ArmA III Ballistics Overhaul

[ruthberg 7]

Whether you have to use ASM or ICAO in the ballistic solver depends solely on the ballistic coefficient you use.

[Spartan0536 189]

Whether you have to use ASM or ICAO in the ballistic solver depends solely on the ballistic coefficient you use.

Metric uses a different pressure still in Hg than ICAO, this has a "significant" change to ArmA calculated ballistics alone, not to mention Metric uses 78% relative humidity where as ICAO uses 0%, for how its transferred to BIS code makes quite a difference to me. In fact changing the Baro pressure from 29.92 to 29.52 has little effect in short range shots (300m and under), however once the range extends further and further such as 1000m it becomes more and more pronounced. However in terms of REAL variable change its minimal, I mean its enough that you need to compensate for these variables as a long range sniper shooting out at 1500m+.In terms of making ArmA ballistics work as true as possible I need every % correct than I can get, with your mod its different, you get to completely simulate atmospheric conditions, I have to research the round accurately, calculate where needed, test against "reports", plug variables into a real ballistics calculator like JBM, use JBM's ballistics data table from the variables, then make the AirFriction values properly match the rounds performance. So what might be miniscule in your mod is exaggerated in my work as 5% off means a great deal and can adversely affect gameplay.

[regiregi22 32]

While I assume Spartan collaboration with ACE3 is aimed towards vanilla weapons, is it expected any near time RHS integration?

Great job you're doing here, guys.

[ruthberg 7]

I think we're talking at cross purposes. I'm trying to say that:

If you input bad data into any ballistic solver you will obviously get bad data out.

JBM Ballistics for example requires manually entered BCs to be for the ICAO atmosphere.

If you don't respect that you'll get bad "reference data" for later conversion steps.

---------- Post added at 09:26 ---------- Previous post was at 09:21 ----------

Here are a few examples of how well you can approximate the G1 drag model with airFriction:

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[Spartan0536 189]

Oh for my testing I am using my M855A1 EPR data which is 100% ON THE DOT, its backed by US Military members who helped me get the data, including some nice people from ATK. My data on the M855A1 EPR is FLAWLESS, and I do not get to say that very often, I am that confident in my data. So it only makes sense to use that as a test platform, from here its all about external ballistics and the environmental variables that follow suit, this is where I am stuck.

[ruthberg 7]

It is impossible to find airFriction values that produce a 100% error-free trajectory. We can only try to minimize the error at a certain interval.

Examples - M8851 (G1 BC of .307):

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Exact airFriction at different velocities.

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G1 drag function (green line) compared to the Armas drag function (blue- and red line).

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Drop difference between the true trajectory and various airFrictions.

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Velocity difference between the true performance and various airFrictions.

[quickdagger 170]

Ruthberg, I was not speaking about in ArmA's engine but in using an external ballistics calculator like JBM Ballistics or Hornady Ballistics Calculator

JBM danger space is wrong. Judging by its numbers at 800 m bullets will hit targets at less than one or two degrees if I remember right.

Why don´t you use Brian Litz Point Mass ballistic sover instead or GNU Ballistics, which is free for Windows?

[Spartan0536 189]

JBM danger space is wrong. Judging by its numbers at 800 m bullets will hit targets at less than one or two degrees if I remember right.

Why don´t you use Brian Litz Point Mass ballistic sover instead or GNU Ballistics, which is free for Windows?

I will look into that, I have even considered purchasing Sierra Bullets ballistics calculator which is supposed to be what is used by Olympic shooters.

[ruthberg 7]

JBM danger space is wrong.

No, it is not wrong.

Danger space is the space between the muzzle of the weapon and the target where the trajectory does not rise above 1.8 meters (the average height of a standing Soldier) ...

References:

http://www.thefrontiersmen.org/pdf/Field%20Manuals/FM%203/FM_3-21.8_g.pdf

http://www.marines.mil/Portals/59/Publications/MCWP%203-11.2%20Marine%20Rifle%20Squad.pdf

[Spartan0536 189]

No, it is not wrong.

References:

http://www.thefrontiersmen.org/pdf/Field%20Manuals/FM%203/FM_3-21.8_g.pdf

http://www.marines.mil/Portals/59/Publications/MCWP%203-11.2%20Marine%20Rifle%20Squad.pdf

Ruthberg, I have been using JBM, I have trusted them, and they seem accurate, have your findings been the same when the data points are "on target", or would you suggest a different calculator?

[regiregi22 32]

While I assume Spartan collaboration with ACE3 is aimed towards vanilla weapons, is it expected any near time RHS integration?

Great job you're doing here, guys.

Any answer regarding this? :)

[quickdagger 170]

I think JBM danger space values are unrealistic.

They say danger space goes from 965 m to 1032 m at 1000 m, or 35 m in front of the target.

Doing the math for a 30 cm vital area (15 cm radius), it would be like saying bullets strike targets at 1000 m at less than 1° of inclination.

Strange isn´t it?

tan α = 0,15 / 35

α = les than 1°

http://s28.postimg.org/jsykx9q1p/JBM.jpg (142 kB)

Hey sorry, I have not answered your question Ruthberg

I also study ballistics as an engineering hobby, and I try to change game ballistics to reflect real life. I understand there are 2 ways of improving the game behavior. One is to make better combinations of gravity and airfriction and let it use BI´s hardcoded ballistics, which should keep FPS high. And, another way is what you are already doing by scripting new ballistics.

In both cases I make in game tests just to make sure what people say around the forums really happens as they say.

:D

Edited May 25, 2015 by QuickDagger

[Spartan0536 189]

Any answer regarding this? :)

It would be up to the RHS team if they intend to use my ballistics code, Ruthbergs code, or ACE 3 code. The only stipulation I have to any developer using my code is that I am listed in the credits where my credit is due.

[ruthberg 7]

Ruthberg, I have been using JBM, I have trusted them, and they seem accurate, have your findings been the same when the data points are "on target", or would you suggest a different calculator?

JBM Ballistics is about as good as it gets.

[ruthberg 7]

I am not sure how many guns you can alias with different velocities with different rounds but if it simplifies the code I am all for it.

That depends solely on the amount of error we are going to accept. Which is something we should discuss before we start working on the magazine classes. Edited May 25, 2015 by Ruthberg

[regiregi22 32]

It would be up to the RHS team if they intend to use my ballistics code, Ruthbergs code, or ACE 3 code. The only stipulation I have to any developer using my code is that I am listed in the credits where my credit is due.

Thanks, Ruthberg. Then I ask this question for anybody, does it mean CURRENTLY RHS doesn't use those values or even plan to?

Thanks

[ruthberg 7]

That's a question you should probably ask in the RHS thread: http://forums.bistudio.com/showthread.php?184842-RHS-Escalation-%28AFRF-and-USAF%29-Release-0-3-7-%28UPDATED%29

[Spartan0536 189]

Birthday Fun Time!

Hello ArmA community, another one of my Birthday's has come and gone, and since I live in a part of the United States that is not communist I get to have some fun and learn a bit at the same time. I get to translate this into game code over time as I have actual experience in areas many people only get to see on the internet/games/movies. So I present to you my 29th birthday "tactical shootout".

IMI Uzi Unsuppressed: https://www.facebook.com/john.godfrey.526/videos/10207371214021739/?l=3888433063190956551

IMI Uzi Suppressed (Coastal Guns Uzi Suppressor): https://www.facebook.com/john.godfrey.526/videos/10207371279663380/?l=4234938779723467454

Sig Sauer P227 Tactical .45 Unsuppressed: https://www.facebook.com/john.godfrey.526/videos/10207371531029664/?l=5066980080012590731

Sig Sauer P227 Tactical .45 Suppressed (AAC Ti-Rant .45 Suppressor): https://www.facebook.com/john.godfrey.526/videos/10207371635472275/?l=59949171056496033

A few things to note here....

1. All ammunition used here was FMJ Ball spec ammo, all supersonic except for the .45 which by default is subsonic unless +P+ loaded (NEVER use +P or +P+ ammo in suppressors).

2. Even with titanium suppressors there is added felt weight to the front, this is NOT a bad thing, especially with the Ti-Rant .45, it actually mitigates felt recoil by about 25-30%, this needs to be translated into ArmA III somehow.

3. While this is an outdoor range, there is significant reverberation due to the metal overhang, this distorts the gun shot sounds.

4. If you are going with a suppressed sidearm, I HIGHLY suggest going with a .45 ACP, the bullet is designed for subsonic use, and its got the energy behind it to do some nasty damage.

5. While not shown in the videos the suppressors do add a small bit of additional velocity to the projectile, it averages about 2-3% more, its small but its there. In the case of INTEGRAL suppressors they actually DECREASE the velocity by about 5-8%. Sadly I did not get any video of the integral suppressed automatic Ruger 10-22, perhaps another time.