The Elusive Stopping Power "Formula" and ArmA 3

[rye1 21]

Awesome! Send it over mate. :)

Thanks a lot.

[dysta 10]

Awesome! Send it over mate. :)

Thanks a lot.

Sen'tya.

[pvt_ryan 10]

Just a quick post, because I don't have the time to write much, but with all these terms being thrown around- ballistics coefficient, drag coefficient, form factor, sectional density, cross-sectional area, and so on- (although of course there's no problem with using more precise language for discussion's sake) we have to remember that all of these quantities are very mathematically related to each other, to such a degree that there would be little advantage to having each one modeled separately in a game like ArmA 3 (with the usual obvious technical disadvantages), so then it becomes a question of which of these measurements is the most versatile. Which does the best job of not only simulating performance over range (through the medium of air) and penetration upon reaching the target (in mediums such as armor or tissue)? What do you guys think?

[dysta 10]

Just a quick post, because I don't have the time to write much, but with all these terms being thrown around- ballistics coefficient, drag coefficient, form factor, sectional density, cross-sectional area, and so on- (although of course there's no problem with using more precise language for discussion's sake) we have to remember that all of these quantities are very mathematically related to each other, to such a degree that there would be little advantage to having each one modeled separately in a game like ArmA 3 (with the usual obvious technical disadvantages), so then it becomes a question of which of these measurements is the most versatile. Which does the best job of not only simulating performance over range (through the medium of air) and penetration upon reaching the target (in mediums such as armor or tissue)? What do you guys think?

Always remember the factor from the energy of all kinds in general. So we don't have to be that complicated to set up what and how the wound ballistic works. Problem is, what kind of computer can fully simulate all the factor of energy seamlessly?

[Cripsis 10]

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.

Wound ballistics is an extraordinarily complex topic, there are so many variables that it's hard to accurately predict wounding potential so in principal I agree with your 'randomness' idea.

[CarlGustaffa 4]

As long as blood splatter isn't shown for every hit you get, because it falsely gives you the impression as you did major damage, I'm pretty much happy with anything. If random factor kicks in when I hit a soldier in the head for only 0.02 damage (could glance his helmet), I don't want that "confirmation" to give me the wrong ideas.

If you combine that with harder to hit (i.e. JCove weapon sway, more easily obtained suppression effects etc), "obvious hits" would be less detectable.

Edited November 9, 2011 by CarlGustaffa

[froggyluv 2136]

Heres the medical screen evaluation after being killed in OccupationCS:

http://i1133.photobucket.com/albums/m594/froggyluv/damage2.jpg

http://i1133.photobucket.com/albums/m594/froggyluv/Damage.jpg

Pretty nice mod here :)

[rye1 21]

As long as blood splatter isn't shown for every hit you get, because it falsely gives you the impression as you did major damage, I'm pretty much happy with anything. If random factor kicks in when I hit a soldier in the head for only 0.02 damage (could glance his helmet), I don't want that "confirmation" to give me the wrong ideas.

If you combine that with harder to hit (i.e. JCove weapon sway, more easily obtained suppression effects etc), "obvious hits" would be less detectable.

This.

Would be nice to see the new animations put to work, because you don't always see blood with a good hit.

Currently the 'ping' looking thing when you hit a helmet and deflect is OK, but thanks to hitdetections it sometimes shows blood (multiple times) and you're like.... so why isn't this person dead?

@froggyluv Very nice.

@Dysta - Awesome book, not one of those wound ballistics books all about "arguements" and pro or against views. It's more of a 'OK, this is the article on that subject, the theories, the equation, the pictures, the case studies, the bigger picture and relationships with other theories" and onto the next. Good referencing, from all kinds of sources too... including Fackler.

[-Coulum- 35]

As long as blood splatter isn't shown for every hit you get, because it falsely gives you the impression as you did major damage, I'm pretty much happy with anything. If random factor kicks in when I hit a soldier in the head for only 0.02 damage (could glance his helmet), I don't want that "confirmation" to give me the wrong ideas.

Yes indeed. This is kind of off topic but when it comes to hit effects, if armor is hit there Should be a different effect than if the helmet is hit or exposed flesh is hit. Would also be nice if blood spatter was a) toned down but made to look a bit more realistic and b) as a shot deals more damage the "intensity" of blood spatter increases. Ie. Shoot someone with an m16 in the arm and you barely get any blood spatter. Shoot someone in the head with a .50 cal. and there is tons of blood spatter. I think it would add to immersion and combined with rag dolls would satisfy my sick craving to shoot poor virtual soldiers.

Edited November 11, 2011 by -Coulum-

[Tom1 10]

I think all of these thigns are great, but I still believe it is possible for realistic wounds to be created using a simplier method.

A complex formula like this is still going to end up operationalising the end result into raw numbers which will end up being the sole damage value.

If we already know how a round works in real life, why bother making a complex formula so that the game can 're-figure' this all out.

Think about it, no matter how complex a formula with bullet mass, bullet calibre, bullet shae and form factor etc is, it will still end up giving a raw number as a damage value.

If each bullet started off with this same number and this number went into a much simplier formula that only worries about bullet velocity and body armour penetration, the affect in game would be the exact same as if we had a massive complex formula.

I aren't the best at explaining things but I will try to explain it better if you guys can't understand.

[pvt_ryan 10]

I think all of these thigns are great, but I still believe it is possible for realistic wounds to be created using a simplier method.

A complex formula like this is still going to end up operationalising the end result into raw numbers which will end up being the sole damage value.

If we already know how a round works in real life, why bother making a complex formula so that the game can 're-figure' this all out.

Think about it, no matter how complex a formula with bullet mass, bullet calibre, bullet shae and form factor etc is, it will still end up giving a raw number as a damage value.

If each bullet started off with this same number and this number went into a much simplier formula that only worries about bullet velocity and body armour penetration, the affect in game would be the exact same as if we had a massive complex formula.

I aren't the best at explaining things but I will try to explain it better if you guys can't understand.

Yeah, I'm not exactly sure what you're getting at. The thing is that we don't perfectly know how rounds behave in real life... but yes, like everything else in a computer program such as a video game, eventually it would be reduced to numbers. I still think more accurate/complex/realistic numbers would be more interesting.

[-Coulum- 35]

I think all of these thigns are great, but I still believe it is possible for realistic wounds to be created using a simplier method.

A complex formula like this is still going to end up operationalising the end result into raw numbers which will end up being the sole damage value.

If we already know how a round works in real life, why bother making a complex formula so that the game can 're-figure' this all out.

Think about it, no matter how complex a formula with bullet mass, bullet calibre, bullet shae and form factor etc is, it will still end up giving a raw number as a damage value.

If each bullet started off with this same number and this number went into a much simplier formula that only worries about bullet velocity and body armour penetration, the affect in game would be the exact same as if we had a massive complex formula.

I aren't the best at explaining things but I will try to explain it better if you guys can't understand.

So basically what you suggest is that each bullet has a base damage it deals which is determined by the devs through research before the game rather than through calculation during the game. In game this base damage will be deducted from/ added to depending on the speed it travels upon impact. And this relation between bullet speed/damage would not be directly proportional. Just because the bullet travels at a higher speed doesn't mean it deals more damage. different bullets will have optimal speeds of impact. So when it comes to in game calculations really all the computer has to do is calculate how close to the bullet's optimal speed it is traveling and what modifier on damage this causes as well as how much damage is multiplied by depending on the placement of the shot.

If this is what you mean I agree, although I feel there needs to be large degree of randomness added to this process to account for the many variables involved in ballistics, and the fact that everyone has different pain thresholds.

Really when it comes down to it, it doesn't really matter how complex the calculations behind the ballistics are. as long as they produce somewhat realistic results it is fine with me.

[dragon01 902]

Actually, let's see:

Bullet mass and caliber: Base Damage, defined for each bullet and slightly randomized.

Penetration and performance vs. armor: Penetration Factor, "flesh" would be threated as a type of armor, when not overpenetrated, full damage would be dealt, if not, it'd be reduced. Low PF, higher chance of dealing full damage, but worse vs. armor.

Terminal ballistics: Overpenetration Damage Multiplier, self-explantory.

Velocity and external ballistics: All of the above would be modified by the impact velocity, all values necessary for an accurate trajectory calculation should be included.

Vital organ damage: I'm proposing a complex medic system which would account for this, see the gore thread for details.

Trajectory and impact velocity would most likely be calculated using a rather equation (which I can't remember right now:)) with a constant drag factor+wind calculation.

So:

Base Velocity: A value defined for each bullet, modified by a "barrel lenght factor" on the weapon.

Fudge Factor: A value defining how much randomness is added into Base Velocity and shot spread. Small for sniper ammo, big for MG ammo.

Drag Factor: How much drag affects bullet trajectory.

Wind Factor: How much wind affects trajectory.

That's 7 values for each ammo type, which sound reasonable to me.

I'd add two more things to define:

Caliber: Caliber name, any weapon designed to chamber that caliber or a mag/belt designed to be used with it could be loaded with the ammo in question (better than the current system).

Powder Load: A value which would differentiate, for example, "magnum" loads from normal. Compared with weapon's "Tolerance" value, if too high, boom Just like in real life, the fact you can chamber an overpowered cartridge into a gun doesn't mean you should.

I think that this would make a rather realistic model without too much complex calculations. You've got 7 basic values that affect ballistic performance, all clearly defined and quite flexible. The last two are here because I'd like to see an improved ammo management system in AIII. You could, in a pinch, pry a few rounds from an M2 MG belt and put them into your M107 (if you've kept empty mags, you can put them into one, otherwise, straight to the chamber), but you'd have poor accuracy when shooting MG quality ammo.

[pvt_ryan 10]

Actually, let's see:

Bullet mass and caliber: Base Damage, defined for each bullet and slightly randomized.

Penetration and performance vs. armor: Penetration Factor, "flesh" would be threated as a type of armor, when not overpenetrated, full damage would be dealt, if not, it'd be reduced. Low PF, higher chance of dealing full damage, but worse vs. armor.

Terminal ballistics: Overpenetration Damage Multiplier, self-explantory.

Velocity and external ballistics: All of the above would be modified by the impact velocity, all values necessary for an accurate trajectory calculation should be included.

Vital organ damage: I'm proposing a complex medic system which would account for this, see the gore thread for details.

Trajectory and impact velocity would most likely be calculated using a rather equation (which I can't remember right now:)) with a constant drag factor+wind calculation.

So:

Base Velocity: A value defined for each bullet, modified by a "barrel lenght factor" on the weapon.

Fudge Factor: A value defining how much randomness is added into Base Velocity and shot spread. Small for sniper ammo, big for MG ammo.

Drag Factor: How much drag affects bullet trajectory.

Wind Factor: How much wind affects trajectory.

That's 7 values for each ammo type, which sound reasonable to me.

I'd add two more things to define:

Caliber: Caliber name, any weapon designed to chamber that caliber or a mag/belt designed to be used with it could be loaded with the ammo in question (better than the current system).

Powder Load: A value which would differentiate, for example, "magnum" loads from normal. Compared with weapon's "Tolerance" value, if too high, boom Just like in real life, the fact you can chamber an overpowered cartridge into a gun doesn't mean you should.

I think that this would make a rather realistic model without too much complex calculations. You've got 7 basic values that affect ballistic performance, all clearly defined and quite flexible. The last two are here because I'd like to see an improved ammo management system in AIII. You could, in a pinch, pry a few rounds from an M2 MG belt and put them into your M107 (if you've kept empty mags, you can put them into one, otherwise, straight to the chamber), but you'd have poor accuracy when shooting MG quality ammo.

Couldn't have put it any better myself. I'm not sure how you would go about getting measurements with regard to "wind factor", though. Bullets with high velocities and aerodynamic shapes such as sniper boat tail rounds would naturally be affected by the wind less in such a way that what compensation is needed may already be accounted for, as there is less time for faster bullets to be pushed off course by the wind.

[dragon01 902]

They could always get a sniper and ask him if they got the factor right. :) It'd be a generic "how much a bullet is affected by the wind" value, so mass, velocity, size and shape would all matter. .50 BMG would have it lower than 5.56 NATO, for instance.

[LeMask 1]

Well, you know, video games suffer from one thing... Lack of talent.

I can give you tons of money and you will be able to buy skills on the market... But talent needs time and more talent in the management/leadership.

Arma is a perfect exemple of that. Good potential... But it misses the target for some reason.

You have two simple choices if you want to do things right.

Simulation or illusion

If you want to have a good damage management in your game... You do a real simulation, where the computer execute tons of math based processes to check the damage.

Or you can make an illusion of realism...

My call would be to use both and get both half way... Take the best of both techniques.

Rather than to add tons of hitboxes for the simulation of a a torso with a heart etc etc...

I would make categories of "shots". With two factors. Penetration/damage (high penetration/high damage for a 50 cal as an example, and a high damage/low penetration for a 9mm.

And let a 7.62mm from a Sniper rifle be a medium damage/high penetration at close&medium range and high damage/medium penetration at long range...

It's better than a math based simulation of ballistics. (the bullet transfers more energy to its target at long range as there is a loss of speed)

And about damage, I prefer percentiles with an event system like RPGs (role playing games.

Hit from the front in the upper torso

Unarmored target

Average damage bullet

High penetration damage

=

10% fatal heart wound

15% damaged artery + severe bleeding

50% punctured lung

30% destroyed shoulder

etc etc...

And if the bullet is low penetration, the chances of a severe wound should be higher

And if the target is well armored. The bullet doesnt penetrate, but knocks the guy down and break some bones making the breathing hard.

And if it's not that well armored (no trauma plate). The armor absorbs the some energy and fails with a catastrophic penetration... Following the quality of the armor.

Real real events with huge grids of possible outcomes rather than Simulation.

[-Coulum- 35]

And about damage, I prefer percentiles with an event system like RPGs (role playing games.

Hit from the front in the upper torso

Unarmored target

Average damage bullet

High penetration damage

=

10% fatal heart wound

15% damaged artery + severe bleeding

50% punctured lung

30% destroyed shoulder

etc etc...

I kind of like this idea. Would add randomness to wounds so they are never the same twice, would allow for a more complex medical system, and probably isn't as system intensive as making tons of individual hitboxes. could be pretty interesting.

[Gnalvl 1]

I think wound profiles of various ammo types need to be considered rather than simply leaving it up to only muzzle energy, penetration, or "energy transfer" calculations. If you're going to ignore the fact that 5.56 FMJ fragments [sometimes!], 5.45 FMJ yaws early, and both 7.62 caliber's FMJ merely go in and out in most instances, then when it comes to terminal ballistics Arma 3 would be no better than COD, CS, BF, or any other military-themed arcade shooter. What's more, when it comes to JHP, JSP, OTM, AP etc rounds, the ball game changes completely, and you can't really come up with one model to summarize the performance of all bullets available in a single caliber, particularly when rounds that perform the worst in FMJ suddenly perform the best when the right ammo is used.

As others have stated, it's probably too much to expect real-time calculation of bullets penetrating, yawing, fragmenting, expanding, etc through organs, tissue, and bone. However, even if each round were to be assigned a simple numeric value based on an average of its penetration, temporary cavity, permanent cavity, etc. which was factored in with velocity and shot placement, then that would take the damage model light years ahead of arcadey alternatives.

[Tom1 10]

mass x coefficient / velocity + calibre = unnecesary calculations.

All of that will eventually turn into one number which is the damage value yes?

Figure all that stuff out outside of the game then operationalise the result (which is what's going to happen if the big calculation is ingame as well) into a single number, then put that into an ingame formula that uses only the velocity of the projectile, the section of the body it hit, the SINGLE [predetermained] damage value, and if the engine can handle it also add in angle of impact.

Why have 100 different variables all being checked in an ingame formula for each time one bullet hits someone just to determain a single value [the damage value], when you could just do all of that outside of the game and keep the predetermained damage value and put into a much more simple damage formula with only really relevent variables like velocity of the bullet (because at different ranges bullets will have different effects).

You could give an M855A1 a higher than average base value and chuck it into a formula that measures its velocity. The M855A1 (5.56x45mm NATO ball round) will have a high end result if travelling over 600m/s because we already know from real life data and from our formula that has already been used OUTSIDE of the game that the M855A1 round fragments exceptionally well within 300 metres, or at speeds greater than 600m/s.

That damage value could be used to determain how much a unit is bleeding (no instant kills after enough damage adds up, units only die from headshots, explosions, collisions and bleeding out, and damage to the arms should not add to an overall damage value).

Seriously guys, I'm not here trying to be that annoying troll trying to destroy your idea, I'm here to give suggestions as to how the game could get better, without slowing down and lagging out the games of those people living in countries with slow internet (In Aus sometimes it takes a good 10-20 shots [all hits] to a taliban before it realises it's been shot and actually takes damage, complex formulas for each bullet will slow the game down even more) my solution is very simple: Go ahead with plan but don't use the formula ingame, instead determain the damage of a round outside of the game with THE SAME FORMULA, because this will lead to less lag.

And I know how you all feel about making the game extremely realistic, I had a few threads set up aiming to convince BIS to put in sucking chest wounds, cardiac arrest, spinal injuries, internal bleeding, stomach ruptures, shock, clamping arteries etc but the thing is, the game is aimed to simulate military combat, not simulate every type of wound on the planet. Two or more sides battle it out in realistic scenarios with realistic equipment and tactics, if someone gets shot he will be wounded or killed, and players and AI use realistic tactics to react to the casualty.

If someone gets shot they need to be stabilised which will slow down the team with the casualty because another team member has to slow down the fighting to help his friend. That is realistic. If the person is shot to the body and is instantly killed because of Arma 2's dated damage formula, it is not realistic.

With super realistic sucking chest wounds and medical equipment and procedures will the game be more realistic? Not by much, the casualty is still being treated by a medic and is still wounded and slowing down his team, but after all the super realistic treatment he just stands right back up and fights. = Unrealistic.

The aim of realistic wounds is to make the flow of combat more realistic in the sense everyone has to know how to react to an enemy when they have casualties. It will add a whole new aspect of tactics in a firefight. But what is the point of super realistic wounds and treatment compared to simple bleeding and incapacitation and bandages and medkits when the process is still the same, the man is healed and eventually stands up, and the only major difference is that the game will lag 100 times more with the more complex stuff (in multiplayer anyway).

I know the post was exceptionally wrong, but please understand there is no point over complicating things when it will all work the same ingame. You can simulate realism by being more simple rather than making the game heaps slower only to achieve the same end result. I am not sticking up for the current system, I like your ideas, but they need to be simplified.

[rye1 21]

"Physics. It's real. Kinetic energy is simply a measure of the work potential of a projectile. As noted above, although part of the equation, kinetic energy in and of itself it is not a predictor of incapacitation effectiveness. Recall:

-- Bullets cannot physically knock down a person by the force of their impact.

-- Kinetic energy or momentum transfer from a projectile to tissue is not a wounding mechanism.

-- The amount of "energy" deposited or momentum transferred to a body by a projectile is not directly proportional to the amount of tissue damage and is not a measure of wounding power.

-- Wounds of vastly differing severity can be inflicted by bullets with identical kinetic energy and momentum.

What a bullet does inside the body--whether it yaws, deforms, or fragments, how deeply it penetrates, and what tissue it passes through is what determines wound severity, not KE!" - Doctor Gary K. Roberts, FBI Wound Ballistic Expert. Energy transfer in relation to wounding is not a fact, a science or a confirmation; it is a theory.

[Serclaes 0]

It's a little confusing.

-- Bullets cannot physically knock down a person by the force of their impact.

This goes against everything I know. German police started using softpoint rounds because they have greater stopping power. I know hunters in germany use softpoint rounds because of the stopping power.

Consider this: the energy of a round is 1/2*mass*speed². The important factor of stopping power is how much energy is delivered to the body in the fewest distance possible. The more friction, the more energy is delivered. But then again it depends of course on the weight of the target (inertia and such).

Or maybe I don't understand what he means by "impact"...

[rye1 21]

Knock a person down... physically knock them down. As in a bullet hit someone and they go flying 20 feet :D or get knocked down like a hit off Mike Tyson.

Not to cause enough pain to debilitate, or to wound a muscle, tissue type or fragment bone enough to bring someone to the floor.

The important factor of wounding, not 'stopping power', it is what anatomical structure is hit and how much damage is done to that area, i.e. permanent cavity, tissue and organs affected. Maybe re-read it a few times to understand it.

[Serclaes 0]

The article makes sense. Just that one point doesn't. Wounding is of course related the area hit. Tho larger rounds with great ke would help with making more "damage" ;)

I saw boars and red deers go down on impact. I really don't get his point.

[Dead3yez 0]

Performance vs Armour is big for me. Armour including light vehicles and air targets.

Bigger weapons like the .50 M2 should be able to penetrate aircraft and kill the crew / passengers inside.

[rye1 21]

It's simply saying KE is not a fact. It's a theory, and one that has been negated by many Wound Ballistic Experts, Researchers and Scientists. The boars didn't go down because simply energy was transfered into their body. KE tells us nothing on tissue damage, and nothing on wounding capacities or physical trauma. It is a very poor proxy for depicting bullet performance.

Larger rounds is a bigger construction of the projectile, larger mass. You're going to create a larger wound tract. Nothing to do with energy.