Material penetration modelling? Can anyone explain this to me?

[Grumpy 0]

Hi all,

I'm writing a review of Arma2: Combined Operations, and I'm trying to get some technical details on the Material Penetration Modelling (MPM) mentioned on the features page at the Official ArmA2 website.

I've asked my press contact at Bohemia twice for further details but only get more press releases in reply ... no details on the MPM.

For example, is the MPM modelling just the thickness of steel on each type of vehicle and object; or, perhaps, does the MPM also model, say, the angle of incidence an incoming projectile like an RPG may have when it strikes a body plate on a vehicle like an LAV? Furthermore, does the MPM effects only apply to vehicle-projectile interactions, or does it also apply to soldier-projectile interactions? I do know, from first-hand in-game experience, that rifle bullets seem to have less killing power of AI soldiers at longer ranges.

Basically, I'm trying to get as many details about how the MPM works. Any help in this regard would be most welcome :)

[maturin 12]

There is no penetration system for vehicles. Maybe you can shoot things through cars, but that could be the doing of ACE for all I know.

Sabot rounds routinely go through tanks but that has nothing to do with the armor or the amount of damage dealt.

I'd assume that MPM refers solely to penetration of static objects but projectiles. Thin fences and corners of buildings are penetrated by bullets, that sort of thing. Angle of incidence matters a lot for ricochets.

[max power 21]

I must beg to differ with Maturin.

http://community.bistudio.com/wiki/Bullet_penetrability

http://community.bistudio.com/wiki/ArmA:_RVMAT#Surface_physical_properties

http://community.bistudio.com/wiki/Mondkalb%27s_Addon_Tutorial#TUT_Concrete.bisurf

http://community.bistudio.com/wiki/Damage

http://community.bistudio.com/wiki/Weapons_settings

A gloss over these pages should give you a fair idea of what's going on when you hit an object with a weapon. My own personal experience with the system is that a .50 caliber BMG round will go in one side of a car and out the other but a 5.56 will not, and a 14.5mm cannon firing ap rounds will kill the occupants of a BMP2 without damaging the vehicle much given the correct hit location.

I don't think it models armour penetration due to angles of impact by explosively formed penetrators, but it does do some work on ballistic projectiles provided the target is correctly configured. I don't think that weapons can perforate people like they do vehicles, though... at least I haven't experienced anything like that.

Edited November 22, 2010 by Max Power

[Grumpy 0]

Maturin and Max Power,

Thank you both for your replies.

Max Power, those links you provided are brilliant. Thanks so much for those. I can see now how the material penetration modeling is implemented.

I doff my cap to you because I thought I had some pretty good Google Fu but those pages you posted eluded me. I see now, however, that by simply going to the Community Wiki and using its built-in search with the phrase "material penetration" finds all the pages you posted. Who'd've thunk it?! :bounce3:

When I get my review completed I'll post a link here (if that's okay with the mods ... I won't if that's considered spamming).

[maturin 12]

a 14.5mm cannon firing ap rounds will kill the occupants of a BMP2 without damaging the vehicle much given the correct hit location.

If you're not running ACE, I'll eat my hat. Arma 2 has a penetration system for static objects, but penetration of armored vehicles is incidental and unrelated to the very basic hitpoint system.

[max power 21]

If you're not running ACE, I'll eat my hat. Arma 2 has a penetration system for static objects, but penetration of armored vehicles is incidental and unrelated to the very basic hitpoint system.

Vanilla ArmA2. This happened repeatedly to me in the campaign forcing a mission restart since members of team razor must not die, and they can't all fit in the same tank.

I doff my cap to you because I thought I had some pretty good Google Fu but those pages you posted eluded me. I see now, however, that by simply going to the Community Wiki and using its built-in search with the phrase "material penetration" finds all the pages you posted. Who'd've thunk it?! :bounce3:

It probably took me a little longer to get that information than you did when you searched the wiki. I was searching for '.bisurf' and I had to dig through some layers to get the pages that were needed.

Edited November 22, 2010 by Max Power

[Xenios 0]

If you're not running ACE, I'll eat my hat. Arma 2 has a penetration system for static objects, but penetration of armored vehicles is incidental and unrelated to the very basic hitpoint system.

I hope you've got a very edible hat, because there absolutely is a penetration system for vehicles in vanilla Arma 2 OA. :)

You can test it yourself in the editor. Place a very lightly armored vehicle like a BRDM or BTR-70 and set it to zero ammo so you can test without get gunned down immediately. Place yourself next to the BRDM with a Barrett and fire into the turret and drivers positions. The crew will die if you hit them, and you can now commandeer a perfectly intact vehicle. A .50 cal. round will pass right through the thin steel armor or armor glass without significantly damaging the vehicle itself, just as it would in real life.

The vanilla system is still not as good as the system in ACE 2, but it's come a long way from Arma 1.

[maturin 12]

I hope you've got a very edible hat, because there absolutely is a penetration system for vehicles in vanilla Arma 2 OA. :)

Keyword OA. Lemme go try things out.

Edit: Just put 20 M107 rounds right where the BRDM driver's head should be. Aside from one hit magically popping a tire, all crew members were perfectly healthy.

So it's an OA feature, and BI seem to be learning, slowly, from ACE 2.

Edited November 23, 2010 by maturin

[max power 21]

Keyword OA. Lemme go try things out.

Edit: Just put 20 M107 rounds right where the BRDM driver's head should be. Aside from one hit magically popping a tire, all crew members were perfectly healthy.

So it's an OA feature, and BI seem to be learning, slowly, from ACE 2.

It's not an OA feature, I told you already. This happened when I was first playing Harvest Red. I ordered ArmA 2 from Britain the day it came out there, and finished Harvest Red not long after that.

[maturin 12]

It's not an OA feature, I told you already. This happened when I was first playing Harvest Red. I ordered ArmA 2 from Britain the day it came out there, and finished Harvest Red not long after that.

I also died inside a BRDM once. But I can't reproduce it through any rational method. Can you?

I'm more inclined to think it was a glitch or a fluke. (Such as when turned-in passengers get killed by small arms fire hitting turned-in crew.)

Just put 20 .50 AP rounds a BRDM's open window in Arma 2 1.08, no mods.

The ACE team doesn't seem to think that Arma 2 has any built-in penetration system either. At least not one they built on.

[max power 21]

I also died inside a BRDM once. But I can't reproduce it through any rational method. Can you?

I'm more inclined to think it was a glitch or a fluke. (Such as when turned-in passengers get killed by small arms fire hitting turned-in crew.)

Just put 20 .50 AP rounds a BRDM's open window in Arma 2 1.08, no mods.

The ACE team doesn't seem to think that Arma 2 has any built-in penetration system either. At least not one they built on.

It has happened a number of times, consistently when a brdm opened fire on me in my brdm 2 with the 14.5 mm cannon.

edit: Speaking to your scientific reproducibility, the documents talk about armour refracting and reflecting bullets. Also, the driver may not be exactly where you think he is. For these reasons, I would try to pepper the vehicle with an autocannon in various places and see what happens rather than going the sniper rifle route first off.

Edited November 23, 2010 by Max Power

[Arksa 10]

Well the brdm front window is open when engine is off so there's your window of opportunity to shoot the driver.

[max power 21]

Well the brdm front window is open when engine is off so there's your window of opportunity to shoot the driver.

I think the front window is open when the engine is on- or else the driver wouldn't be able to see.

I've never had much luck shooting the crew through the armour glass on the front of that thing. The last time I tried to shoot the crew through the window though was in ArmA 1.

Edited November 23, 2010 by Max Power

[Big Dawg KS 6]

Launch OA and try the following:

Place a manned Military Offroad (M2) and put a few 9mm rounds into the driverside door. Compare the results with those of 5.56/5.45, and then 7.62.

Furthermore, a .50/12.7mm can penetrate the windows and side armor (killing crew memebers) of a BRDM-2, and the armor of BTR-40s. Same for the side armor of BTR-60s (tested firing into the gunner's seat). It even works on M113s, but because of what I mention below, only on the crew members that are turned out (M113 gunner is perminantly turned out).

Penetration system for vehicles is definately in place, however on most armored vehicles the crew proxies are not present when they are turned in (same goes for cargo or crew positions that can't turn out), so they aren't physically there to get hit by the penetrating rounds. This goes back to OFP days I suppose, when there was no reason to have proxies for crew positions that aren't visible from outside the vehicle...

Perhaps provided tweaked models with internal crew proxies, you will see realistic penetration (as far as crew casualties) for armored vehicles.

Edited November 23, 2010 by Big Dawg KS

[maturin 12]

Launch OA and try the following:

Place a manned Military Offroad (M2) and put a few 9mm rounds into the driverside door. Compare the results with those of 5.56/5.45, and then 7.62.

Furthermore, a .50/12.7mm can penetrate the windows and side armor (killing the gunner) of a BRDM-2, and the armor of BTR-40s. Same for the side armor of BTR-60s (into the gunner's seat). It even works on M113s, but there's a problem concerning crew proxies on armored vehicles with turning in and out.

Penetration system for vehicles is definately in place, however on most armored vehicles the crew proxies are not present when they are turned in (same goes for cargo or crew positions that can't turn out), so they aren't physically there to get hit by the penetrating rounds. This goes back to OFP days I suppose, when there was no reason to have proxies for crew positions that aren't visible from outside the vehicle...

Perhaps provided tweaked models with internal crew proxies, you will see realistic penetration (as far as crew casualties) for armored vehicles.

This sounds reasonable. It could apply to Arma 2 as well. I fired a full M107 mag straight through the open front window of a BRDM. Although the interior is fully modeled, you can only see blackness from outside the vehicle.

If I hit it with a HMG too many times it would be destroyed outright, and the glitchy hit detection would pop tires, making the crew bail out.

I don't have any of those vehicles so I will go test with M2 vs. AAV and BMP.

Edit: Just fired the entire YakB 12.7mm payload of a Hind-D at a BMP-2 to completely zero effect. After 200 or so rounds the AAV exploded, but the crew was uninjured up to that point. A BRDM would have blown up in a few seconds.

If Arma 2 has penetration, it's poorly balanced (the side armor on a BMP can't withstand that much .50 AP) and there are no crew models in any of the light vehicles I tested. They are hovering in another dimension and safe from harm.

But hold the phone! 30mm AP succeeded in injuring the gunner of a BRDM through the turret. MaxPower says the same happened with 14.5mm, which is larger than the 12.7mm I was using. So it appears that either the BRMD cannot be penetrated by the .50 that destroys it in a few dozen hits, or that only the gunner and not the driver is present and vulnerable to harm.

Now further testing indicates that while both driver and gunner can be harmed by 14.5mm or 12.7mm, only hits to the turret can injure them. The hitboxes of the frontal and rear armor do not allow for penetration.

Edited November 23, 2010 by maturin

[max power 21]

The BIS BMP2 example from ArmA 1 has crew proxies in the fire geo LOD. The ArmA 1 BRDM 2 second run example model has no proxies in the fire geo LOD. I wonder if this has something to do with those effects.

Edited November 23, 2010 by Max Power

[Big Dawg KS 6]

This sounds reasonable. It could apply to Arma 2 as well. I fired a full M107 mag straight through the open front window of a BRDM. Although the interior is fully modeled, you can only see blackness from outside the vehicle.

I simple way to test if the OA penetration system is in place in ArmA 2 would be to try it on a vehicle with visible crew proxies. For example, a .50 through the hatch of a turned out BMP commander/gunner, or through the side of the driver's compartment while he's turned out. Even small arms (in the 7.62, 5.56, 5.45 range) would penetrate unarmored vehicles (car doors are good). If you can't get any kills this way then one can conclude it's exclusive to OA.

Edit:

After testing in ArmA 1.08, it seems that while there is some penetration in place, it's not as prominant as it is in OA. I was only able to get penetration kills on unarmored vehicles (a UAZ). If you run CO, you can see a clear difference even if you are using the ArmA 2 units.

Edited November 23, 2010 by Big Dawg KS

[KeyCat 131]

Interesting topic!

I don't think that weapons can perforate people like they do vehicles, though... at least I haven't experienced anything like that.

I'm not 100% sure but I think I saw something about penetration in the HitPoint class for men when glancing thru the A2:OA configs. Will see if I can find it again...

I'm also pretty sure I managed to kill two inf. standing close with one 12.7 mm bullet (would be easy to test in editor as well).

/KC

Edited November 23, 2010 by KeyCat

[Big Dawg KS 6]

Interesting topic!

I'm not 100% sure but I think I saw something about penetration in the HitPoint class for men when glancing thru the A2:OA configs. Will see if I can find it again...

I'm also pretty sure I managed to kill two inf. standing close with one 12.7 mm bullet (would be easy to test in editor as well).

/KC

Yes, it works on people. However it really slows the rounds down. A .50 won't be able to get through someone's torso, but limbs and headshots are fair game (heads still slow them down pretty significantly). Not sure about backpacks (you can shoot through them, but I don't know if it's actually penetration or just lack of fire geometry), but weapon proxies don't appear to have penetration applied: your rifle can stop a .50 without any harm to you.

Edited November 24, 2010 by Big Dawg KS

[KeyCat 131]

...but weapon proxies don't appear to have penetration applied: your rifle can stop a .50 without any harm to you.

Know what you mean and wished it was different. Happens to me regulary when sniping that I hit their weapon and nothing happens, been like that since OFP days and it gets my vote for improvement ;)

/KC

[maturin 12]

Know what you mean and wished it was different. Happens to me regulary when sniping that I hit their weapon and nothing happens, been like that since OFP days and it gets my vote for improvement ;)

/KC

Agreed. More than penetration I would like for the weapon to be disabled by a good hit. That would be a terrible thing to happen in the middle of a firefight, and would induce just the sort of panic and desperation that marks Arma 2 at its best.

Or you could do this:

:D

[Arksa 10]

I think the front window is open when the engine is on- or else the driver wouldn't be able to see.

I've never had much luck shooting the crew through the armour glass on the front of that thing. The last time I tried to shoot the crew through the window though was in ArmA 1.

yeah sorry I said it the wrong way around :bounce3:

AI kills me in the first shot through that damn window and its annoying.

[arthur666 10]

Agreed. More than penetration I would like for the weapon to be disabled by a good hit. That would be a terrible thing to happen in the middle of a firefight, and would induce just the sort of panic and desperation that marks Arma 2 at its best.

I too would like to see this. It's very rare in Arma2 that I pull my pistol out of necessity. Destroyable primary weapons would change that. But we would make sure that AI would panic - either flee, hide or run for the nearest free weapon.

[maturin 12]

I too would like to see this. It's very rare in Arma2 that I pull my pistol out of necessity. Destroyable primary weapons would change that. But we would make sure that AI would panic - either flee, hide or run for the nearest free weapon.

Unarmed AI always flee under fire. Including tanks without ammo or turrets.

[Grumpy 0]

Great discussion about the material penetration of vehicles.

I did some further testing of my own this evening and found several differences between stock ArmA2: Combined Operations and ArmA2: Combined Ops with the ACE mod running. I'm at the early stages of testing, so limited my trials to M-107 and MAAWs rocket rounds fired at close range through adobe building walls, free-standing concrete walls, and wood fences, and corrugated metal.

In stock ArmA2:CO, the M-107 rounds can't penetrate an adobe building's wall, or a brick building's wall (like the control tower on the airfield) and wound or kill an AI I placed on the other side, whereas running it with the ACE mod, it can penetrate these walls.

Free-standing concrete walls about 8-inches-thick are no match for the M-107 round in stock ArmA:CO or with the ACE mod, although in my tests it did take more rounds in stock ArmA:CO to get the kill of a hapless AI on the other side of the wall from the same standoff distance.

MAAWs rocket rounds will completely destroy a small adobe house in stock ArmA2:CO but leave an AI positioned inside unharmed. In ArmA2:CO with ACE running, a MAAWs rocket round fired from the same spot will only crack the wall of an adobe house, but it will wound the AI inside due to fragmentation of the interior wall.

As for the vehicle penetration, I hadn't gotten to that yet, and I am tempted to just go with the results you guys have posted, but I better run a few tests on my own just to see it first hand. :)