4.12.2 de-bugging

[KG26_Alpha]

^Definately not modelled in IL2 1946 ^


All combat aircraft have their stories of survival and getting home against incredible odds,
but there's more that didn't make it home and we shouldn't want to model the aircraft to represent the "few" but the many.


Perhaps some engines need "balancing" as the damage modelling seems strange when you start to compare engine v engine hit for hit,
some were tougher than others but some seem unbreakable where others have a glass jaw.

[shelby]

here is a bug in p47d10 cockpit

[Woke Up Dead]

Bug: the P-39 has FLIR (Forward Looking Infra Red). Fly a P-39 during a night mission and turn on the cockpit light to see what I mean.

Similarly, pushing the stick forward until you start redding-out from negative G's gives all pilots a brief moment of infra-red vision.

[Pursuivant]

Originally Posted by ElAurens

The Hawk 75-4 used the Wright Cyclone R 1820 single row engine, not the P&W Wasp R-1830 twin row engine.

Hmm. I though that it was the other way around, and that the P-36 used the R-1820 and the Hawk 75-4 used the PW R-1830.

Thanks for the correction.

In my defense, I'll say that it's a pain trying to find technical details about all the various Hawk 75 models. Curtiss would sell to anyone and they'd customize just about anything but the basic airframe to make the sale. P-36, French Hawk 75, Finnish Hawk 75, Thai Hawk 75, British Mohawks, etc. It gets confusing!

[Pursuivant]

Originally Posted by KG26_Alpha

All combat aircraft have their stories of survival and getting home against incredible odds, but there's more that didn't make it home and we shouldn't want to model the aircraft to represent the "few" but the many.

Actually, I think that IL2 does a pretty good job of modeling collisions, even if the damage textures don't show it.

Since all my bad tactics in the QMB often results in the mission ending with my plane in pieces after a collision with a bomber (e.g., control cable taken out, PK or wounded, or just overtaking too fast and misjudging distance on the breakaway) I've gotten a good sense how often your plane dies due to a collision.

Usually, you die horribly, but sometimes you get away with just a dead engine or a missing tail, while the other plane breaks up (especially if you hit a wing or tail that's already shot up). But, occasionally, even after a solid hit, the other plane survives, like the Me-410 in Alpha's picture.

The main reason that it <i>seems</i> like planes do or don't survive damage or collisions as well as they should is due to the damage textures. Those are based on the artist's whim, and are more representative of what "looks cool" than the sort of damage that would really kill or damage a plane.

For example, planes like the P-40, P-47 or Corsair could get back to base after suffering wing damage equivalent to what the IL2 damage textures considered to be "destroyed."

If you're a connoisseur of bullet-shredded aluminum as I've become, that's a bit of an immersion killer, because you say, "Why can't I fly this damned thing! There's a picture in Osprey/Squadron/Mushroom/Whatever book No. X which shows a plane with the exact same damage that got back to base!"

But, once you learn to sort of overlook the damage textures and think in terms of "light," "heavy" and "destroyed" the damage modeling to the airframe and collision results make more sense.

[Pursuivant]

By request, last night I was able to test the La-5.

This is actually a good airplane to test, since it's one of the models from the original IL2 game, so the damage model is likely to be crappy. It's also Soviet, an outstanding design, it was well-liked by pilots and mechanics alike, and was one of Ivan Kozedub's favorite planes, all of which might have made the damage modelers a bit generous.

What we've got is a lightly-built mid-war plane with an excellent engine and pair of excellent cannon, but short range and some other quirks the game can't model.

In terms of mass, it's about 60% the loaded take-off weight of a P-51, 15% lighter than a Spitfire Mk V, and 20% lighter than a Fw-190A.

Targets were the usual Ace AI Wellington III squadron, this time wearing German colors. Altitude started at 5,000 meters, which didn't exactly favor the La-5.

Airframe damage absorption seems to be quite good, the the plane registering about a dozen small caliber bullet hits before the light damage textures appear on the wings or fuselage, and virtually unlimited ability to absorb damage from small caliber bullets before the heavy damage textures appear. But, I didn't get much of a chance to test this, since other types of hits took out the plane first.

If anything, airframe damage models might be too generous for such a lightly built plane, especially for early models which had the typical Soviet production problems.

Engine damage absorption also seems to be quite good. The plane can consistently take 2-3 bullets to the engine at moderate to long range (300-600 meters) without loss of power. It can absorb about half a dozen bullets at medium to short range with some loss of power, and maybe about a dozen with severe loss of power and eventual engine failure.

For a small radial engine, this is pretty good, but not quite as good as the SBD Dauntless, perhaps because the engine is twin row. In any case, it "seems right", and there are no anomalous results like the engine stopping instantly or losing massive amounts of power after just one hit at long range.

Control Hits: Like many early game DM, I think the La-5 is too vulnerable to critical hits, especially control hits.

Remember, a rifle caliber bullet basically has to intercept a control cable or bell crank to sever it, and they're not likely to tear the aluminum skin of an airplane up sufficiently that they'll jam something. Even so, in the 20 or so missions I flew, I picked up something like 4 control cable hits, mostly due to hits to the wings.

Also, while it's just a damage texture issue, the light damage texture for the wings is "burned canvas on the aileron" which seems out of place since almost all the wing damage was to the inboard wings, and none of it was to the ailerons.

Another item for the IL2 wishlist: Separate damage texture modeling for the control surfaces.

Fuel Fires: Another issue is the vulnerability of the wing tanks to fuel fires. I've worried that topic to death elsewhere, but to recap.

1) Unless it's explosive, it's the second or later bullet that starts a fuel tank fire.

2) There needs to be time between bullets to start a fire since fuel has to leak and vaporize.

3) Even Incendiary or tracer bullets can't ignite liquid gasoline.

4) Self-sealing fuel tanks prevent fuel from escaping, minimizing the chance that subsequent incendiary hits will start a fire. They work almost instantly and almost perfectly against bullets of up to 0.50 caliber (except for 0.50 caliber HE bullets).

Additionally, the La-5 had a unique system that vented exhaust gasses into the fuel tank to act as a fire extinguisher.

So, the La-5 should basically be fireproof, especially against small caliber bullets.

As it is, just 2-3 closely spaced bullet hits in a single burst was enough to start a fire in the fuel tanks. This was the main way that I died.

As another damage modeling bug, fuel fires continue long after the fuel is exhausted! But this seems to be a consistent bug for all the planes in the game. Remember: No fuel, no fire!

Gun Hits: A final damage bug seems to be a high proportion of cannon hits. In part, this is because the cannons are near the engine, and the engine is the gunner's target of choice when aiming at an incoming attacker. Even so, most of the vital parts of the guns and ammo runs were behind the engine and should be somewhat protected.

I did get a few gun hits which were quite fair, though, with the bullet going straight down the barrel!

Pilot protection: Pilot protection seems good, with a relatively low number of pilot kills or injured results. Those that occur seem fair, since the La-5 didn't have armor glass. Mostly, the very low percentage of PK results come from the very low profile cockpit. The engine absorbs most of the damage.

Typical engine damage required to get the engine to really start slowing down. The engine lost about 50% power and died about 2 minutes later:

http://forum.1cpublishing.eu/attachm...1&d=1411712499

Cannon hit, maybe a bit weird since the bullet hit runs exactly parallel to the barrel and might just miss the breach or ammo feeds (need a better 3-view to be sure):

http://forum.1cpublishing.eu/attachm...1&d=1411712499

Weird burned aileron light damage texture (note: not all damage to wing shown, the wing had previously a few more hits, but all inboard of the aileron).

http://forum.1cpublishing.eu/attachm...1&d=1411712499

[gaunt1]

Thank you for the test!!!

Seems like DM of the engine is quite correct. But airframe should be weaker in 4.14+

[KG26_Alpha]

Originally Posted by Pursuivant

Actually, But, occasionally, even after a solid hit, the other plane survives, like the Me-410 in Alpha's picture.

Seriously !!!!



PS: Im going to have to put you on spamming alert, unless you clean up your posts, and start paying attention.

[Janosch]

It appears that you can lock tailwheel on a B-25, despite it having a tricycle landing gear! With the "tailwheel" locked, takeoff becomes a challenge to say the least, and landing is very hazardous!

Yet more mirror surface bugs: the sun shines through the mirrors of all Macchi C.202 and C.205 models.

[Pursuivant]

Testing the La-5F

In terms of DM, almost the same plane as the La-5, although a bit more vulnerable to engine damage, perhaps due to the bigger and more complex engine. In a very few cases, the engine can be badly damaged by just a few small caliber bullets.

Other than that, the Shvetsov ASh-82 is one of the toughest engines in the game, perhaps even better than the P&W R-2800, an engine approximately 200 kg heavier and noted for its ruggedness.

The only DM problems are that the plane is rather vulnerable to control cable hits - especially elevator control hits.

Also, the plane is a bit too flammable, especially since it had the exhaust gas fuel blanketing system in addition to self-sealing tanks. Since the exhaust blanket system was only turned on prior to entering combat, it might be simplest and easiest to model it as a form of fire extinguisher for the fuel tanks.

Armor glass seems to work realistically, although given the narrowness of the cockpit I collected a number of pilot kill results from hits around the armor glass. That's not a DM problem, just a fault with the plane itself. The few bullets that hit the armor glass at range seem to have been stopped, the bullets that hit the armor glass at close range went right through - which might be realistic for AP bullets, maybe not so realistic for tracer or incendiary.

Edit: La-5FN DM seems identical.