Armed Assault weapon ballistics

[frederf 0]

I think:

The bullet actually slows down but the "bulletSpeed" parameter remains constant... if that makes any sense.

[maddogx 13]

Also, the myth that ArmA bullets all travel at the same speed can definitely be proven wrong if you look at the actual measurements.

Errr...

Just to be sure : for me, the "myth" (that I found out to be true) is that ArmA bullets do not decelerate during their flight, ie their speed is constant.

Is that false? Because when I monitor a bullet's speed using a loop, I don't see the speed change. I maybe wrong, but I don't think friction is taken into account

With what command did you check the bullet's speed? With velocity?

I haven't actually checked bullets speeds yet, but I'm pretty sure that I noticed them slowing down when trying out my bulletcam script.

[UNN 0]

@Whisper

Quote[/b] ]Is that false? Because when I monitor a bullet's speed using a loop, I don't see the speed change. I maybe wrong, but I don't think friction is taken into account

That’s already been discussed in this thread, which you were also posting in.

The speed command should not be used to measure ballistics, it is clearly not designed for that task. To get a more accurate indication of the properties of a projectiles trajectory in Arma, you should measure it's velocity over a period of time.

P.S Anyone interested may also want to read "Physics for Game Developers" - by David Bourg. Published by O'Rielly. It covers other issues like the Magnus effect and variable mass.

[maddogx 13]

P.S Anyone interested may also want to read "Physics for Game Developers" - by David Bourg. Published by O'Rielly. It covers other issues like the Magnus effect and variable mass.

Sounds like something I would read in my spare time. (Seriously, I'm a physics geek ).

But I don't think things like the Magnus effect are relevant for games, not even for ArmA. There has to be a trade-off between realism and computanional requirements.

[sickboy 13]

Suggestion to the topic creator, maybe a request for thread name could be handy, or a merge with ArmA Weapons Ballistics thread? "Curious" doesn't really describe anything and if it wasn't for a link to this thread I would've never seen the discussion and results about the ballistics

I meant in all the other aspects that VBS2 has over Arma like the tracers and things.

1. BI had to Release ArmA prematurely due to money issues, thats one of the reasons why many features and tweaks have found their way into the Patches. And don't you worry, if BI continues to support ArmA for a while as they are doing now (atm it looks like it), we haven't seen the end of additional features...

2. VBS2 is a military sim, ArmA is a game. Many of the features that are developped for VBS2 are useless for the grande public and more usefull for the military. Aside from that, the budget available for VBS2 is probably a lot bigger than that of ArmA, which can keep the development in a normal pace, putting a lot and effort & care in refining and tweaking.

[UNN 0]

Quote[/b] ]Sounds like something I would read in my spare time. (Seriously, I'm a physics geek).

That’s interesting to know, I think we could definitely do with more physics geeks posting around here. This stuff does not comes easily to me, I have to spend many hours of trial and error to understand the concepts enough, to get them into the game.

Quote[/b] ]But I don't think things like the Magnus effect are relevant for games, not even for ArmA. There has to be a trade-off between realism and computanional requirements.

My point was there is more to real world physics than just the basic drag. Although the fact the book covers it suggests it's not impractical to implement in a game. At least in the guise demonstrated in the book.

But I used some basic ballistics scripts in OFP for my Mortar addon. While it’s pretty accurate over 2000m ranges using low muzzle velocities, it breaks down when it comes to increased ranges and velocities. So I assume there were other factors I was not taking into account. Since then, I have a passing interest in anything that goes beyond the usual calculations of air resistance.

[maddogx 13]

Suggestion to the topic creator, maybe a request for thread name could be handy, or a merge with ArmA Weapons Ballistics thread?

He's been banned, mate.

[sickboy 13]

Suggestion to the topic creator, maybe a request for thread name could be handy, or a merge with ArmA Weapons Ballistics thread?

He's been banned, mate.

Thanks mate, can't keep up sometimes hehe

I'll request a merge in PM to Moderators then.

[whisper 0]

@Whisper

Quote[/b] ]Is that false? Because when I monitor a bullet's speed using a loop, I don't see the speed change. I maybe wrong, but I don't think friction is taken into account

That’s already been discussed in this thread, which you were also posting in.

The speed command should not be used to measure ballistics, it is clearly not designed for that task. To get a more accurate indication of the properties of a projectiles trajectory in Arma, you should measure it's velocity over a period of time.

P.S Anyone interested may also want to read "Physics for Game Developers" - by David Bourg. Published by O'Rielly. It covers other issues like the Magnus effect and variable mass.

Hoho! I didn't check this thread further, very good news

[4 IN 1 0]

if i remember my high school physics lesson correctly, aint velocities only show that the subject straight line speed from point A to point B instead the actural air speed of the porjectial?, sorry if i say silly things but i drop it some years ago

[whisper 0]

Velocity returns a 3D vector, so the magnitude of the vector is the actual speed of the bullet (relative to earth coordinate system, wind not taken into account)

[Iron+Cross 0]

what about mass? & gravity?

Also dose any body know why the SWISS mod team were not able to make there RPG fire properly from the PZF-3 ? i noticed the replaced it after launch with a regular PG-7 instead of the Panzerfaust model & when i tried enableing the model it worked but it fired So slowly & i put the fire speed way faster yet it was so slow.. i think there is weaight points on the model or other calculations added to the models in Oxygen(2) that can be done in Oxygen

Quote[/b] ]//config ammo

class CfgAmmo {

class Default; // External class reference

class TimeBombCore; // External class reference

class MineCore; // External class reference

class BulletCore; // External class reference

class BulletBase; // External class reference

class RocketCore; //External class reference

class PZF3_HLPAT : RocketCore {

//model = "\SWM_Panzerfaust\3d\pzf3_ogive";

model = "\ca\weapons\PG7_Rocket";

hit = 700;

indirectHit = 250;

indirectHitRange = 0.3;

soundHit[] = {"\ca\Weapons\Data\Sound\explosion_large1", db33, 1};

soundFly[] = {"\ca\Weapons\Data\Sound\rocket_fly1", db-20, 1.5};

soundEngine[] = {"\ca\Weapons\Data\Sound\noise", db-50, 1};

supersonicCrackNear[] = {"\ca\Weapons\Data\Sound\supersonic_crack_close.wss", 1, 1};

supersonicCrackFar[] = {"\ca\Weapons\Data\Sound\supersonic_crack_50meters.wss", 1, 1};

maxSpeed = 864; // max speed on level road, km/h

initTime = 0;

thrustTime = 1;

thrust = 1000;

CraterEffects = "MissileCrater";

explosionEffects = "ExplosionEffects";

};

so when u replace the /ca model with the //model = "\SWM_Panzerfaust\3d\pzf3_ogive"; it dont work even when Configured, this needs more research

[kronzky 5]

Air friction (i.e. speed deceleration) is definitely implemented, and can be easily checked with a minor modification of my targetrange script.

Here's the data for a B_556x45_Ball bullet, fired from an M4:

(what I'm measuring is time over distance):

[whisper 0]

You mean speed over distance, surely?

[kronzky 5]

What's displayed in the graph is speed (vertical) over distance (horizontal).

But what I measured (how I determined the "speed") is the elapsed time at the marked intervals and put that in relation to the distance traveled (i.e. I am not using the ArmA speed command to determine speed, but I calculate it manually).

[Heavy Metal 0]

Kronzy's graph shows a 440M zero for the M4A1.

That thing should have a 200M zero.

Actually, the M4A1 (and most other guns) are zeroed in at 300m in ArmA, which matches perfectly with the data in my chart. (I'm not quite sure where you are seeing the 440 meters you mention.)

What was being talked about was  not just bullets but things like RPG's, have any of you tried to make an RPG ark properly?

That is tricky because of the unique arcs those RPGs have:

Again, I wasn't very successful in finding official ballistics charts, but the general principle of their ballistics and the range looks realistic (except that it seems to self-destruct about 100m too early, but that should be pretty irrelevant for game play);

My bad, should be 550.  Your chart shows crossover of zero at 550 meters.

***NOTE*** I AM NOT REFERENCING THE RPG CHART CAUGHT IN THE QUOTE ABOVE.*****

[whisper 0]

Kronzy's graph shows a 440M zero for the M4A1.

That thing should have a 200M zero.

My bad, should be 550. Your chart shows crossover of zero at 550 meters.

Mmmmh, zero in Kronzky chart means "ground level", if I'm not mistaken, not the crossover height. Crossover height is 1.5m

[bravo 6 0]

comon is that so hard to edit images and put the exact u.m.?

i would flunk if i showed those graphic like that.

[W0lle 1052]

Thanks mate, can't keep up sometimes hehe

I'll request a merge in PM to Moderators then.

Done

[max power 21]

Man, this thread is totally awesome. Thank you, Kronzky, for your excellent graphs. I guess we're learning that the ballistics in arma are much more complicated than we first thought. I hope this lays to rest some of the criticism regarding laserbeam m4's and simple ballistics calculations. They're much more complicated than even I thought.

Kronzky, some information on the time-to-reach-some-distance of the rpg can be found on this tradoc. It also has some guidelines on how to use the sight. It probably would be possible to extrapolate the ballistics arc from the sight information but that sounds like a lot of work.

http://www.fas.org/man/dod-101/sys/land/row/rpg-7.pdf

It mentions no sudden projectile rise.

[Second 0]

Kronzky, some information on the time-to-reach-some-distance of the rpg can be found on this tradoc. It also has some guidelines on how to use the sight. It probably would be possible to extrapolate the ballistics arc from the sight information but that sounds like a lot of work.

http://www.fas.org/man/dod-101/sys/land/row/rpg-7.pdf

It mentions no sudden projectile rise.

WOAH!

There's no better reading than one's analysis of it's cold war opponent's weapons, tactics and such... and they even can be read in internet... This is heaven

RPG-7 has quite flat trajectory (comparing to older ones). i don't know how flat, but i try to dig it from somewhere.

[Donnervogel 0]

well the ingame trajectory of the RPG and AT-4 is very flat. Kronzky's graph shows that well (just don't get confused by the scaling of the axes).

Here is a vid I made to show how flat it actually is.

[kronzky 5]

Here is a vid I made to show how flat it actually is.

Hehe... Cool!

Who needs Excel, if you can just draw a 3D-graph, real-time, right in the game!

[wex-q 0]

well the ingame trajectory of the RPG and AT-4 is very flat. Kronzky's graph shows that well (just don't get confused by the scaling of the axes).

Here is a vid I made to show how flat it actually is.

At what range were you in the video?

[Donnervogel 0]

Here is a vid I made to show how flat it actually is.

Hehe... Cool!

Who needs Excel, if you can just draw a 3D-graph, real-time, right in the game!

yes the good thing about that is too that you sometimes see things you would never have thought. Like that RPGs can deflect too like bullets It's pretty cool when you shoot t the turret of the M1 in a steep angle and it just bounces off I love arma btw

Quote[/b] ]At what range were you in the video?

it's about the length of the runway on Rahmadi. About 630m