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How far does a 50. cal bullet have to fly before it impacts with no effect?

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P-40 has no wing fuel tanks,  main tank under pilot with fair amount of radio equipment between it and tail

 

Cheers, Dakpilot 

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2 hours ago, [RBRI]Khaela said:

Now the p40 is a rugged plane but I expected at least a fuel leak or something from the bredas. 

i've only flown the P-40 a bit in career, but i'm surprised how durable the engine is. Normally when i intercept bombers (JU-88s) with the classic "sit right behind them and shoot" strategy it goes south pretty quick with the MiG-3 immediately taking cooling system damage that means the engine is toast within a minute. When i did this with the P-40 the engine just tanked their tail gunner's fire. After a good bit of fire i did get a cooling system damage and a leak out the rear which stopped before i disengaged. Was able to RTB and only got engine cooling issues at landing with radiator at normal position. 

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Still some issues with Bullets and Balistics ingame Over long ranges. 

As in Even if you Dive in a massive Factory or Ship from 5K and starting Firing at 4KM up (Firing straight down) 
The bullets never reach their target even tho they would only loose about 10-15% of energy from drag and nothing from gravity as you know going straight down. 

They just randomly Vanish 
same if you try shoot AAA from much more than 1200-1300m the bullets never reach it even if you fire high. 

 

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1 hour ago, =TBAS=Sschatten14 said:

The bullets never reach their target even tho they would only loose about 10-15% of energy from drag and nothing from gravity as you know going straight down. 

 

I think drag is the main energy loss, and as long as a bullet isn't fired in an upward direction gravity won't hinder it at all, regardless of the angle. Gravity makes bullets drop, not slow.

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5 hours ago, [RBRI]Khaela said:

Did a strafing run on some ground targets in a BF110, with a mate just doing pass on the same target just a few seconds before me. Managed to put a salvo into him damaging one of his engine, all ricoches.

 

Oh so it does happen. Ok tks!

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It wouldn’t be shocking if there were some sort of artificial cap on gunfire in game.  Trying to calculate thousands of bullets falling from altitude would likely eat a lot of system resources for very little gain from an end user perspective.

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Not real bullets or ballistics were dealing with here.  How could a program possibly know the energy state, attitude, and relative motion of the object you've selected to open up on out of all the possible targets present in game?  Not happening.  I'd wager your getting a set energy volume based on your weapon type, airspeed, and distance from your muzzle, nothing more.  A jet receiving fire in a head on at 600 Kph in addition to your closure speed probably adds nothing, how could the game possibly know the specifics of what you just targeted?  All it knows is there's a bunch of calculated bullets with a certain amount of energy at X point it just made contact with.

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On 1/10/2020 at 3:13 PM, =TBAS=Sschatten14 said:

they would only loose about 10-15% of energy from drag

 

Sounds unlikely. Bullets fairly quickly start to tumble too, which would spunk away most of their energy in short order.

In fact, after 1000 yards a 50. BMG round loses 50% of its energy.

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5 hours ago, [CPT]Crunch said:

Not real bullets or ballistics were dealing with here.  How could a program possibly know the energy state, attitude, and relative motion of the object you've selected to open up on out of all the possible targets present in game? 


The program knows all those things at all times. There is nothing that happens in game that the program doesn’t know about. That’s how it generates the game world for you to interact with. Under the hood, all games are literally all numbers. What could have been a potential target or your intended target is irrelevant. All that matters is the data representing the virtual bullet and the data representing whatever game object that bullet actually intercepted in the game world.

Edited by Zirashi

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going straight down? 
think they showed that with spector firing chain gun from so high up.
either way was my point is they would not just Vanish after about 1400m . 

 

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2 hours ago, =TBAS=Sschatten14 said:

going straight down? 
think they showed that with spector firing chain gun from so high up.
either way was my point is they would not just Vanish after about 1400m . 

 

Yes because the air resistance over the first few seconds of flight is going to be much more significant than the acceleration due to gravity. If it's halved its energy in 1000 meters then the speed has reduced by around 70% so you're looking at an average deceleration of around 120ms-² which is way more than gravity's 9.81.

They probably make them disappear because they're becoming *relatively* harmless at that range

Maybe it's less likely to tumble going straight down though, but I don't think tumbling is significant at the first 1500m for a high velocity round like M2 .50

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2 hours ago, 71st_AH_Barnacles said:

Maybe it's less likely to tumble going straight down though,

Actually,  they are more likely to tumble if shot straight up than if shot at an angle, which means their terminal velocity will be higher once only gravity is moving them. At least, that's what the anti-celebritory gun firing web sites say, the higher terminal velocity causing them to be more dangerous than one simply falling.

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On 1/11/2020 at 4:35 PM, [CPT]Crunch said:

Not real bullets or ballistics were dealing with here.  How could a program possibly know the energy state, attitude, and relative motion of the object you've selected to open up on out of all the possible targets present in game?  

Here is a good video showing just how detailed a game can get with ballistics: 

 

It's worth pointing out that since that video came out in 2013, that same game got an update in 2015 changing the ballistics to even depend on the barrel length and "powder burn rates" for firearms. This allows for different performances of a single ammunition when fired from rifle vs a carbine. For anyone who knows the specifics of US military ammo: mods that add ammo can specify this correctly in their config for the ammo and you'll see M855 rounds performing poorly from an M4 over an M16A4. If you then do the same comparison with M855A1 ammo the difference is significantly less. (IL-2 has little need to do this as most weapons in game are consistent and fired the same ammo throughout WWII. A config per-weapon is good enough for sim accuracy.)

 

Now ArmA 3 has an advantage here in that the devs can neglect speed of the vehicle firing a round, and speed of the target for any calculations of energy. Despite this, it's extremely clear that they do as using a doorgun on a helo requires one to aim behind a stationary target to successfully hit it. The lag required to hit the target depends on the distance and of course the speed relative to the target. Regardless, every single round that is fired in ArmA 3 is simulated until it is no longer moving (or possibly until it exits the area that a server has loaded).

 

On 1/11/2020 at 4:35 PM, [CPT]Crunch said:

how could the game possibly know the specifics of what you just targeted?

Since IL-2 is not a hit-scan game, there is no reason the game needs to know, nor care what a player is targeting for the player to score hits. When a player fires, all the game would have to do is spawn a round with a muzzle velocity vector, and then a vector that is the aircraft's current speed and direction. Take the dot product of these two vectors and that is the velocity vector that the round takes.

 

On 1/11/2020 at 4:35 PM, [CPT]Crunch said:

All it knows is there's a bunch of calculated bullets with a certain amount of energy at X point it just made contact with.

To take the ballistics from what you suggest here and then factor in relative velocities would not be that much more work. When the program determines that a round is intersecting an object which can be "damaged" by said round, it could then takes the round's current vector with its current velocity (the vector has changed due to gravity, maybe wind but i'm not sure if the game takes that into account. while the velocity has been adjusted over flight to reduce it simulating air resistance) and compares that to the target's vector and comes up with a final impact energy. 

 

All the above is speculation about how to go about it mathematically with a program. The math of it is relatively straightforward, and only makes use of data that the sim already needs to have. Having this vs not having this would probably come down to how many more calculations per second the sim needs to do. Likewise; de-spawning rounds when they're practically ineffective is a way in which the devs could save significant calculations per second on the game. 

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Except the conditions and mechanics aren't exactly the same for each individual bullet.  No way, for an air duel at speed in motion, than multiply with others occurring concurrent.  Not buying it.

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9 hours ago, [CPT]Crunch said:

Except the conditions and mechanics aren't exactly the same for each individual bullet.  No way, for an air duel at speed in motion, than multiply with others occurring concurrent.  Not buying it.

Yet ArmA 3 manages it for tens-of-thousands of rounds at a time? If it were as intensive as you suggest then anytime someone opened up with a minigun it'd lag the game, yet it does not?

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PC tracking 10,000 bullets bouncing off 5,000 surfaces should not be that hard. 

That what Phsyx is meant for and so on, it can track thousands of water particles flowing over all sorts of obstacles ,
not that IL2 uses it

(even tho air battles would look insanely better with thousands of parts of debris all falling in wind properly) 

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On 1/10/2020 at 7:22 PM, KW_1979 said:

It wouldn’t be shocking if there were some sort of artificial cap on gunfire in game.  Trying to calculate thousands of bullets falling from altitude would likely eat a lot of system resources for very little gain from an end user perspective.


Yet this was done at least two decades ago on much, much weaker systems. WW2 online was / is an early 2000s game yet it managed to simulate the entire Bodenplatte map (May 1940 Ardennes assault) with thousands of concurrently online players, infantry, tanks, ships, aircraft. The ballistic system was top notch and calculated every single bullet and fragment, what it penetrated inside a tank, how much it slowed down or richoheted in the process, and heck how much secondary fragments it created and what those fragments did.

 

It could handle things like that a fighter diving vertically on a tank may just penetrate thinner top armor due to the added velocity of the fighters speed.

 

This demonstration below is 12 years old now.

 


The thing is not all that complex especially for modern CPUs. It is  simply a matter of developer will and resources.
 

Edited by VO101Kurfurst
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