Armor penetration model

[demosthenes]

Hi Graviteam,

I want to know how high fidelity the armor and projectile interaction model is.

Could you list everything that is modeled, such as spalling, armor hardness, armor quality, weakspots, projectile richochet and degradation, ammo quality etc. ?

I'd also appreciate if you could explain each step of the process when something hits your tank, such as how you calculate line of sight thickness, penetration, and kill probability.

Thanks for reading.

P.S Will your games come out on Steam?

[andrey12345]

Could you list everything that is modeled, such as spalling, armor hardness, armor quality, weakspots, projectile richochet and degradation, ammo quality etc. ?

spalling - no
weakspots, projectile degradation - ?? what is it

armor hardness, armor quality, projectile richochet and degradation, ammo quality - yes

I'd also appreciate if you could explain each step of the process when something hits your tank,

It's be like long theoretical book 
Sorry but i don't know English so good to write so much text.
If you have more detailed questions - write, I try to answer.

such as how you calculate line of sight thickness, penetration, and kill probability.

"line of sight thickness" - what is it?
Penetration calculated through formulas "from books" for many shell types.

Our model don't use any kill probability (it's totally bad and incorrect thing). They calculated penetration as determinate process in any case.

P.S Will your games come out on Steam?

No

[Donken]

I think by line of sight thickness is for example if you angle your tank so the theoretical armor thickness gets higher (like sloped armor) Tigers in WW2 is a good example when they angled themselves 45 degrees from front to get higher los thickness

[andrey12345]

I think by line of sight thickness is for example if you angle your tank so the theoretical armor thickness gets higher (like sloped armor) Tigers in WW2 is a good example when they angled themselves 45 degrees from front to get higher los thickness

It is not necessary if you use very complicated formula for the calculation (like in our game). Angle are usually taken into account automatically as the argument.

[Flanker15]

spalling - no
weakspots, projectile degradation - ?? what is it

Weakspots like hatches and viewports, The armor thickness is painted on like a texture so I'm pretty sure they're there.

Projectile degradation I guess is the shell fragmenting and slowing down after it hits something reducing it's penertration of more armor.

No spalling but is there fragmentation from the shell?  I've had a SABOT go through a target at the back but injure crew at the front away from the shell path.

Also will the game engine ever have exit hole decals for hits?

[Flashburn]

Projectile degradation

 

Shells loosing velocity in flight?  Ie Ballistics?  Uh yes, if that is what that means.   

Well its damned good, ie every graviteam game has had it.  t72, k42, k43, APOS, SABOW. .............whatevers next................

[demosthenes]

I could have explained better, but by projectile degradation I meant if stresses like fracturing and the sharp penetrator tip being eroded are modeled on the projectile once it hits armor.

Line of sight thickness = толщина брони по ходу снаряда

It's be like long theoretical book  Grin
Sorry but i don't know English so good to write so much text.
If you have more detailed questions - write, I try to answer.

Well, I was looking for something like this, which is from the arcade game world of tanks:

"First the server checks if there is a ricochet. And as I mentioned before all projectiles will ricochet if the angle of the hit is lower than 10 degrees, with one exception when the thickness of the armor is 3 times lower than the caliber of the projectile. So if there is no ricochet the projectile is rotated to normalize the angle and we proceed to calculate the thickness of the armor under the given slope (thickness/cosine of the angle between armor and the projectile - not 100% correct but close enough for an arcade). After that we check the table to see what armor-penetration capability the projectile would have at a given distance. The number we get is modified by gaussian(normal) distribution limited by +/- 30%. And finally we compare it to the armor thickness we calculated in the second step. If piercing number is higher we get penetration, if lower - ding.

Example: We have 100mm armor. And let's say the projectile with armor-penetration of 120mm on given distance can get through 110mm of armor. Let's say because of the impact angle the armor got "thicker" to 121mm. We roll the dice (distribution) and with some probability the penetration capability of the projectile might change to 110+/-33mm. If it changed to 121 and above - we get penetration. If below - ding."


If something like that is too much to type in English, I understand. I could read it in Russian though.


BTW, if a component such as the engine or transmission gets hit, does it get fully disabled 100% of the time, or could it still barely work with much lower performance? There are many anecdotes where tank engines get hit but they still keep working.

Thanks for taking the time to reply Andrey

[andrey12345]

Weakspots like hatches and viewports,

Yes

Projectile degradation I guess is the shell fragmenting and slowing down after it hits something reducing it's penertration of more armor.

Yes

No spalling but is there fragmentation from the shell?  I've had a SABOT go through a target at the back but injure crew at the front away from the shell path.

Yes fragments are flying too.

Also will the game engine ever have exit hole decals for hits?

No. Only enter decals.

[andrey12345]

Line of sight thickness = толщина брони по ходу снаряда

It is not necessary when using the correct formula, it turns by itself.

Well, I was looking for something like this, which is from the arcade game world of tanks:

Our version is much longer, and for some of 10 different types of projectiles it's own.

Example: We have 100mm armor. And let's say the projectile with armor-penetration of 120mm on given distance can get through 110mm of armor. Let's say because of the impact angle the armor got "thicker" to 121mm.
We roll the dice (distribution) and with some probability the penetration capability of the projectile might change to 110+/-33mm. If it changed to 121 and above - we get penetration. If below - ding."

It's wrong way to simulation suitable may be only for arcade game.
More or less normal way is through the receipt of the velocity (energy).

And most importantly, the definition of penetration / no penetration is essentially a secondary factor, we are interested in what will be under armor, and what remains in front. Actually penetration / no penetration - is largely conventional. The main task - the impact of fragmentation field to the aggregates and crew under armor.

BTW, if a component such as the engine or transmission gets hit, does it get fully disabled 100% of the time, or could it still barely work with much lower performance? There are many anecdotes where tank engines get hit but they still keep working.

It's can be partially damaged.

[demosthenes]

BTW, does the game model failure of fuzes? If yes, at what angle will the 115mm HE and HEAT fail to detonate?

Dumb question, but what are the yellow arrows I see pointing out from the armor in statistics mode?

[andrey12345]

BTW, does the game model failure of fuzes? If yes, at what angle will the 115mm HE and HEAT fail to detonate?

Yes of course and for APHE too.

Dumb question, but what are the yellow arrows I see pointing out from the armor in statistics mode?

Normals to "surface"

[demosthenes]

Is that the actual projectile normalization as your engine simulated it happening, or is it some kind of abstraction?

[andrey12345]

Is that the actual projectile normalization as your engine simulated it happening, or is it some kind of abstraction?

Normal it's normal, not a normalization
http://en.wikipedia.org/wiki/File:Surface_normal.png