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fridaycat
02-15-2004, 09:05 AM
I'm interested in learning how ballistics are modelled in the game.

This would include muzzle velocity for the various gun and cannon types, assumed ballistic coefficient or drag coefficient, vertical distance between the gunsight and the gun, and any other data.

This information would make the implications of convergence distance much more transparent.

Thanks,
Dan

fridaycat
02-15-2004, 09:05 AM
I'm interested in learning how ballistics are modelled in the game.

This would include muzzle velocity for the various gun and cannon types, assumed ballistic coefficient or drag coefficient, vertical distance between the gunsight and the gun, and any other data.

This information would make the implications of convergence distance much more transparent.

Thanks,
Dan

02-15-2004, 05:51 PM
MOST of the guns are modelled with realistic drag and bullet drop. Unfortunately, some guns fire "laser beams" that continue out to infinity without any drop.

In particular, the 12.7mm Berezin and Browning quad-fifty AAA are screwed up. Most of the other guns seem to be pretty realistic. Even the artillery shells travel along a noticeable arc http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

fridaycat
02-19-2004, 10:41 PM
Can the actual data be obtained? Has it been provided? For example, what's the modelled muzzle velocity and drag coefficient for the .50 BMG?, the Mk108?, the Airacobra's 37mm, the Shvak 20mm?

02-19-2004, 11:19 PM
- Can the actual data be obtained?

Yes. It's all well documented by the manufacturers themselves, historians, enthusiasts, military records, etc.

- Has it been provided?

Yes. Else how did they get the data spot-on for most of the guns?

- For example, what's the modelled muzzle velocity and drag coefficient for the .50 BMG?, the Mk108?, the Airacobra's 37mm, the Shvak 20mm?

Search. The information is everywhere. The only guns that I know of that aren't right are the 12.7mm Berezin and the ground based quad-fifty, as mounted on the M16 halftrack. Everything else has a reasonable trajectory.

WWMaxGunz
02-20-2004, 01:12 AM
Oleg has posted a table of muzzle velocities and bullet/shell masses as well as explosive equivalents to TNT and ammo mix for every gun and ammo in IL2. I'd put it here but there is no paste function in the new forum reply to dialogue. I don't have it on my homepage so I'm not linking it here either. I'm hoping an updated version comes out with rates of fire used in the game as well.

Have fun searching, I only have ever found things by search here in the past with a lot of luck. maybe someone will post it and leave a link here or actually type the whole thing. Whoever made the forum software hasn't bothered finding much out about how forum software gets used.


Neal

VW-IceFire
02-20-2004, 12:42 PM
Here's one site that has quite a bit of gun information. There are others of course.

http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-pe.html

Here's a quote about the Berezin UB:

"Again, the Soviet Berezin UB was probably the best gun, with a ballistic performance similar to that of the Browning gun, but a considerably higher rate of fire. The UBK was the version for installations in aircraft wings. The synchronized UBS for cowling gun installations had a lower rate of fire, though a still creditable 800 rpm. This was significant, for most Soviet fighters had their guns on the engine cowling."

I don't think were far off...the gun just doesn't drop much.

http://home.cogeco.ca/~cczerneda/sigs/temp_sig1.jpg
The New IL2 Database is Coming Soon!

Oleg_Maddox
02-20-2004, 01:06 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by fridaycat:
I'm interested in learning how ballistics are modelled in the game.

This would include muzzle velocity for the various gun and cannon types, assumed ballistic coefficient or drag coefficient, vertical distance between the gunsight and the gun, and any other data.

This information would make the implications of convergence distance much more transparent.

Thanks,
Dan<HR></BLOCKQUOTE>

All that you listed and plus aerodynamics coefficients of each bulled and shell or rocket. For rockets also claculated real trust of engines and time of their work.
And when you tune the distance of fire point there are all movements of gunsight reticle, position of head and ballistic in that pont of crossed lines of bullets flight are adjested.

In BoB probably it will be visible in real time on the ground fire ajustment stand. But in FB it is all done in code.

fridaycat
02-20-2004, 01:37 PM
I haven't made myself clear. I know the historical technical data is available and can easily be googled. What I'm curious about is the specific data used by the ballistic model in the game. Is this sort of information freely talked about?

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by cosmokart:
- Can the actual data be obtained?

Yes. It's all well documented by the manufacturers themselves, historians, enthusiasts, military records, etc.

- Has it been provided?

Yes. Else how did they get the data spot-on for most of the guns?

- For example, what's the modelled muzzle velocity and drag coefficient for the .50 BMG?, the Mk108?, the Airacobra's 37mm, the Shvak 20mm?

Search. The information is everywhere. The only guns that I know of that aren't right are the 12.7mm Berezin and the ground based quad-fifty, as mounted on the M16 halftrack. Everything else has a reasonable trajectory.<HR></BLOCKQUOTE>

clint-ruin
02-20-2004, 02:31 PM
http://mitglied.lycos.de/jaytdee/fbg/weapons.html

^ JtD's excellent in-game tests.

http://forums.ubi.com/eve/forums?a=tpc&s=400102&f=23110283&m=26610215&r=26610215#26610215

Link to original IL-2 datafiles on ammunition types.

http://home.iprimus.com.au/djgwen/fb/leninkoba.jpg

WWMaxGunz
02-20-2004, 03:21 PM
Thankyou for that 2nd link Clint. Perhaps if fridaycat won't read what people post (why else ask if these things aren't discussed? it's been discussed in 100's of posts!) then maybe Fridaycat can at least look there.

It does no real good just to get the historic numbers if all that's gonna do is spark near baseless arguments from apples and oranges screenshots or "I got hit and shouldn't have!" posts. Does anyone remember the long range camera views of parked planes showing how far apart the bursts were and lack of bullet drop for VVS planes? -- Luthier I think it was pointed out from the height and size of the background trees that the comparison planes were at 2 very greatly differing distances from the camera point, ie the screenshots were RIGGED and the whole "proof" was total BS. So can we now expect Yet Another Round of Whining Disguised as Bug Reports?


Neal

clint-ruin
02-20-2004, 04:51 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by WWMaxGunz:
Thankyou for that 2nd link Clint. Perhaps if fridaycat won't read what people post (why else ask if these things aren't discussed? it's been discussed in 100's of posts!) then maybe Fridaycat can at least look there.

It does no real good just to get the historic numbers if all that's gonna do is spark near baseless arguments from apples and oranges screenshots or "I got hit and shouldn't have!" posts. Does anyone remember the long range camera views of parked planes showing how far apart the bursts were and lack of bullet drop for VVS planes? -- Luthier I think it was pointed out from the height and size of the background trees that the comparison planes were at 2 very greatly differing distances from the camera point, ie the screenshots were RIGGED and the whole "proof" was total BS. So can we now expect Yet Another Round of Whining Disguised as Bug Reports?


Neal<HR></BLOCKQUOTE>

Alteration of evidence is one thing that drives me completely up the wall and I'm glad it seems to happen less frequently of late. I am somewhat amazed that people would consider doing such a thing over a computer game, but that's people for you I guess.

I don't think there was anything wrong with Fridaycats question by itself. I would much rather have people ask a question that has been answered than have people posting ignorantly/arrogantly without knowing what they're talking about. Not that anyone would ever dream of doing such a thing around here .. :&gt;

Re: the UBK/UBT/UBS in the game, I think the problem was identified as a) minimal gravity drop effects over distance, b) no measurable speed loss - the round seems to do the same damage hitting at 1Km as it does at 5m from my testing, and I think JtDs went into that too. The gun itself is widely regarded as WW2s best quality aircraft mounted MG, so I don't see any problem with it being as powerful as it is when it hits. It's just the long range drop/damage issues that give people concern and lead to some of the more hysterical posts about the gun.

As JtD says on his test site, the thing that stands out when you go about testing the Il2/FB guns is how 'right' it seems to be rather than how 'wrong' it is. Maddox did a pretty damn good job, all things considered.

http://home.iprimus.com.au/djgwen/fb/leninkoba.jpg

VW-IceFire
02-20-2004, 04:53 PM
I doubt Oleg is going to just present us the code. Alot of it is undoubtedly inhouse stuff that they want to keep out of public domain....trade secrets and whatnot. Most game designers do exactly the same thing.

FB is supposed to approximate the real life equivalents (emphasis on approximate) so look there for what should be....most of the time I see things as working out very nicely with the comparison between game and the recorded stats.

http://home.cogeco.ca/~cczerneda/sigs/temp_sig1.jpg
The New IL2 Database is Coming Soon!

02-20-2004, 06:35 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by VW-IceFire:
Here's one site that has quite a bit of gun information. There are others of course.

http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-pe.html

Here's a quote about the Berezin UB:

"Again, the Soviet Berezin UB was probably the best gun, with a ballistic performance similar to that of the Browning gun, but a considerably higher rate of fire. The UBK was the version for installations in aircraft wings. The synchronized UBS for cowling gun installations had a lower rate of fire, though a still creditable 800 rpm. This was significant, for most Soviet fighters had their guns on the engine cowling."

I don't think were far off...the gun just doesn't drop much.

http://home.cogeco.ca/~cczerneda/sigs/temp_sig1.jpg
The New IL2 Database is Coming Soon!<HR></BLOCKQUOTE>

The Berezin's ballistics are find out to about 800-1000m. The problem is that the bullets KEEP GOING after 1000m without any more drop or deceleration.

It's as if the bullet trajectory stops being simulated around 1000m and from that point on, the bullets just coast onwards forever in a straight line without losing any speed.

Set up some balloons in the FMB and go after them in a MiG-3_2xUB. You can take out balloons at ranges of 2-3 kilometers easily.

02-20-2004, 06:35 PM
*fine. not find.

fridaycat
02-20-2004, 09:32 PM
Thanks Clint! Great information.

VW-IceFire
02-20-2004, 10:05 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by cosmokart:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by VW-IceFire:
Here's one site that has quite a bit of gun information. There are others of course.

http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-pe.html

Here's a quote about the Berezin UB:

"Again, the Soviet Berezin UB was probably the best gun, with a ballistic performance similar to that of the Browning gun, but a considerably higher rate of fire. The UBK was the version for installations in aircraft wings. The synchronized UBS for cowling gun installations had a lower rate of fire, though a still creditable 800 rpm. This was significant, for most Soviet fighters had their guns on the engine cowling."

I don't think were far off...the gun just doesn't drop much.

http://home.cogeco.ca/~cczerneda/sigs/temp_sig1.jpg
The New IL2 Database is Coming Soon!<HR></BLOCKQUOTE>

The Berezin's ballistics are find out to about 800-1000m. The problem is that the bullets KEEP GOING after 1000m without any more drop or deceleration.

It's as if the bullet trajectory stops being simulated around 1000m and from that point on, the bullets just coast onwards forever in a straight line without losing any speed.

Set up some balloons in the FMB and go after them in a MiG-3_2xUB. You can take out balloons at ranges of 2-3 kilometers easily.<HR></BLOCKQUOTE>
No I know....thats what I said http://ubbxforums.ubi.com/infopop/emoticons/icon_biggrin.gif

Fine except for drop.

http://home.cogeco.ca/~cczerneda/sigs/temp_sig1.jpg
The New IL2 Database is Coming Soon!

02-21-2004, 02:39 AM
http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif Right. After 1000 meters those 12.7mm bullets should be dropping like stones. The trajectory inside 1000m is OK, but for some bizarre reason the physics model just quits at about 1000m, then the bullets continue straight on forever and ever and ever and ever and ever and ever......