4.12.2 de-bugging

[Pursuivant]

Originally Posted by Woke Up Dead

Hi Pursuivant, are you aware that those arrows from arcade mode in your screenshots represent only the direction the bullets were traveling when they hit the first solid object, and not their actual path? So if a bullet is traveling towards the pilot's head but is stopped by the armored glass, the arrow will still go through the pilot's head.

Yes. Using the arcade mode bullets is just the first step. Any screenshot that looks odd, or which results in odd damage gets compared against a 3d view of the appropriate aircraft.

So, there are plenty of cases where I've seen "arcade arrows" skewer my pilot with no ill effects because armor glass and armor are doing their job at stopping the actual bullet.

Likewise, there are plenty of screenshots I've taken where the damage subsequently makes absolute sense, such as when a bullet goes right down the barrel of a gun and IL2 records it as a gun hit.

Where it's appropriate, I call out good DM work as well as bad.

Originally Posted by Woke Up Dead

Also, 2-5 bullets to reduce power or completely kill an engine does not sound unrealistic. Neither do kills from "a few" bullets to unprotected fuel tanks.

Radial engines were noted for being able to take damage and still keep running, so it seems odd that the Buffalo series has engines that are as fragile as those of an inline engine plane such as a Spitfire or Bf-109.

Here's the problem with IL2 and engine hits.

First, there doesn't seem to be any consistency as to how damage to a particular engine is modeled. For example, damage to a Wright-Cyclone R-1820 engine mounted on a C-47 might make it behave differently than the same damage to the same engine mounted on a P-36, SBD, FM-2 or B-239.

My guess is that the creators of the B-239 DM assumed that the R-1820 wasn't a durable engine, since the Finns reported trouble with oil leaks and other problems with the used engines supplied with their planes. Since the engine didn't change for the F2A or Buffalo Mk I, whoever did the DM for those models just used the engine DM for the B-239.

The problem is that there's plenty of evidence that, apart from overheating problems, the R-1820 was a very good engine.

Second, many DM seem to just model the engine as a homogenous block, and fail to distinguish between empty space between cylinders in a radial engine, hits to the crankcase (potentially quite devastating), hits to cylinder cooling vanes (trivial damage) and hits to cylinders (damaging, but not immediately lethal).

While realistic engine damage models are probably beyond IL2's limits, the model could be tweaked a bit so that bullets that don't actually hit the engine don't damage it, and so that bullets which hit near the same place on the engine don't do any extra damage. After all, you can only destroy the same cylinder once!

Third, the bullets that are consistently killing the Wright Cyclone R-1820 engine on the Buffalo series are 0.30 caliber bullets being fired from anywhere from 50-300 meters distance, and they cause near instant engine-stoppage or serious power loss, regardless of where they hit. We're talking about bullets that make small holes and which might not have much power on them when they hit.


The problem with fuel tank hits in IL2 is that I don't think that the DM takes into account fire suppression measures, all bullets are treated as being incendiary, and self-sealing tanks aren't always well modeled. (There are a few planes where the self-sealing tanks actually work, though.)

Realistically, perhaps 1 in 5 or 10 bullets is going to be tracer, incendiary, explosive, API, or similar. The bulk of the bullets are going going to be plain ball ammo. That means that you basically only have a 1 in 5 or 1 in 10 chance of getting a hit with a bullet that has a chance to start a fire.

Next, the first bullet to go through a container of gasoline isn't likely to start a fire, since it's going through liquid (or possibly through a blanket of cold exhaust gasses protecting the empty space in the tank). That bullet is likely to create a spray of gasoline vapor, which might ignite if the bullet is explosive or incendiary, but a ball bullet on its own is just going to set things up for a subsequent bullet (or a spark, or heat from an engine) to start a fire.

Multiple ball bullet hits are most likely to further shred the fuel tank and splash the fuel around, rather than starting fires.

Third, fires start instantly and automatically appear at full size. In most cases, this is just cosmetic since IL2 does a really bad job of modeling fire damage to airframes, but fire size makes a difference when determining damage to the pilot and risk of explosion.

Realistically, what might happen is that a bullet hit to a fuel tank splashes fuel around and creates pools of uncontained gasoline that get vaporized by contact with the wind blowing through the bullet holes in the airframe.

A second bullet with explosive or incendiary qualities hits and ignites the vapor. The fire spreads more or less quickly to involve all the vapor (possibly creating an explosion if there's a lot of oxygenated vapor in a small place), then starts volatilizing and burning the remaining liquid. Fuel in the tank won't have that much oxygen to burn it, but spilled fuel is likely to burn quickly.

So, you'll get small fire to start with (sometimes well modeled by black smoke in the game) that burns the spilled fuel, followed by a big "fully involved" fire that starts to volatilize fuel stored in the tank.

Originally Posted by Woke Up Dead

Finally, the only effect of light damage on the fuselage is a small aerodynamic penalty. Again, it does not seem like an unrealistic result of taking eight or nine .50 caliber bullets like the Val in your screenshot.

True. Because of the way that IL2 "paints" light and heavy damage textures you have to ignore the appearance of the damage textures vs. their actual effect.

But, the hole made by a 0.50 caliber bullet in aluminum is going to be the thickness of a man's thumb. Exit holes are perhaps going to be a bit bigger, as might holes made if the bullet enters at an oblique angle or tumbles after impact (although bullet tumbling or fragmentation is unusual for the 0.50 BMG round).

Like you said, that's going to cause drag. My point, however, is that 8-9 bullets shouldn't be enough to cause much more than drag, like making the airframe fail under stress.

Since damage modeling is an art, it seems to me that IL2's developers have made planes that were notably vulnerable in combat for any reason excessively vulnerable to any sort of damage.

That means that planes like the TBD and D3A1, which were mostly vulnerable because they were slow and didn't have good armor and fuel protection, are potentially too vulnerable to airframe damage.