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II/JG17_HerrMurf

Waist Gunning Physics

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Just curious for those who do a lot of mud moving. Do these physics work for your defense in the game? I find particularly 7:13 interesting.

 

 

Edited by II/JG17_HerrMurf
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It works for me! with the Junkers 52 gunner. 

However it is very difficult. 

Would be so much easy to learn with the aiming help option. Sadly, it is not working for gunners. Nor unlimited ammo .

Edited by TG1_Nil

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I find all the gunner positions a little flawed. but I do play in VR.

 

however, old training films always help!

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The waist guns work just as the movie says.  (Great film BTW, thanks). 

 

Take a He111 and have it flying on autolevel close to the ground. Now take a waist gun position and fire at ground targets at the side, keeping the sights on the target.  You will see the fall of shot missing the target a long way in the direction of travel of the aircraft.  Ie the bullets have the plane's initial vector added to their motion.  To hit the ground target you have to allow deflection for your own motion: so it would also be necessary for an enemy fighter with it's nose pointed at you as in the film.

 

The only thing I am not sure about is whether this initial vector is affected over time by side wind resistance, but over our engagement ranges this should not be at all significant.

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In the He-111 it works very good take a look how good it works from 2:20 to 2:40

 

 

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When firing  right or left direction from Gunner position and plane is traveling straight, you can  see how tracer s "bend" - you see it's side.  

Edited by 307_Tomcat

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It is just like that strafing from the side guns on the He111 - in fact I was struck by just how far behind you have to aim when experimenting this morning. Given that, and as Tomcat says there appears to be a little falling behind of the shots with range, suggesting that the degradation of the sideways vector due to wind resistance is modeled, the ballistics look very convincing.

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It is cool to see the ballistics so accurately modeled. It would be even cooler if the AI gunners were able to be trained to take them into account.

 

As far as I can see from some tests the gunners aim according to the predicted track of the target over ground without taking account of their own vector, so they will get deflection wrong in a variety of circumstances. This is just deduction from tests - I do not know how the formulae actually work, but you can see that He111 gunners will miss stationary ground targets by not allowing for their own plane's vector in a test in this thread.

 

More on this and similar in @SAS_Storebror thread  https://forum.il2sturmovik.com/topic/39644-gunners-ineffective-with-wind/

 

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On 9/10/2018 at 9:37 PM, Cpt_Siddy said:

Crystal ball works best imo. 

 

Waist gunner psychics > waist gunner physics.

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6 hours ago, unreasonable said:

It is cool to see the ballistics so accurately modeled

To be honest, that's just a very basic requirement for a sim, and even more basic for one that deals with a period when A2A gunnery is the only way of engagement.

 

Can you imagine how stupid it would look if projectiles didn't inherit the aircraft's velocity?

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12 minutes ago, Quinte said:

To be honest, that's just a very basic requirement for a sim, and even more basic for one that deals with a period when A2A gunnery is the only way of engagement.

 

Can you imagine how stupid it would look if projectiles didn't inherit the aircraft's velocity?

 

Actually I would bet that 99% of people would never even notice, since the ratio of aircraft speed to projectile speed is so low: maybe 10% for a bomber gunner.  It is only fairly noticeable when the guns are firing out to the side of the bomber when you have a background object against which to judge the trajectory.

 

What is a requirement for a sim, if you have this, is that the gunners know about it, which appears not to be the case. Then again I would bet that most people playing the sim who have fired from the waist gunner position (both of them ;) ) did not adjust for deflection correctly either.  

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4 minutes ago, unreasonable said:

Actually I would bet that 99% of people would never even notice

I don't think so. It would lead to a very weird shooting experience for everyone. 

For example, convergence distance would depend on speed. Or you wouldn't need to compensate for sideslip when aiming. Obviously bombs would drop straight down (lol). 

Really it's been modeled in pretty much every game trying to depict ballistics instead of hitscan.

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3 minutes ago, Quinte said:

I don't think so. It would lead to a very weird shooting experience for everyone. 

For example, convergence distance would depend on speed. Or you wouldn't need to compensate for sideslip when aiming. Obviously bombs would drop straight down (lol). 

Really it's been modeled in pretty much every game trying to depict ballistics instead of hitscan.

 

I suspect that many early fight sims "modeled ballistics" simply by having a coloured graphic coming out of the front of the plane, but that is all ancient history. Whether you find it cool or not, the real issue here is the aiming behaviour of the AI gunners, given the ballistic modelling.

 

Based on the He111 ground strafing test, it appears to me that they have not watched this movie.   

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42 minutes ago, Quinte said:

 

Can you imagine how stupid it would look if projectiles didn't inherit the aircraft's velocity?

 

We don’t have to imagine. In the original IL-2 ballistics were far simpler, being affected by neither the aircraft’s velocity nor wind speed. That’s the main reason why ground attack was so much easier in that sim: You simply had to point your crosshairs at the target, maybe account a bit for bullet drop, pull the trigger and the rounds would go there.

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8 minutes ago, Finkeren said:

 

We don’t have to imagine. In the original IL-2 ballistics were far simpler, being affected by neither the aircraft’s velocity nor wind speed. That’s the main reason why ground attack was so much easier in that sim: You simply had to point your crosshairs at the target, maybe account a bit for bullet drop, pull the trigger and the rounds would go there.

 

Il-2 FB/1946 does add shooter's velocity to the projectiles.

 

When shooting to the side Magnus effect should be very noticeable even at short ranges and bullets should start to tumble early... It didnt happen in 1946 and I dont think it happens in BoX either. Yet. Only game I know to model wind drift, air pressure and temperature effects, spin drift, Magnus, Eötvös and Coriolis is Arma 3 ACE mod.

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Yeah, that was something I was thinking about... impacts on dispersion from interaction with the wind.

 

This was sort-of modelled slightly (perhaps) in the Ar-234 in Il-2 1946... but it would be interesting to discuss what more in-depth modelling should be like.

 

The impact of the wind on moving the gun is also an interesting issue (especially as waist gun positions can't be aerodynamically counter-balanced as was often done with dorsal/ventral guns). This would interact with the movement of the body during aiming. If I recall correctly some studies showed that hand-held machine guns had about three times the dispersion as hydraulic turrets did - so that is also an issue since gimbal mounts aren't nearly as rigid.

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On 9/11/2018 at 12:50 AM, unreasonable said:

 

The only thing I am not sure about is whether this initial vector is affected over time by side wind resistance, but over our engagement ranges this should not be at all significant.

 

Yes, it does. If wind resistance was not a factor, from the gunner's perspective the tracer would fly straight out from his barrel, and never lag behind the aircraft.

 

Of course, when you shoot the bullets will start to lag behind the aircraft immediately. You have to remember, bullets are not designed to move sideways and they will have a lot more drag in the direction the plane is travelling. The faster the plane is moving, the more pronounced this effect will become, because drag increases with speed.

 

You are right in saying that it is not a significant factor at our engagement ranges, but it is still a factor.

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