View Full Version : bullet penetration and damage numbers...

31st Jan 2002, 03:15 PM
Excuse me if this is a revisit of a past topic....

I had a question about bullets that penetrate objects (like boxes, walls, other players) and the damage inflicted by them should they hit someone.

Example scenario: I have full health. I am fully hidden behind a sandbag/thin concrete wall. Someone fires a robar at the wall, striking my approximate location.

Question- assuming that the bullet can and will penetrate that barrier, will I have the full amount of damage from a robar round subtracted from my health (IE: dead)? Is there a 'penalty' for rounds that travel through another object before striking a player?

I'm a bit ignorant of the penetration values of rounds/weapons, and which objects can and cannot be penetrated by weapons fire, so forgive me in advance :).

If there is no current system in 2.86, should there be one for 2.87? I'd imagine that something similar would have to be implemented in 2.87 for the body armor to be effective, but I was wondering if it would be extended to other objects as well.

31st Jan 2002, 03:40 PM
I don't have an answer for you - but I would like to know this as well. I guess it all depends on how much thought was given to the realism effect in INF. It would only make sense a .50 cal bullet would tear through a sandbag, but it would certainly not result in full damage because the speed of the bullet has been drastically reduced (i.e., less blow-out). I'm not sure if any of this is even considered in INF (Does the bullet just get an object collision and stop there - like it would in a wall?), but would be a great idea for a future release if not...


P.S. - Maybe you should post this in the 'New Version Suggestions' forum also...

31st Jan 2002, 03:44 PM
uhh seeing that the robar hits for like 689 damage it doesn't matter, but no it doesn't lessen the damage

31st Jan 2002, 03:47 PM
hah, well, the robar was just an example. It was really a question about all weapons, their ammo, and stopping power. As I said, I'm not sure which weapons are actually able to penetrate objects, and which objects are penetrable.

31st Jan 2002, 03:58 PM
It doesn't lessen the damage? Well, I'm no ballistics expert but that doesn't seam realistic to me (maybe this is a short comming of the current version of INF). If the majority of the bullet's kinetic energy is lost in the penetration, then I would expect the wounding ability of that projectile to be significantly lessened.

31st Jan 2002, 04:03 PM
Originally posted by rgreene
It doesn't lessen the damage? Well, I'm no ballistics expert but that doesn't seam realistic to me (maybe this is a short comming of the current version of INF). If the majority of the bullet's kinetic energy is lost in the penetration, then I would expect the wounding ability of that projectile to be significantly lessened.

Exactly. I think we all agree on that, but the question is wether the current version, 2.87, or a future release will even consider this fact.



31st Jan 2002, 04:21 PM
eh.... if a bullet penetrates you ANYWHERE no matter how slow it was going... its still airborn and it will penetrate and render you uselss

dont think of it as "damage" or "life"

sure a soldier could fight a little longer if he leg is shot maybe... but he wont do anywhere... nor will he be able to aim as accuratly do to the loss of concentration to pain

if it exits the object it went through... and you dont have a vest on ... then youll die no matter how slow if its still airborn

31st Jan 2002, 04:36 PM
Originally posted by bastardb
.... sure a soldier could fight a little longer if he leg is shot maybe... but he wont do anywhere... nor will he be able to aim as accuratly do to the loss of concentration to pain.

Maybe this could be another "realism" factor to implement. Impaired aim and movement when wounded...

Originally posted by bastardb
...if it exits the object it went through... and you dont have a vest on ... then youll die no matter how slow if its still airborn

I certainly don't agree with that statement however. I'm no ballistics expert either, but it depends where on your body the bullet strikes! A full force bullet to your foot isn't going to kill you just as a slowed bullet to a limb or possibly torso might not either.

How can you say as long as it is airborn you will die?? If a bullet strikes my chest full force I have a giant hole in the front and half my back is blown out. But if it comes through a pile of sandbags or a thick wooden door it might only barely penetrate or lodge internally. Even this scenario is potentially fatal, but your chances of survival are much greater - not just *BOOM*, you're dead like in the first scenario.

Anyway, that's my $0.02


31st Jan 2002, 04:37 PM
Originally posted by bastardb
if it exits the object it went through... and you dont have a vest on ... then youll die no matter how slow if its still airborn
That depends on the speed/energy it has left after exiting the objekt.

/ `-
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: ; / /+ | / ;`-,
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.' \ .' | \ : | \
/ / | \ | ;
/ / : \ ;
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Bullet | ;
| ;
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Object still airborne but
f00kin harmless
exept it hits
your eye

spelling and... instaposted

31st Jan 2002, 04:49 PM
Just to be a troll:
I bet if I threw a bullet at you, and hit you, you wouldn't die. Yet, it's airborn...

31st Jan 2002, 05:29 PM
Nice drawing Hadmar....lol...gets the point across though

31st Jan 2002, 05:32 PM
Im quite familiar with inf's system, Ive studied it and modified some of it with RA.

Yes, bullets can penetrate objects. I can get you a list of comparative penetration values, but I gotta scrape it all together. It penetrates through objects based opon thier thickness, and does pay no attention to the "material".

No, bullets do not do less damage after going through an object.
But, a slower shot doesn't nessesarily mean it should hurt less - in some cases, its the opposite. This is ridculously simplified, but imagine a bullet going through a person cleanly, then another bullet that just hit(and passed through) another object. It could be wobbling and 'turning' now, and possibly even be fragmented, and expanded due to heat. A clean hole, that is not, and it may possibly be a more fatal wound...
Of course, something like that would be more likely to be stopped by body armor (In real life), but thats quite a sophisticated subject.

31st Jan 2002, 05:41 PM
What yurch said :D
But i know from experience that bullets in inf can still kill after traveling through objects. Once on Manorfarm i riddled a door full of bullets and lo and behold on the otherside lay a pile of dead bodies. Coincidence? I think not :)

Kuroshio Apocal
31st Jan 2002, 05:54 PM
Where's Tiffy? His word on wound ballistics would be greatly appreciated.
As for faster bullets hurting more, I've always looked at it as the difference between someone using a sharp axe to take off your head compared to a dull one.

31st Jan 2002, 06:08 PM
ok by "die" i meant being rendered useless to battle... thus being removed by a medic etc

if more then 3/4 of the bullet enters your body, im pretty sure youd be classified out of action

since if it had enough force to penetrate whatever your clothing.. and whatever then it will penetrate your skin causing a yankload of pain... you would not be staying in the fight

that picture you drawn is almost impossible...
i understand what you meant... it will not have the same velocity exiting as it did entering yes... but if it doesnt stop inside then its about 1 in a million chance it will come out with low enough velocity to just arch out at such a sudden drop like that

the game only needs to make the alteration of bullets being effected nt only by thickness... but my substance... there should be no "loss of amount of damage"
also maybe an altered trajectory slightly from the exit.. possibly more downward...
but no less damage still (unless of course it happens to hit there leg rather then there body which i think inf distinguishes right?)

the game already simluates it well enough mostly by thickness... if its too thick it doesnt go through at all... which in some cases it would but be slowed down alot
or if its relatively thin... then it should go through with minimul velocity loss

31st Jan 2002, 08:09 PM
In INF if a bullet penetrates cover it is as if there was nothing there at all, so the damage done to you is the same. Yurch is the expert on this side of things really.

In real life lots of things happen. The speed of the bullet has nothing to do with the damage it will do to you, it mearly makes it easier to hit you due to the flatter trajectory the bullet flies from the muzzle to you.

The amount of damage that you take, the wound severity, is dependant on how much energy the bullet can transfer to you. Most modern military rounds are acctually very bad at transferring energy and will over-penetrate the target (thats you) only passing some of its energy to you.

How much this effects you is really dependant on several factors. Where it hits you, a head wound is more likely to incapacitate you than being shot in the foot or hand. (But you can, and people have, died from being shot in the foot.) It also depends on how 'hyped up' you are on adrenaline. People have been shot several times and kept going, or not even realised it, whilst others have been rendered incapacitate form a small scratch.

When firearms are designed the excepted amount of energy transfer that will incapacitate someone is 80J. There is approximately 15% of your body that when hit will always result in an incapacitating wound from this energy transfer (head and upper neck). There is a 30% area that will probably result in an incapacitating wound (I can't remember the % chance. This is the upper central torso and chest), and finally the rest of the body, 55% (arms, legs, edge of torso and other bits and pieces) that has about a 50% chance of incapacitating.

Weapons designed for the British Army have to have a 99% chance of incapacitating a person at 100m within 1 second. This means they have to be designed so that they can hit the head at this range. This goes down to a 95% chance at 300m withint 5 seconds, which basically means you must be able to hit the head or chest area of your target possible multiple times.

Of coarse soldiers can't shoot this well, so your actual chances of surviving a firefight at 300m is actally quite high, so long as you don't do anything stupid.

As a foot note I like to point out the by incapacitation all that is ment is that the person stops fighting an is rendered ineffective. This may be through killing him, but is more likely to be through wounding or even just plain scaring the person so they can no longer operate.

If you want to know more, search for it. I've covered this topic in several posts now ;)

31st Jan 2002, 09:02 PM
I'd like to take this opportunity to point out that a lot of the things suggested here are beyond the practical capabilities of the UT engine. Furthermore, some of the things people would like to see implemented, while definitely realistic and ground-breaking, would be of little to no use when you're playing. Case in point: ballistics.

I had been doing ballistic tables for every projectile using specific ballistic coefficients, velocities, and zero ranges using a ballistic calculator. The result was a fairly accurate representation of the flight path of every bullet. This was VERY time consuming and quite frankly, I didn't know if the information would be of any use since I had no idea how UT handled ballistics. Through eventual discussion with Warren and Beppo we concluded that such a complex ballistic system was far too much work with very little benefit. No one really, except programmers, would notice a difference, and being able to claim a "super-accurate ballistics system" took a back seat to more pressing matters.

That said, the Unreal 2 engine up and coming with it's much-improved physics system will probably provide for simpler implementation of things like this. In the meantime, you'll have to be happy with what we've given you so far. We could spend a few more weeks fine-tuning ballistics and implementing a wounding system, then working out the bugs and modifying it from the complaints invariably spewed forth by forum nitpickers, but we didn't think the community would like that.

31st Jan 2002, 09:12 PM
Mmmmm... sounds like good news to me Gryphon.

31st Jan 2002, 09:13 PM
har har! n1 gryph

31st Jan 2002, 09:19 PM
i agree- i also want to see bullet holes appear on the models. thats realistic (and also textures, such as walls and such, and if you say there are bulletholes on walls etc. i dont ever see them)

31st Jan 2002, 10:02 PM
Bullet holes most definitely appear on walls. You probably have detail set to a lower level which eliminates decals, or you're using a Mac. If it's the latter, oh boy...can't help ya there. ;)

You'll all be pleased to know 2.87 has some REALLY awesome looking bullet holes, specifically drawn to suit the material being shot.

31st Jan 2002, 10:20 PM
Wounding system would be very cool. For the next release (after 2.87), are you guys gonna be working on that, among other things?

31st Jan 2002, 11:35 PM
wow, thanks for all of the responses and expertise!

I guess the lack of 'penalty' for hitting an object would explain why I was killed by Robar on the old bunkers map while standing behind the concrete bunker. The Robar round didn't lose velocity nor stop even after going through two walls.

So in effect, with the current UT engine, a bullet could go through countless walls and bodies, from one end of the map to the other? So, on the old bunkers map, for example, someone could stand behind a bunker armed with a supressed p90. Then spray on auto while firing towards the enemy's side, and potentially kill someone standing behind the opposite bunker? That's 4 walls!

Ah, but thanks to all of the technical expertise lent here, I have a better understanding of the limitations.

1st Feb 2002, 12:26 AM
No no no, the bullets are not allowed to penetrate though a certain distance. Try it with a thick pole and a thin one (or the very edge of a crate), the thin one will get bullethits on the other side, the thicker ones do not.

1st Feb 2002, 02:09 AM
soo....the distance penetrated is cumalative (sp?)? IE may penetrate two boxes, but not three, all of the same thickness?

1st Feb 2002, 08:57 AM

It all comes down to object thickness. If the bullet can pass through the object it is uneffected. If it can't penetrat the object it is stopped.

If a rate can be penetrated, it doesn't matter how many you line up, they all will be penetrated.

I am reading the code right here, aren't I Yurch?

1st Feb 2002, 01:07 PM
Actually I believe a projectile in Inf. has X units of total penetration.

Say you have a projectile which penetrates 16 units, and 3 walls 6 units each. It will pass through the first two, and be stopped in the third.

But in any case some coder will probably tell us we're all wrong ;)

[edit] if bullets penetrated through the whole map, Inf. wouldn't be much fun to play online...

1st Feb 2002, 01:32 PM
My pic was of course a bit exaggerated.

And BA Baracus did some penetration tests.

another new INF means another "shooting through walls" update (http://forums.beyondunreal.com/showthread.php?s=&threadid=81246)

BTW where is he? His last post date is November 30th, 2001 10:20 AM.

1st Feb 2002, 01:38 PM
I honestly dont know about this in inf.
but I was doing a test once in unreal ed.
(was half done making a bridge, killing time :p and there was a bit where 3 semi masked brushes were lined up parrallel. )

each wall was, if I recall correct) somewhere between 10 and 15 points thin.

tried the beretta an 5-7, they wouldent penetrate.
the de whent through, so did the m-16 and everything else.

tried on two walls (about a 20 foot gap inbetween)
de got stopped, so did mp5.
m-16, sig, famas, psg whent through.

tried it on 3 walls. only the robar whent through.
total of 30 to 45 points I think.

I dont know the software or what really happened.
Im just looking at the 2.86 decals and saying what I saw.

1st Feb 2002, 02:04 PM
Looking at another function, there might be more to the penetration then we thought. It does seem to slow down a bit after penetrating objects, and its damage seems slightly reduced too. Hmm. (I am looking at the TouchMe function in the flying state, not sure if I gave you that, Tiffy) I don't know quite how effective it is, of course, its quite complicated.
But, tiffy is correct in the penetration. It is recalculated using the same MaxWall every time it hits something, so it could pass through two poles of thickness 3, but not through one pole of thickness 6.

1st Feb 2002, 05:18 PM
Really... I could swear I've seen them get stopped by a series of thin objects...

1st Feb 2002, 05:33 PM
my test was far from scientific, lol
thats just how it looked to me, at that time on that map.

maybe a bit more detailed testing is in order.

1st Feb 2002, 07:23 PM
each of these plates is 10 points thick.

1st Feb 2002, 07:26 PM

1st Feb 2002, 07:27 PM

1st Feb 2002, 07:31 PM

1st Feb 2002, 07:33 PM
?? thats definatly not what I posted??
try again

1st Feb 2002, 07:50 PM
in this one, each plate is 5 points.
so yea, it seems cumilative.

note: this does not reflect killing power. just that the game placed a decal there.
weather you'd a been killed standing between plate 4 and 5, I dont have a clue.

1st Feb 2002, 07:54 PM
hmmm the DE seems to be more powerfull than i thought..

1st Feb 2002, 08:05 PM
Razz, that's beautiful! Hmmm, that deagle is powerful. And I didn't realize m-16s and sigs had decent penetrating power as well...

C.E.R.T. Boy
1st Feb 2002, 08:06 PM
I like what you've done here with the plates but...

You missed a few there buddy.

Maybe you need to spend less time on UnEd and some more time on the range. ;)


1st Feb 2002, 11:05 PM
I can see what the fuss is about now.

1st Feb 2002, 11:28 PM
Hmm, perhaps it is cumulative. I should look at that code again, thanks for testing it out.

2nd Feb 2002, 03:04 AM
damn, that p90 has some serious wall bashing power..
what the heck is the muzzle velocity on that thing. I have a hard time picturing a little round like that being just as effective as a robar...

2nd Feb 2002, 03:54 AM
That's the suppressor bug...

2nd Feb 2002, 07:46 AM
I think I'll join Yurch in looking at code.

Thanks for taking the time to test and post the results RAZZ, appreciated.

2nd Feb 2002, 07:56 AM
Nice stuff there FURY!!!!

2nd Feb 2002, 08:38 AM
that you SHIVA!! :p
(forum name systems a bitch, aint it ;) )

penetrations a very fiddly thing to interpret.
the rounds from a 5-7 were designed to go through vests, but not walls. the small low velocity round wont have the force to continue.
sharp knife, soft push.

de generates alot of hitting power. cause of its rounds design, it wont work well on vests even tho it can smash cinderblocks.
like a rusty ax. lots of push but dull edge.

I presume the materal to be something like concrete.

the map I used is here.
plates are 5 points thick in this one, its unchanged since the last robar/p90 test.

(for those who dont know hot to run it :p)
stick in maps, goto unreal and open the console.
type "open weproom"
theres only one spawn, so make sure bots are off ;)

2nd Feb 2002, 09:08 AM
More interesting tests...

Damage to a bot shot through X plates:

52 --> 0 plates

48 --> 1

43 --> 2

40 --> 4

37 --> 5

0 --> 6 [stopped]

60 --> 0

54 --> 1

49 --> 2

0 --> 3

Seems like penetration effects damage as well...

2nd Feb 2002, 09:30 AM
the unsuppressed P90 didn't go through the first plate???
I would have thought p90 penetrating more than DE magnum...
Interesting topic!

2nd Feb 2002, 10:30 AM
size of the round.
larger rounds transmit more power over range.

p-90 uses a small bullet.
smaller than the mp5/beretta, which I think (dident test yet) has the better wall penetration.

2nd Feb 2002, 10:33 AM
"size of the round.
larger rounds transmit more power over range. "

ok, but on the screenshot, it didn t go through the first.

2nd Feb 2002, 01:39 PM
The penetration dosent seem to change over range.
least not over the short ranges I tried it.
long as it reaches, it goes through.
(I'll make a longer box later and see)

personaly I suspect that to save time, the penetration value was averaged out.
only Yurch and the guys will be able to tell us for sure.

thickness has some effect here, im not sure which.

5-7 and beretta will go through one 5 point plate.
so their penetration is greater than 5, less than 10.
the p90 and mp5 will go through two 5 point plates.
so their greater than 10, less than 15.

but on the 10 point plates, they dont penetrate the first one.
meaning all 4 guns did less than 10 points.

maybe the thickness of a single plate ramps up the resistance.
so a 10 point plate behaves like 15 points.

2nd Feb 2002, 01:45 PM
Maybe the effect is sort of cumulative. Perhaps after the first plate, the round is only going 2/3s its original velocity, so it has less penetration power. But if it went through one solid plate twice the size, the plate would absorb the energy and stop it.

Oh, well. Just my two cents.

2nd Feb 2002, 02:14 PM
I just tried it.

de will go through 10, 1 point plates. (total 10 points)
but, it will also go through 2 10 point plates. (total 20 points)

supressed p90 stopped shy at 14 1pt plates. (14 points)
even tho it cuts through all the 5 point plates with ease.

Its up to Yurch and the guys to really solve this mystery.

2nd Feb 2002, 07:34 PM
Bullet penetration IRL is a rather complicated issue ..... it depens on hardness, weight, shape and speed of a bullet then there's also the material it hit's different effects for different materials, thicknesses or angles of impact ...... ( I was told never to shoot a gun in a tiled room....... )

<------- SHIVA

Dr. Beer
3rd Feb 2002, 02:15 AM
It does lessen the damage. I tested this like 6 or 7 months ago.

BA Baracus
18th Feb 2002, 10:59 PM
Hadmar said:
And BA Baracus did some penetration tests.

another new INF means another "shooting through walls" update

BTW where is he? His last post date is November 30th, 2001 10:20 AM.

well, lost my job in the post 9/11 slowdown. went back to school full time and work nights full time now. didn't leave a whole lot of free time but i was still around for a bit after that. then i started hosting my own website and shell accounts for my friends on my mac so i could no longer reboot into OS 9 to play INF(unplayable in Classic). twas a sad sad thing, but at least grand theft auto 3 was there for me :) i'd still occasionally read the forums but that dropped off too once the new semester started.

but, now that selling plasma brings me an extra $200 a month, i went ahead and played to good little capitalist and just yesterday put a Dual 1Ghz G4 on the ol' credit cards. i don't get it for an estimated 6-8 weeks, but when i do my trusty B&W G3 gets deligated to dedicated server work instead of server/personal machine. freeing up the G4 for all the INF i can fit in. and well, the anticipation of being able to play INF again brought me back to the forums to see what was going on in the old place

it's good to be back!

and RAZZ, could you email me a copy of your test map? i can't seem to download it and i would LOVE to mess around in there when 2.87 comes out.

19th Feb 2002, 08:39 AM
I didn't read this thread but wanted to point something out. I've read quite a few books on the drug war and one of them was by a police officer. The first chapter was about a chase and the cops were shooting at the car, hitting the guy, but because the bullets had to go through the rear window and the drivers seat they weren't really hurting him. When he got up they saw a dozen or so bullets fall off his back.

(Note that a few seconds later the guy shot a luger through the passenger door and they were decently wounded)

19th Feb 2002, 10:32 AM
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19th Feb 2002, 11:01 AM
speaking of bullet, Gryphon said that impact holes would be better in 2.87 but I think those on the trailer were still the ugly UT ones ;) so what?

shouldn't the penetration depend mainly on the speed? then a 5.7 round should have a great penetration coeficient

that a bit off-topic but I once saw a 1milimeter dust fragment blow a 2 cm hole in a steel plate because it was thrown at the speed of a meteor ;)

BA Baracus
19th Feb 2002, 03:14 PM
shouldn't the penetration depend mainly on the speed? then a 5.7 round should have a great penetration coeficient

ok, i haven't taken a physics class in a long long time, but it's going to depend on the kenetic energy of the bullet, the hardness of the bullet, the hardness of the material shot and the thickness of material shot.

again, could be wrong here, but i believe Ke=mass * velocity(squared), so yes, velocity is an issue, but the low mass of the 5.7 round generally gives it poor penetration(though there are special properties of the bullet that give it great penetration against armour, i'm not going to get into that).

to give a greatly over exagerated example, it's estimated that when you sneeze the air and other particles leaving your body travel at around 100mph. however, it's going to be one hell of a lot harder to stop say, a car, travelling at only 10mph.

oh, and i would guess that the new bullet decals simply hadn't been implemented when the trailer was made.

19th Feb 2002, 05:16 PM
dang... my most popular map and I never backed it up :D

row on the left is one point plates, row on the right is 5 point plates.
when your in unreal (make sure your bots are off) type "open plates" into the console, and it should load.

19th Feb 2002, 06:00 PM
Although I am an Engineering Physics major at UC Berkeley, I can not say that I have been shot by a variety of bullets and have a vast, first-hand knowledge of internal ballistics. But, here's what I learned in Physics 7A:

F = (dP) / (dt)

F = force
P = momentum, which is mv
m = mass
v = linear velocity

So, an object exerts on impact a greater force on a surface, if it's initial momentum is greater. Since momentum is jointly proportional to mass and linear velocity, the heavier the object and the faster it is traveling, the greater force it exerts on impact.

But here's another thing... exerting a lot of force on a surface is only one factor in penetration. You won't penetrate a piece of paper, if the force is applied over the entire surface of the paper!

So another factor is the cross-sectional area of the impact surface.

To achieve maximum penetration, you must exert the most force possible over the smallest area possible, in other words, go for maximum point-pressure.

I mean, what's easier: hammering a flat coin into the wall with a small hammer, or a pointy nail into the wall with a big hammer?

But common sense coult have told you that.