Damage Model Bug Stomping - Part 2

[Woke Up Dead]

Originally Posted by majorfailure

I don't think the Yak family stands out for being tough because the Bf109 is so fragile. It stands out for being tough because it has an inline engine that is close to indestructible - while other planes, notably the P-40 and P-51 (though Bf109 not far off - and don't let me get started about the MiG-3 series - that thing burns no matter where and what hit it) have engines that regularly die from a few rifle caliber bullet hits.

Yak engines don't die, but they do sometimes go to an "almost dead" state when hit where they only get 5-10% of normal power out of them; only good enough to extend your glide towards home a little bit. But to the outside observer it may look like the engine is not damaged because it's not smoking, the prop is still spinning, and the engine is making a little bit of "running" noise.

[Pursuivant]

Originally Posted by majorfailure

Fw190s do obviously suffer from overdone damage from a few hits - while quite alot of hits are survivable, though the landing will be no fun.

Agreed. My impression of the FW-190 series is that "they're easy to bend, hard to break."

Originally Posted by majorfailure

I don't think the Yak family stands out for being tough because the Bf109 is so fragile. It stands out for being tough because it has an inline engine that is close to indestructible

Respectfully, I disagree. Please play the mission I've uploaded, choosing any of the Yak series as your targets, and you'll see that their engines are actually quite fragile.

Because your posts are generally spot on, you had me worried that my tests were incorrect. So, I went back and tried shooting the Yak series fighters (Yak-1, Yak-3, Yak-9) from different angles. I repeatedly got the same result as I got before - about 1 second of .50 cal MG fire was sufficient to trigger engine failure and/or fire, and to convince the AI pilot to bail out. The Yak-9 is only tougher than the other Yaks because engine fires tend to quickly self-extinguish.

The important trick is to aim for the first third of the front fuselage - just behind the propeller spinner. Hits further back on the front fuselage - just ahead of the pilot - hit the guns or parts that aren't modeled.

Additionally, there seems to be some randomness or error built into damage results, so there will be times when some parts just won't break. You have to "fly" the same mission 4 or 5 times before you can start getting a sense of where the average lies.

Originally Posted by majorfailure

other planes, notably the P-40 and P-51 (though Bf109 not far off - and don't let me get started about the MiG-3 series - that thing burns no matter where and what hit it) have engines that regularly die from a few rifle caliber bullet hits.

Agreed. Inline engines are far too vulnerable across the board.

Originally Posted by majorfailure

Wings may be too fragile, but Yaks are small and light, so damage should harm them more than bigger, tougher planes.
Bf109 not tough -yes. But maybe that is okay, there is nearly no part of that plane that can be hit without damaging something of value.

But, I'm consistently seeing results where just 5-10 .50 caliber bullets scattered across a Yak's (or Bf-109's or Spitfire's) tail surfaces or wings will trigger collapse when it's sitting on the ground. Basically, the plane falls apart because you punched half a dozen or a dozen random 1 inch/25mm-wide holes into several square yards/meters of aluminum or plywood.

Yes, realistically, those 5-10 bullets might break a part, but only if they all hit in the same place while the aircraft was pulling high-G maneuvers. Scattered across a wing or control surface, that sort of damage result makes no sense.

[majorfailure]

Originally Posted by Pursuivant

Respectfully, I disagree. Please play the mission I've uploaded, choosing any of the Yak series as your targets, and you'll see that their engines are actually quite fragile.

Because your posts are generally spot on, you had me worried that my tests were incorrect. So, I went back and tried shooting the Yak series fighters (Yak-1, Yak-3, Yak-9) from different angles. I repeatedly got the same result as I got before - about 1 second of .50 cal MG fire was sufficient to trigger engine failure and/or fire, and to convince the AI pilot to bail out. The Yak-9 is only tougher than the other Yaks because engine fires tend to quickly self-extinguish.

The important trick is to aim for the first third of the front fuselage - just behind the propeller spinner. Hits further back on the front fuselage - just ahead of the pilot - hit the guns or parts that aren't modeled.

Additionally, there seems to be some randomness or error built into damage results, so there will be times when some parts just won't break. You have to "fly" the same mission 4 or 5 times before you can start getting a sense of where the average lies.

Last campaign I played I shot down a few (hundred or so) early war Yaks of all colours - and it may be my aiming, but I rarely got their engine. Pilot dead, controls shot out, structural damage leading to crash were IMHO the most common deaths, structural total failure of fuselage or wings also common.
Fuel tanks punctured and engine losing a little or some power, smoking, total kaboom, seen that happen.

Vs. P-40, engine dead is among the most common deaths, vs. Bf109&Mc202 too. Vs MiG-3 it is about the only death -though I sometimes think there must be a fuel tank behind the engine that burns like that, vs. LaGG it happens at least to be noticed.

Just form feeling, I'd say Yak has highest initial turn rate of all of these, high speed, good roll, small plane. I may be aiming for the same point I would get good hits on a P-40 - but I may end up a little too far and hit pilot/tail section, or wings (if aim not on center but off left/right). So maybe in the end it is ME that is responsible for not getting engine dead regularly on a Yak.

Originally Posted by Pursuivant

But, I'm consistently seeing results where just 5-10 .50 caliber bullets scattered across a Yak's (or Bf-109's or Spitfire's) tail surfaces or wings will trigger collapse when it's sitting on the ground. Basically, the plane falls apart because you punched half a dozen or a dozen random 1 inch/25mm-wide holes into several square yards/meters of aluminum or plywood.

Yes, realistically, those 5-10 bullets might break a part, but only if they all hit in the same place while the aircraft was pulling high-G maneuvers. Scattered across a wing or control surface, that sort of damage result makes no sense.

Put like that it seems weak, though from ingame performance, sitting in a Yak as well as shooting at Yaks I never percieved them as structurally especially weak except when you try to dive them.

[Pursuivant]

Originally Posted by majorfailure

Last campaign I played I shot down a few (hundred or so) early war Yaks of all colours - and it may be my aiming, but I rarely got their engine. Pilot dead, controls shot out, structural damage leading to crash were IMHO the most common deaths, structural total failure of fuselage or wings also common.

Due to the distances and angles at which I was firing, and because I'm fairly confident that IL2 models armor correctly, I didn't test crew vulnerability. (Realistically, at <50 m a .50 caliber AP shell should penetrate at least 26-28mm of armor.) Other than that, your experience squares with my tests for the Yak-1 & Yak-7.

Originally Posted by majorfailure

Fuel tanks punctured and engine losing a little or some power, smoking, total kaboom, seen that happen.

In the earlier planes in the game, explosion is a very common "fatal damage" effect, even for parts of the plane that realistically wouldn't explode. Fuel tanks will also explode if they take enough damage - which might or might not be realistic depending on the aircraft.

Originally Posted by majorfailure

Vs. P-40, engine dead is among the most common deaths, vs. Bf109&Mc202 too. Vs MiG-3 it is about the only death -though I sometimes think there must be a fuel tank behind the engine that burns like that, vs. LaGG it happens at least to be noticed.

Most inline engines will have a big oil tank just behind the engine. That tank is typically quite vulnerable to gunfire and will sometimes even explode.

My tests show that the MiG-3 series is about as vulnerable to wing and tail damage as the Yak 1, 3 or 7 series. The engine is a bit tougher than the Yaks, but not by much.

Originally Posted by majorfailure

So maybe in the end it is ME that is responsible for not getting engine dead regularly on a Yak.

Fly on arcade mode using the QMB to test your gunnery accuracy. In the absence of realistic damage textures which show exactly where each bullet hits, that's the only way to do it.

Originally Posted by majorfailure

Put like that it seems weak, though from ingame performance, sitting in a Yak as well as shooting at Yaks I never percieved them as structurally especially weak except when you try to dive them.

Keep in mind that I was shooting at aircraft sitting on the ground -1 G of positive G force, no wind resistance. Other than recording breaking parts, I have no way of knowing how damage effects affect a flying aircraft.

[Furio]

Once, I was shot down by a couple of bullets in the nose of my plane. Tac -tac, and the engine began immediately to emit creaking and squeaking sounds, losing power and stopping after a couple of minutes… The gun was an Mg15 (Stuka gunner) and my plane an armoured Il2… Hardly realistic.

In another occasion, while flying with a cannon armed La5, I set on fire a PZL P11. It burned furiously, and went ahead for a loooong time flying excellent evasive manoeuvres without any hint of diminished performances (or pilot’s cooking).

I think sometimes strange things happen, and are almost certainly result of random errors, having nothing to do with damage models. I think that reports about single events are of little value. What we need are consistent experiments, repeatable by others, like a sort of peer review. Pursuivant demonstrates that can be done, and that results are sometimes surprising.

I believe that further test will bring more surprises. And also think that Il2 remains a fantastic game, still a lot of fun after so many years, a monument to original developers and to the continuing work being done today.

[majorfailure]

Originally Posted by Furio

Once, I was shot down by a couple of bullets in the nose of my plane. Tac -tac, and the engine began immediately to emit creaking and squeaking sounds, losing power and stopping after a couple of minutes… The gun was an Mg15 (Stuka gunner) and my plane an armoured Il2… Hardly realistic.

Can get even worse. PK from Bf110 rear gunner in an IL-2, that's as impossible as it gets.

Originally Posted by Furio

I think sometimes strange things happen, and are almost certainly result of random errors, having nothing to do with damage models. I think that reports about single events are of little value. What we need are consistent experiments, repeatable by others, like a sort of peer review. Pursuivant demonstrates that can be done, and that results are sometimes surprising.

Yes. Totally agree. Once is almost never. And data is always better as impressions&conjecture, I think I inadvertently proved that with my last post.

Originally Posted by Furio

I believe that further test will bring more surprises. And also think that Il2 remains a fantastic game, still a lot of fun after so many years, a monument to original developers and to the continuing work being done today.

I'll drink to that. Cheers!

[Janosch]

Originally Posted by majorfailure

Can get even worse. PK from Bf110 rear gunner in an IL-2, that's as impossible as it gets.

So a pilot can die if hit by a machine gun? Madness!

[Pursuivant]

Originally Posted by majorfailure

Can get even worse. PK from Bf110 rear gunner in an IL-2, that's as impossible as it gets.

Not impossible, just unlikely.

The IL2 had ~5mm of armor around the cockpit sides and just behind the canopy, plus armor glass at the front and a heavier armor plate behind the pilot's head.

At close range (i.e., 100 m or less) a 7.62mm AP bullet can punch through the side armor, even at an angle.

This thread nicely explains penetration of German 7.62mm bullets vs. armor plate and aircraft aluminum:

http://forum.axishistory.com/viewtopic.php?t=72990

[Pursuivant]

Originally Posted by Furio

The gun was an Mg15 (Stuka gunner) and my plane an armoured Il2… Hardly realistic.

I beg to disagree. The IL2's armor makes it very tough, but not invulnerable. There are gaps in its armor which you can exploit.

It is quite vulnerable to hits to the oil cooler and coolant radiator. The sort of damage you describes perfectly matches the effects of a hit to either of those.

Additionally, there are gap in the armor where the exhaust stacks emerge from the engine - so a hit there will quickly stop the engine.

Originally Posted by Furio

In another occasion, while flying with a cannon armed La5, I set on fire a PZL P11. It burned furiously, and went ahead for a loooong time flying excellent evasive manoeuvres without any hint of diminished performances (or pilot’s cooking).

The PZL P.11c is one of the worst modeled planes in the game. Only the Me-323 is worse. While my tests can't test for effects on crew (other than death, injury or bail-out), it wouldn't surprise me in the least if the modeling for the P.11c doesn't include instructions that cause fire damage to damage the pilot.

That said, the P.11c had the unusual ability to jettison the fuel tank in event of a fire. Realistically, if you're in a burning P.11c, you dump the fuel tank and try to glide away from the fight.

Originally Posted by Furio

I think sometimes strange things happen, and are almost certainly result of random errors, having nothing to do with damage models.

Occasionally, I'll load up the game and discover that parts that broke before refuse to break, or are harder to break. There's some randomness deliberately built into damage models - and there should be - but occasionally I think that there's just an error in the program.

Originally Posted by Furio

I think that reports about single events are of little value. What we need are consistent experiments, repeatable by others, like a sort of peer review.

Speaking of which, I welcome peer review. Don't just take my word about damage results, please try to reproduce them!

[Pursuivant]

Originally Posted by Woke Up Dead

Yak engines don't die, but they do sometimes go to an "almost dead" state when hit where they only get 5-10% of normal power out of them; only good enough to extend your glide towards home a little bit.

My tests can't test for reduced power output, other than determining if the prop speed is reduced.

But, my impression is that many engines - particularly radials - behave as you describe. It's not just Yaks.