On German ammunitions

[343KKT_Kintaro]

Hey chaps, has anyone here ever tested the power of all the different German ammunitions in IL2CoD? If so, is there a real difference found between each type of projectile? Do we have a tutorial on this?

[Guest deleted@7076]

-Deleted-

Edited September 12, 2022 by Varrattu

[OBT-Mikmak]

The weapons simulation in the game takes into account the following (source)

1) Muzzle velocity (meters per second velocity at the moment round departs muzzle)
2) Weight of the round (muzzle velocity plus round weight equals kinetic energy at the moment of impact)
3) Weight of the explosive charge (chemical or explosive energy)
4) Round metallurgic composition (ie. what the metallurgy of the round is, which translates into hardness of the metal and ability to penetrate)
5) Rate of fire
6) Dispersion (effect of vibration due to movement of the mounting during firing and flight on the accuracy of the round)
7) Gravitational effect (ie. speed at which the object falls towards the earth's center after leaving the muzzle)
8. Drag effects (rate at which the velocity of the round decays)
9) Type of explosive used in the round (ie. nitro cellulose, tnt, etc. each rated for their explosive power)

All of the game weapons are based on the real life weapons.

Forgot to mention:

10) Weight of the complete cartridge is also modeled, (in addition to the weight of the fired round) so the aircraft weight can be adjusted down as cartridges are used

11) Weapon jamming is not modeled, although no doubt it could be if we wanted, and may be incorporated in later TF mods. (the wingmount MG/FF was prone to jamming when fired in other than level flight, especially when fired in high G situations as for example, high G turns to allow deflection firing. In contrast, the Browning .303 and MG17 were not prone to jamming in these situations)

12) Round fusing... ie. how many seconds after an HE round is fired the fuse will cause the round to explode.

Edited January 28, 2021 by OBT-Mikmak

[343KKT_Kintaro]

Thank you my friends, that's very impressive indeed. I'll pay special attention to that video in Youtube. Thank you again.

[Avimimus]

Very interesting. There is no value for the size and momentum of round fragments? That would certainly be relevant for larger high explosive rounds and bombs (which, ideally, would have values for number and velocity of typical fragments, unusually large fragments, and a value for blast/over-pressure). Note: I'm not saying the modelling isn't currently great... just musing upon what would be ideal.

  

On 1/28/2021 at 1:39 PM, OBT-Mikmak said:

11) Weapon jamming is not modeled, although no doubt it could be if we wanted, and may be incorporated in later TF mods. (the wingmount MG/FF was prone to jamming when fired in other than level flight, especially when fired in high G situations as for example, high G turns to allow deflection firing. In contrast, the Browning .303 and MG17 were not prone to jamming in these situations)

 

Adding weapon jamming would be pretty neat. I think the 30mm cannon should also have some jamming issues and the early Hispano cannons?

 

I think it actually adds a lot to the game. It is rare enough to not really take away from gameplay that much. However it is also a reminder as to why autocannons took some time to replace machine-guns (as a jam on a cannon removes a lot more firepower, and as cannons were generally less reliable before 1941-1942).

 

Finally, it gives a chance to enjoy replicating historical accounts of being in a Spit V and having a cannon jam (in spite of being undamaged)... with the correspondingly greater challenge in managing  recoil 

 

Anyway - I thought it was a great feature in the Il-2 1946 mods that included it! Quite a bit of fun.

Edited January 31, 2021 by Avimimus

[Buzzsaw]

4 hours ago, Avimimus said:

Very interesting. There is no value for the size and momentum of round fragments? That would certainly be relevant for larger high explosive rounds and bombs (which, ideally, would have values for number and velocity of typical fragments, unusually large fragments, and a value for blast/over-pressure). Note: I'm not saying the modelling isn't currently great... just musing upon what would be ideal.

Yes there is.

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Kinetic damage

• When a bullet impacts a hitbox, the travel distance is calculated as:

double travel =  0.0000000010 * kineticEnergy /(projectileDiameter*projectileDiameter)/ConstructionalMaterialMultiplier;

 

 

where ConstructionalMaterialMultiplier is a value that depends on the material being traversed.

• if the bullet is hardened, (i.e. AP), the resulting travel is multiplied by 1.01, for other bullet types the travel is multiplied by 0.42.

• When you have the travel, the new kinetic energy of the bullet is calculated: kineticEnergy *= 1.0d-obstacleThickness/travel.

• And the new speed of the projectile: square root of 2.0 * kineticEnergy / projectileMass.

• At this point, if the bullet is still moving, you leave it so it can damage other hitboxes, or if you have a cavity hitbox, the same calculation is done for the exiting wall of the hitbox (the bullet can perforate the entry point but can be stopped in the exit point).

 

 

Explosion damage

 

Explosions are a complex subject, all are dependent on the  PayLoad explosive type... each explosive type has its own code.

 

There are multiple types of Explosion and Fragmentation rounds... Concussion, where the shell primarily damages with explosive force, Fragmentation, where the shell primarily causes damages by sending metal fragments through the target, and Incendiary, where the explosive force is mainly designed to spread the incendiary material around the target... which then ignite any target materials which are capable of catching fire... these fires then create secondary damage effects if allowed to burn... they can be put out with wind velocity or extinguishers.

 

Concussion damages with a shock wave which emanates from the point of explosion and whose force decays the further from the starting point... you can see this effect if you drop a bomb on an airfield and watch what happens to parked aircraft near and far to an impact.

 

• Concussion Payloads have a secondary fragmentation effect with 75% of the original shell mass.

• Fragmentation Payloads have a secondary concussion effect.
• Incendiary can generally be added to any type, with those added effects.

• For fragmentation,  shrapnel  is calculated:
  • shellMass = projectileMass - payloadMass
  • shrapnelAverageMass = 0.0002d * shellMass, then the value is clamped between 0.002 and 0.0175d
  • number of fragments = 0.5 + ( shellMass /  shrapnelAverageMass)
  • the amount of  shrapnel still active in respect to the original is recalculated if the target is at more than 5 meters from the explosion.

---

 

All bullets and fragments are tracked individually by the game's physics engine... up to their effective range, or their self destruct range.  Bullets are 'neutral' in their effect, there are no 'Blue' or 'Red' bullets, bullets damage impartially... if you are in the path of a bullet, you get hit even if a friendly fires.  (which is why chasing a vulcher over an airfield can often result in the death of the chaser... because Friendly AAA can be quite inaccurate)

 

Note:  When the term 'hitbox' is used, that does not necessarily mean a simple square box... hitboxes can be any shape or size, and are made in the shape of the object they are modeling... so for example, an oil line from the engine to oil pump or oil tank would be one long hit box which is only millimeters in diameter, but 3-4 meters long.  If hit at any point with enough power, it would leak.

 

Regarding Jamming... we are looking at possibly including it in the next module... assuming we move onto a new module.

[FTC_Karaya]

If jamming does get implemented, then please make this a separate realism toggle, so it can be disabled in online servers.

IMO this opens a whole can of worms regarding modelling. People are always quick to point out "this weapon was prone to jam, that weapon too". Besides actually qualifying these statements with sources the much harder task is to find actual data on the frequency and conditions of weapon jamming. What were the probabilities of each weapon to jam under different G loads. Maybe weapon XY only jammed if subjected to Gs and a rolling motion at the same time. All this may be interesting for singleplayer, I expect it to be a huge pita for multiplayer.

[Guest deleted@7076]

-Deleted-

Edited September 12, 2022 by Varrattu

[Avimimus]

That is brilliant information...! Thanks!

 

You guys should consider doing a few dev updates (e.g. to Steam or youtube) which cover those kinds of details... even if some of it is code that predates the original release - it is still an important part of the product/project!!

[343KKT_Kintaro]

Thank you chaps for all your messages. I'll take the time to pay close attention to all of this.