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  #681  
Old 09-23-2014, 08:51 PM
Woke Up Dead Woke Up Dead is offline
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Originally Posted by Pursuivant View Post
"all bullets are treated as being incendiary"

Thanks much for this information, since it sort of proves my point.
Doesn't it actually directly disprove your point? You say "all bullets are treated as incendiary" I show you they're not, you say "my point is proven?"

My research shows that at the beginning of the war incendiary bullets were in short supply for the RAF's .303 guns, but that by 1942 typical belting was 50/50 armor-piercing/some type of incendiary. This source shows that in 1944 German LMGs were also 50/50, while two out of three HMG bullets were incendiary: http://users.telenet.be/Emmanuel.Gus...n/fgun-am.html

Since belting can't change from year to year in the game it's probable that the designers chose mid-war or late-war belting for the guns, when incendiary bullets were available and highly used. In that case half or even 5/6 bullets having incendiary capabilities is historically accurate.

"You'll notice that there is no ball ammo in the mix for any of the guns listed. It isn't even modeled!"
Was ball ammo used in air forces? I could only find references to armor piercing, incendiary, explosive/incendiary, tracers.


"Different mission, same result:"
There's those two or three arrows down low that could have gone through one of the two underfloor fuel tanks, #47 and #48 in the diagram you supplied, assuming the layout of the fuel tanks is the same in the 1830 and the 1820 engined versions.

Last edited by Woke Up Dead; 09-23-2014 at 11:38 PM. Reason: corrected German HMG ratios
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  #682  
Old 09-23-2014, 11:11 PM
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TexasJG TexasJG is offline
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Has anyone looked into the java coding to see how ballistics are actually calculated?
Other than DT I mean...
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  #683  
Old 09-23-2014, 11:57 PM
Pursuivant Pursuivant is offline
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Quote:
Originally Posted by Woke Up Dead View Post
Doesn't it actually directly disprove your point? You say "all bullets are treated as incendiary" I show you they're not, you say "my point is proven?"
True. I didn't make my point clear. What I was trying to say was that there is an unrealistically high percentage of bullets that can start fires (tracer, incendiary, explosive) in the standard beltings. AP and ball ammo make holes in things, other types of bullets start fires.

So, if you look at the beltings, you have a very high percentage of bullets that can start fires.

Quote:
Originally Posted by Woke Up Dead View Post
My research shows that at the beginning of the war incendiary bullets were in short supply for the RAF's .303 guns, but that by 1942 typical belting was 50/50 armor-piercing/some type of incendiary. This source shows that in 1944 German LMGs were also 50/50, while two out of three HMG bullets were incendiary: http://users.telenet.be/Emmanuel.Gus...n/fgun-am.html
That squares with my research, too, but I'm sure that you've done more work on the subject.

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Originally Posted by Woke Up Dead View Post
Since belting can't change from year to year in the game it's probable that the designers chose mid-war or late-war belting for the guns, when incendiary bullets were available and highly used. In that case half or even 5/6 bullets having incendiary capabilities is historically accurate.
That makes sense. After all, IL2 models planes at the peak of their performance.


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Originally Posted by Woke Up Dead View Post
Was ball ammo used in air forces? I could only find references to armor piercing, incendiary, explosive/incendiary, tracers.
It was used for early war beltings by the RAF due to shortage of better bullets. I could also see it being used by other air forces which had supply problems, or for ground attack missions against personnel and light vehicles. But, getting good info is very hard and I'm not an expert.

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Originally Posted by Woke Up Dead View Post
"Different mission, same result:"
There's those two or three arrows down low that could have gone through one of the two underfloor fuel tanks, #47 and #48 in the diagram you supplied, assuming the layout of the fuel tanks is the same in the 1830 and the 1820 engined versions.
Possibly, but the two suspect bullets exited the side of the plane just behind the engine. They might have penetrated the turbocharger/fuel injection system, though, which could also have triggered a big fuel leak. In either case, I could possibly see the hits starting a big fuel leak.

There's also the issue of the bullet completely blowing through an engine cylinder to penetrate whatever is behind the cylinder. That's a lot of energy for a small caliber bullet at 200-300 m, even if it is AP.

But, the big problem is that I was consistently getting that particular result. When I post a screenshot, it might represent a sample of 10 or more trials. I don't post weird "on-off" results, since in combat anything can happen.

That said, I think that the H.75 series isn't bad in terms of damage modeling, although it might be a bit too vulnerable to control run hits, and like all the other planes in the game it's a bit too flammable in that bullets instantly start fires. I'm also still trying to determine which models had armor glass and self-sealing fuel tanks. There are just so many variants!
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  #684  
Old 09-24-2014, 12:11 AM
Pursuivant Pursuivant is offline
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Woke Up Dead inspired me to run a lot of QMB missions flying planes equipped with the R-1820 engine to see if it's problem with the engine or the DM for particular planes.

As I suspected, it's a DM problem with the Buffalo series, particularly the B-239 (old model, initially had problems with oil leaks) and Buffalo MkI (serious design flaw which meant that the engine was highly vulnerable to overheat, especially in the tropics).

The SBD had a reputation for ruggedness, which carries over in engine DM. The CW-21 was such a rare bird that it didn't have much of a reputation either way, and as a much later model in the game, the DM is better. DT does very good FM and DM work.

Again, screenshots are representative of trends - 10-20 missions flown in QMB.

Dauntless - takes a licking and keeps on ticking!

http://forum.1cpublishing.eu/attachm...1&d=1411517213

CW-21 Demon - a bit more vulnerable to engine damage, but not bad. I had far more problems with fires (unsealed tanks) and pilot kills (no forward armor).

http://forum.1cpublishing.eu/attachm...1&d=1411517213

F2A - Could the fact that it was a lousy airplane, forced into a role it was never designed to fill, which had to fight at a disadvantage against vastly superior foes have influenced DM decisions?

http://forum.1cpublishing.eu/attachm...1&d=1411517213
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  #685  
Old 09-24-2014, 01:01 AM
Woke Up Dead Woke Up Dead is offline
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Quote:
Originally Posted by Pursuivant View Post
True. I didn't make my point clear. What I was trying to say was that there is an unrealistically high percentage of bullets that can start fires (tracer, incendiary, explosive) in the standard beltings. AP and ball ammo make holes in things, other types of bullets start fires.

So, if you look at the beltings, you have a very high percentage of bullets that can start fires.

(...)

That makes sense. After all, IL2 models planes at the peak of their performance.
So in the end I think we agree while still thinking we're disagreeing. There might be too many incendiary bullets for 1939-1941 planes and scenarios, but by 1942 the beltings in-game start to look like like they did in the war. It would be nice if players or mission builders could pick their beltings, but that may not be so easily done.


"There's also the issue of the bullet completely blowing through an engine cylinder to penetrate whatever is behind the cylinder."
But without knowing what the modeled components look like, we can't actually tell what the bullet went through, right? I can't find the thread that showed an image of the components of a radial engine in-game, but I remember that it wasn't just a disk, it was detailed enough that there were V-shaped spaces between the cylinders. So a bullet could pass freely through the V to hit something behind the engine.


"But, the big problem is that I was consistently getting that particular result. When I post a screenshot, it might represent a sample of 10 or more trials. I don't post weird "on-off" results, since in combat anything can happen."
It could be that there are enough critical components modeled in and behind the engine that when you test the way you do (flying directly behind a bomber's six and eating bullets), you will consistently take critical damage.

To simplify things, think of the engine is a big, two-dimensional disk when you look at it head-on. What percentage of the disk's surface area is taken up by components that would cause decreased power, leaks, or other damage that you experience: 20%, 30%, 50%? Let's say that 25% of that disk is vulnerable. If you hit the disk with 3 bullets, your chances of hitting a critical component are already 58% (http://stattrek.com/online-calculator/binomial.aspx). If you assume that 30% of that disk is vulnerable, then your chances of sustaining damage with at least one of the 3 bullets is 66%. If half of that disk is vulnerable then at least one of those 3 bullets will hit a vulnerable spot 88% of the time.

Last edited by Woke Up Dead; 09-24-2014 at 01:19 AM. Reason: 68% should have been 66%
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  #686  
Old 09-24-2014, 04:03 AM
Pursuivant Pursuivant is offline
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Quote:
Originally Posted by Woke Up Dead View Post
So in the end I think we agree while still thinking we're disagreeing. There might be too many incendiary bullets for 1939-1941 planes and scenarios, but by 1942 the beltings in-game start to look like like they did in the war. It would be nice if players or mission builders could pick their beltings, but that may not be so easily done.
Custom beltings is one of those things on my very long wishlist of improvements.

There was a huge amount of change in aircraft armament during WW2, as plane designers quickly realized that rifle caliber bullets weren't good enough, and even 12.7 mm/0.50 caliber guns weren't effective against big planes. For guns that were used from the first to the last day of fighting, it really makes sense to have custom beltings.

What TD could possibly do is link beltings to scenario dates, creating beltings like "0.50 BMG 1942" or "0.303 BMG 1940".


Quote:
Originally Posted by Woke Up Dead View Post
But without knowing what the modeled components look like, we can't actually tell what the bullet went through, right?
Yeah, that's the problem. Compound the problem, some radial engines are basically "just a star" with the crankcase and fuel injection systems in the center and gaps between cylinders. Other engines were twin ranks, with staggered rows of cylinders and big turbo supercharger mechanisms directly behind the cylinders and crankcase, which means that just about the entire engine is vulnerable.

But, figuring out what really happens when you punch a hole in a part of that complex mechanism really requires much more complex simulations or historical data than I can hope of doing. All we've got is the received wisdom that radial engines were tougher than inline engines, but I have no idea how much tougher they were.

All I can do is point out discrepancies between damage models where there are common elements - like the engine in the SBD being tougher than the CW-21, which is tougher than the Buffalo. Which model is right, I can't say.

I like the idea of all the planes in the game being tougher, especially against small caliber bullets, but that's my preference.

Quote:
Originally Posted by Woke Up Dead View Post
It could be that there are enough critical components modeled in and behind the engine that when you test the way you do (flying directly behind a bomber's six and eating bullets), you will consistently take critical damage.
True. I'm expecting to get shot up, and the more hits you take the more of a chance that you get a critical hit. But, for reason I described above, I'm looking for consistency across damage models, unless there's something that's clearly different about a particular plane.

For example, one of the many faults of the Buffalo MkI was that the RAF purchasing commission screwed up and ordered the plane with too small of an oil tank. That meant that the Buffalo Mk I was more prone to overheat than other marks of the Buffalo, and it would make sense that a hit to the Buffalo's oil tank would shut down the engine faster. But, the Buffalo Mk I doesn't seem quite as vulnerable to engine hits as the B-239, which by all accounts was the better, more reliable, airplane (once Brewster's trick of supplying planes with used, worn-out engines was fixed).

So, if TD feels the urge to wade through all my posts, perhaps they could stomp some more bugs. It looks like they've already got some kills to their credit, since there are some DM changes to planes like the Mustang and Spitfire forthcoming in the 4.13 patch. Go Daidalos Team!
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  #687  
Old 09-24-2014, 07:33 AM
gaunt1 gaunt1 is offline
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Quote:
All we've got is the received wisdom that radial engines were tougher than inline engines, but I have no idea how much tougher they were.
Hmmm, P-47 returning home with several shot-off cylinders? Or similar story with Fw-190? Both happened in ww2, their engines were very tough, just like other radials.

BTW, please, do some tests with La-5/7 and Yak-9U too!
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  #688  
Old 09-25-2014, 03:32 AM
Pursuivant Pursuivant is offline
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Originally Posted by gaunt1 View Post
Hmmm, P-47 returning home with several shot-off cylinders? Or similar story with Fw-190? Both happened in ww2, their engines were very tough, just like other radials.
I think you're right. IMO, all radial engines should be pretty damned tough to knock out, although the PW R-2800 was notably tough. That said, I think that they should be toughest against blown out cylinders. Bullets, especially big ones, through the crankcase should be much more effective at stopping the engine.

I think that the best way to create DM for engines is to base the amount of damage an engine can absorb on mass. Lighter engines can take less damage, larger ones can take more. The exceptions might be if you've got an engine with a radically different design which makes it more or less vulnerable to damage - like the early jet engines.

Quote:
Originally Posted by gaunt1 View Post
BTW, please, do some tests with La-5/7 and Yak-9U too!
This isn't a closed shop! You can do DM testing, too.

1) Set Arcade Mode = 1 in Conf.ini.

2) Go into QMB, choose a flight of early war bombers or attack planes with .303, .30 or 7.62 mm defensive guns as your targets, give them Ace AI and enough altitude that you can maneuver above and below them. Choose your plane and start flying.

You want Ace AI because it makes the tests go quicker, and also helps pick out bad DM modeling because the Ace AI will start hitting you at 600+ meters, when most rifle caliber bullets are going to seriously lose energy. (For example, a .30 caliber M2 ball round is going to lose about half its energy at about 400 yards.)

You want small caliber guns shooting at you to eliminate the possibility of getting hit by HE rounds or big bullets which can mess up experiments.

0.50 caliber or larger bullets do enough damage, even at range, that any hit from them is likely to be realistic in its effects, especially if it's a HE bullet.

3) Deliberately use stupid tactics like slowly overtaking the formation from 6 o'clock level.

Ideally, you're looking for hits at long range (~400+ meters), where armor plate, armor glass and even a thick plate of mild steel should be able to defeat a rifle caliber bullet.

4) Use the pause function and external view to periodically take a look at the damage you've collected. Take screenshots of any damage result that seems weird.

5) Try to keep track of how far away you were from the guns when you got hit. Some planes have unrealistically accurate gunners. That's a bug report, too.

6) Repeat 10+ times to see if you can get repeated results for the weird damage results. You're looking for "critical hits" that seem out of place - things like a very high percentage of control surface hits, loss of engine power, engine inoperable, fuel leaks, fires or pilot killed/wounded.

7) Once you've gotten a sense of the trends, and/or you get tired of being an aluminum clay pigeon/flying pinata, hop onto the internet and find a good cutaway drawing of the plane you just flew. Compare your screenshots to the drawing.

Sometimes a hits that "seem weird" turn out to be valid. For example, some planes really did have gaps between armor plates and armor glass to the pilot's front, or an oddly-shaped fuel tank in front of the pilot (e.g., F4U Corsair).

8 ) Once you've gotten a sense of the trends, start looking at similarities between planes. For example, look at how the same engine takes damage when mounted in different planes. (e.g., Alison V-1710 - immortal in the P-39/P-400/P-63, less tough in the P-38, substituted for something made of crystal and tissue paper in the P-40/Hawk 81/Tomahawk).

9) Post your results to this list and make Team Daidalos's lives harder.
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  #689  
Old 09-25-2014, 07:31 AM
gaunt1 gaunt1 is offline
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Quote:
Originally Posted by Pursuivant View Post
This isn't a closed shop! You can do DM testing, too.
6) Repeat 10+ times...
I'd do this gladly, but I lack one very very important thing: time.
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  #690  
Old 09-25-2014, 09:57 AM
Buster_Dee Buster_Dee is offline
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Gotta love those round engines. I was going to argue that crankcases (I would include nose case and rear accessory section) were not necessarily the "weaker" component. But, considering that a lot was packed into a small space, it's hard not to hit something important. On the other hand, a hole, by itself, is not like a hole in an oil pan. Dry sump oiling (and large oil tanks) are a different animal when you consider that the often-reported survival despite the loss of a "jug" was definitely a hole in the crankcase.
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