What ballistics standard does arma use in its calculations?

[Sycholic 6]

This is mainly for the developers or anyone who actually knows for fact the inner workings of arma physics....

 

Which model is arma using for calculating ballistic calculations for bullet flight?  ASM or ICAO?  I see people making mods trying to give 'realism' and they using apparently two different standards according to the ammo data given.Vanilla says ICAO (g7) but also ASM (G1)   I just want to make sure that arma can tell the difference.

[da12thMonkey 1943]

AFAIK it doesn't really use either in the vanilla game, as the ballistic simulation is not based on real world physics.
 

Quote

 

Bullet simulation is not kinematic (trajectory based), but dynamic (force based). Two basic forces are considered - drag (air friction) and gravity.

Vector3 accel=_speed*(_speed.Size()*_airFriction); // add gravity accel[1]-= _coefGravity * G_CONST;

 

https://community.bistudio.com/wiki/Weapons_settings

 

So "airFriction" is a force constant (f = a / v², where a is acceleration along the vector of the bullet, so -ve in most cases). To my understanding the devs just look at doppler data and adjust airfriction parameter find a best fit to the velocity curve over time.

[Sycholic 6]

Interesting.  Im guessing then the mods added this I'll have to ask there then since one of them is dependent on the other.   thanks for the info I wasnt sure how indepth arma was with physics calculations with projectile flights.  thanks for the info.

[Dedmen 2588]

18 hours ago, Sycholic said:

This is mainly for the developers or anyone who actually knows for fact the inner workings of arma physics....

I actually have all the formulas Arma ballistics uses somewhere. I posted them on the forums too. But going through all my posts to find them would be too much work :D

 

 

15 hours ago, Sycholic said:

Im guessing then the mods added this

There is ACE Mod's Advanced ballistics. Which uses real ballistics.

 

18 hours ago, Sycholic said:

I see people making mods trying to give 'realism' and they using apparently two different standards according to the ammo data given.

Which mods?


ACE can do ASM/ICAO which is configured specifically for each Ammo type. They usually use the one they can get data for.

See https://github.com/acemod/ACE3/blob/master/optionals/compat_rhs_usf3/CfgAmmo.hpp for example. It has all the RHS mod's ammo types and specifies which Atmospheric model the ammo uses.

ACE supports everything from G1 to G8. But so far I have only seen G1 and G7 being used.

 

 

17 hours ago, da12thMonkey said:

To my understanding the devs just look at doppler data and adjust airfriction parameter find a best fit to the velocity curve over time.

They apparently aren't doing that. Ruthberg the main Author of the ACE Advanced Ballistics stuff made scripts to generate a realistic airFriction that fit's the real bullet behaviour as good as possible. And many of them are very different from the BI ones.

https://github.com/acemod/ACE3/blob/master/addons/ballistics/CfgAmmo.hpp

[Sycholic 6]

yeah I just wanted to make sure this wasnt something that happened in vanilla but typically wasnt publicly accessable.  thanks for all the info.