now people take shots without armor in arma and don't even flinch if not killed by them.

[becubed 24]

@Rye, of course a manufactures claims shouldn't be taken on face value. The plate they tested could turn out to be another Dragonskin, who knows if it's any good or not. But even if it only stopped 1/10 of the rounds it's still a improvement over performance in the past. I think that in the past armour wasn't really given much of a priority so the R&D wasn't there, now that it has shown it's worth more work is being done on it and I think that more advances will follow.

@Coulum, fair enough and I agree.

[rye1 21]

@Rye

Would another way of incapacitating a human be by causing excessive pain (causing them to pass out) as well?

Weird topic due to it being very psychological and easily influenced by drugs, alcohol, adrenaline and so forth. I can't find anything solid when it relates to wound ballistics. Sure, it's a factor that can cause one to give up the fight but one which has no average and is based on so many variables.

"You don't necessarily faint when under extreme pain; you can though. As far as I know the mechanism behind fainting in such manner is because your heart is essentially thrown into over-drive (fight or flight response), and you faint if you heart can't keep up with the demand of oxygen your body is requiring at such a point. It's not a purposeful evolutionary decision to make the guy pass out to spare him the pain, it's just the result of a cardiovascular system that cannot handle the pressure at that point (and this is obviously dictated by the amount of pain, the diet and overall cardiovascular health of a person, their pain threshold, etc which is why it's not guaranteed you'd faint)." (http://www.zoklet.net/bbs/showthread.php?t=103457)

I would consider that slow incapacitation, wouldn't you?

[crazyjake56 10]

http://www.moddb.com/mods/occupation-source You think Arma 3 should try to do something like this? (It's a source mod.)

[froggyluv 2136]

[ You think Arma 3 should try to do something like this? (It's a source mod.)

Whoa! Thats a pretty serious medical analysis of how you died - especially for CS :D

I like it!

[purepassion 22]

Especially the Trace video is very impressive!

[CarlGustaffa 4]

Nice work on the scopes too, why can't we get partial zooms? :) Yeah, I liked what I saw, even if I'm not into PvP.

[pvt_ryan 10]

Updated with a poll, including the issue of body armor that was ignored in my OP but brought up by others. With regard to the poll, pick which options you think should be simulated (meaning that not all bullets should behave the same way in each of the listed respects), and you can pick as many options as you like, but keep the value of simplicity and technical limitations in mind. Also, thanks for posting all the helpful and interesting resources, everyone.

Edited November 7, 2011 by Pvt_Ryan

[rye1 21]

Also, thanks for posting all the helpful and interesting resources, everyone.

Yeah, the valid ones are the way to go. Good poll. Disagreed on anything mentioning energy though. :p

---------- Post added at 09:42 PM ---------- Previous post was at 09:26 PM ----------

@Rye

Would another way of incapacitating a human be by causing excessive pain (causing them to pass out) as well?

"There is no way to measure or properly assess the role of pain. Many folks not otherwise under the influence of meds/drugs who are shot fall down and cry; others do not have any awareness that they were shot until many minutes later." - Doctor Gary K. Roberts.

[pvt_ryan 10]

Dammit, just realized I forgot barrel length/muzzle velocity in the poll. Well, I'll just assume that since that's already in, in one way or another, everyone wants it, but I'd rather see the velocity be a function of each individual weapon instead of each cartridge.

[dragon01 902]

Everything you listed, plus velocity at the time of impact.

Muzzle velocity doesn't influence damage directly, except at point blank range. Instead, along with drag coefficient and external ballistics in general, it defines how fast the bullet will go when hitting the target.

[pvt_ryan 10]

Everything you listed, plus velocity at the time of impact.

Muzzle velocity doesn't influence damage directly, except at point blank range. Instead, along with drag coefficient and external ballistics in general, it defines how fast the bullet will go when hitting the target.

Of course. I would separate terminal velocity into "muzzle velocity" and "bullet shape/form factor" because some people would rather drag coefficients and their effects (mainly decreasing velocity) be ignored for the sake of simplicity, and they would be able to just choose the "muzzle velocity" option (as opposed to choosing both as you presumably would), but like I said, I forgot to include muzzle velocity anyway. :j: I wish I could edit the poll, but I don't see any way to do so.

[Evil_Echo 11]

All damage effects derive from impact velocity and projectile geometry. Arguments vary on whether momentum or kinectic energy matters more - but both include a velocity component.

The impact velocity is directly tied to muzzle velocity. External ballistics revolve around a round's orientation and velocity. The slow-down is notable, as I mentioned earlier all supersonic rounds eventually drop to sub-sonic speeds - causing disruptions to stablilty as that threshold is crossed.

You may model this to whatever level of detail desired. But unless the model is based on the correct fundamentals, no chance of realistic results can be expected.

[-Coulum- 35]

To me, where the bullet hits is the most important factor when concerning damage. A headshot will do more than a toe shot no arguing about it.

After that though I would have to go with the "big hole" school of thought. larger calibers should induce more pain and bleeding and therefore more damage. and when comparing caliber I think it is important to consider the surface area of the bullet's head rather than the diametre.

Ie often when people compare the 5.56 and 7.62 they say "the 5.56 is about 3/4 the size of the 7.62 so should do 3/4 as much damage". but when it comes to surface area the 5.56 has around half the size of the 7.62 so would do around half the damage. I think that the second method of comparing the two is more accurate.

Fragmentation and tumbling should also be taken into account just as much as the caliber of the bullet. the damage done due to caliber and fragmentation/tumbling would both be effected by the bullet speed upon impact. caliber damage would increase as speed increases and fragmentation would have optimal speeds.

I think one of the most important things about stopping power to represent in game is the fact that people have different pain thresholds/endurances. Therefore it would be good to add a fair bit of randomness to how much damage a target takes to represent the fact that they may be able to shrug off the pain or might make the wound off to be more than it really is. This randomness should make it so no gun ranging from pistol to 50cals should have a guaranteed 1 shot kill unless they hit the head, spine or heart. there should always be a chance even if it is small that the target is able to take the pain and keep fighting.

This kind of system would ensure that different weapons/bullets are stil more/less reliable than one another but none are sure to kill in a certain number of shots, keeping everyone on their toes. Right now I am kind of dissappointed with the lack of variety and randomness concerning damage in A2. for example, the 7.62 scar always achieves one shot kills no matter where you hit. Is there noone in the armaverse capable of pushing through the pain of this shot? apparently not. And I've never seen someone take more than 3 shots to the torso or drop in less than 2 at ranges of 100m - 200m from a 5.56. but in reality2-3 may be the average shots required but some people will be able to take 5 or 6 before they go down while others can take just one in the arm and they give up. Anyways I'm kind of getting lost in my thoughts here. basically I think arma 3 should strive to make certain weapons/bullets have different reliabilities concerning stopping power but make the way damage is handled random enough that anything is still possible even if it is unlikely.

[pathetic_berserker 4]

To me, where the bullet hits is the most important factor when concerning damage. A headshot will do more than a toe shot no arguing about it..

Well arma already does this, with room for imrovement.

Therefore it would be good to add a fair bit of randomness to how much damage a target takes to represent the fact that they may be able to shrug off the pain or might make the wound off to be more than it really is. This randomness should make it so no gun ranging from pistol to 50cals should have a guaranteed 1 shot kill unless they hit the head, spine or heart. there should always be a chance even if it is small that the target is able to take the pain and keep fighting..

Quite like this idea in principle, as there is infact a high number of variables in actual out comes, a system like this could be a good gaming solution to many of the factors listed in the poll. As long as the sense of lethality, a hallmark of the series remains, all would be good and it could beter reflect the reality of those rare reported cases where folks have withstood multiple rounds. I think combined with a random knock down factor that isn't directly conected with damage it could make for some realy ineresting fire fights.

[-Coulum- 35]

Well arma already does this, with room for imrovement.

Yes they do it and yes there is quite a lot of room for improvement. The more the better because it will lead to more variability when it comes to wounding and if more detailed wounding/medic mods are made they will be able to be more complex.

Quite like this idea in principle, as there is infact a high number of variables in actual out comes, a system like this could be a good gaming solution to many of the factors listed in the poll. As long as the sense of lethality, a hallmark of the series remains, all would be good and it could beter reflect the reality of those rare reported cases where folks have withstood multiple rounds. I think combined with a random knock down factor that isn't directly conected with damage it could make for some realy ineresting fire fights.

Better firefights, more immersion and less predictability. don't get me wrong. certain weapons should on average be more likely to kill quicker but nothing will be 100% reliable.

[froggyluv 2136]

Therefore it would be good to add a fair bit of randomness to how much damage a target takes to represent the fact that they may be able to shrug off the pain or might make the wound off to be more than it really is. This randomness should make it so no gun ranging from pistol to 50cals should have a guaranteed 1 shot kill unless they hit the head, spine or heart. there should always be a chance even if it is small that the target is able to take the pain and keep fighting.

Yup, more good stuff here and somewhat of a carryover from the Ragdoll thread. Perhaps the randomness could be modified by skill level and/or class - SF's generally tougher then Crew (in movies anyway) and maybe Meth'ed up Holy Jihadist trumping them all - but still keep random possibility for all. Or better yet, more precise body hitboxes with appropriate consequences :p

[-Coulum- 35]

SF's generally tougher then Crew (in movies anyway) and maybe Meth'ed up Holy Jihadist trumping them all

Yes! That would be awesome. there would actually be a difference between facing a SF guy, conscript, villager fighting to save his family and a guerilla on cocaine.

[rye1 21]

You may model this to whatever level of detail desired. But unless the model is based on the correct fundamentals, no chance of realistic results can be expected.

Exactly why every post should have a reference in these kinds of topics. Personal opinion means nothing.

So to somewhat reference you: "As with most projectiles, the damage pattern in tissue depends on what anatomic structures the projectile hits and at what range/velocity it is hit." - Doctor Gary K. Roberts, in a PM with me and in multiple posts by him on M4carbine.net, just use the search function - I can't be bothered fully referencing it.

---------- Post added at 05:04 PM ---------- Previous post was at 05:01 PM ----------

Well arma already does this, with room for imrovement.

Yeah it only does it when it detects the hit properly, until then expect it to be flimsy half the time.

---------- Post added at 05:05 PM ---------- Previous post was at 05:04 PM ----------

more precise body hitboxes with appropriate consequences :p

Lot's of problems solved... but how hard is that to make? And make up to a good standard... which would mean fast and accurate...

---------- Post added at 05:10 PM ---------- Previous post was at 05:05 PM ----------

50cals should have a guaranteed 1 shot kill unless they hit the head, spine or heart. there should always be a chance even if it is small that the target is able to take the pain and keep fighting.

Some of the cases you here are weird, but uncommon fortunately.

lack of variety

If they model body armour correctly we'll probably see better ammunition for set tasks.

---------- Post added at 05:20 PM ---------- Previous post was at 05:10 PM ----------

All damage effects derive from impact velocity and projectile geometry. Arguments vary on whether momentum or kinectic energy matters more - but both include a velocity component.

Yes, one being sectional density. Sectional density is the bullet's weight distributed over the surface area presented to the medium being penetrated. How it fragments and penetrates. This is important because at different velocities in different areas or angles of attack (AOA) will allow the bullet to act differently. There's always an average, but many many variables and the same exact shot may be slightly different.

(http://www.rathcoombe.net/sci-tech/ballistics/mechanics.html)

I don't believe in the whole story about energy by the way, though I'm not going to diss it. Sure it may cause immediate damage, or slow acting damage over a longer period - but Arma is about the immediate stuff, and stuff that can work quickly in a script. :p

(http://www.rathcoombe.net/sci-tech/ballistics/myths.html)

[dysta 10]

Rye, I've found one of a useful book that is detailize all the bullet ballstic from all the physical factors. I've get quite an idea from it so I may try to put the relation between it and the ARMA bullet damage system together. You may have one if interested. :)