Improved Artillery System

[Drongo69 117]

I have been working on an improved artillery system. My inspirations are the fantastic CoC Unified Artillery addon for OFP and BIS's awful default Arma 3 arty system. If you have never used CoC UA, it places AI artillery batteries under player control and models calling fire missions in a moderately realistic way. This means you can put an AI battery on the map and by double-clicking on your radio call up a dialog to call in fire missions. The fire missions are not just spawned shells, but are shells fired by AI assets that follow ballistic arcs from tube to impact.

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The default Mk6 mortar, 155mm howitzers and M5 MLRS are all included. User addons that use the same display name are automatically detected. The player must manually enter the target coordinates and the scripts will automatically detect the correct charge, elevation, etc. Players can select low or high angle (thought mortars can only use high), rounds to fire, call in spotting rounds to adjust fire, fire for effect or plot missions for quick responses later on. All of the default Arma rounds for each gun should work. Currently the only sheaf available is converged, though I will look into alternatives after everything else is done. I also plan to add verbal reports for shot, splash, rounds complete etc.

I plan to release this as an addon rather than a script. Currently I need help with converting my mission-level dialogs to an addon. I tried it but got a bunch of errors, so if you know your way around dialogs, please contact me. I would also appreciate people with real-world artillery experience giving input (though this will be balanced against gameplay considerations). In particular, I would like to know the correct military language used for various parts of the radio interaction (eg. "Send your mission","Shot","Splash","Rounds complete", etc). Ideally I would like to provide sound files appropriate to each faction.

After an initial release I may try my luck at white phosphorous, air-burst and chemical rounds.

[friznit2 350]

I can certainly help with Arty Target VP, though I suspect you're about go get a flurry of replies from various people who have been or still are Forward Observers (I was merely a tank commander, for my sins). I suppose the question will come down to whether you want to model primary caller to FO or FO to Gun line - the first being rather more simple but the second providing many more options.

I appreciate your desire to balance realism vs game play - that's something very close to my heart because I often feel we try to overdo the 'realism' and lose sight of what actually contributes to a good game.

Gunny has been developing a Combat Support module for ALiVE (largely based on Support Radio for A2) that already has a pretty interface, but got a bit stuck on Arty. I'm sure we could come to an arrangement if you were interested in exploring options further.

[Drongo69 117]

I'm not sure what a primary caller is, but the concept I have in mind is a human FO talking to an AI battery. In game terms the FO's side of the conversation is through dialog entries and the system responds with voice files to provide cues, feedback and immersion.

I'm really looking forward to ALiVE, I'd be happy to share my code with Gunny.

[friznit2 350]

I couldn't think of a better phrase but basically it's the chap on the front line who makes the initial request for offensive support to the Forward Observer - simple Arty Target Indication. The FO will then do his assessment, coordinate with the FCC at HQ and pass detailed instructions to the gun line. Clearly the second part has many more variables and elements and you'd need to ask one of the resident FO's here for the details. The ACE2 Arty observer module or R3F Arty, whilst very US centric, are good examples of the complexity involved at that end, whereas something like Support Radio or RUM Assets is more geared towards the sharp end of the process.

[quantenfrik 10]

very much looking forward to this, because i spent quite some hours myself to calculate the low shot angles, but never got it working. would help if i could, but i can neither code nor have i any experience. good luck

[zodd 14]

I did something (kind of) similar for A2:

http://www.armaholic.com/page.php?id=16625

V2 never ended up being released but i have it somewhere - works with multiple batteries, airburst etc.

The big thing I wanted to bring in was the requirement to actually adjust fire - First round impact from 100-200m (Mortars) to up to 600m off for NGS from memory (different rounds have different defaults; can also specify own fire unit with munition type in editor with initial round accuracy, FFE #rounds and splash radius etc).

The bit I liked about it is you have to work for your effect - it isnt just work out the grid and send the rounds dead on target. Adjusting fire is kinda redundant if first round accuracy is dead on eh...

Pretty simple, basically just:

GR for initial call - add large random offset (initial round inaccuracy) and set target point to that position

move target point L/R/U/D based on FO input

I dont have time to do it any more (at this stage anyway!) but I think it would add a lot if you worked that in too (re: argument of reality v fun; it actually adds challenge to the FO role without being super difficult - means the FO does a job instead of just being the messenger boy to the gun line)

[Drongo69 117]

I'm still working on this and have done some simple MP testing. I also figured out how to make it an addon instead of a script. It currently has voices for US, Greek English and Persian (taken from Generation Kill and edited BIS assets respectively). Adjustment is necessary at the moment without needing to introduce artificial errors, though not as much as mentioned in the post above. I have been getting my values from old WW2 info:

http://www.poeland.com/tanks/artillery/sheafs.html

It would be very easy to introduce random error if needed.

@Zodd, do you mind sharing how you did air-burst? Also, currently the only real sheaf is converged, open is faked by giving all guns in a battery greater dispersion (not a true row of impact zones). Do you know that maths to do converged and parallel sheafs?

@quantenfrik, cheers, I think arty is a pretty important part of the game, I hope this addon can go some way towards fleshing it out.

[EricJ 764]

Sounds like a cool mod, as a former US JFO I can't wait to see how this comes out.

[zodd 14]

I am referring to the accuracy of predicted v adjusted fires.

The closest thing to hard data (unclass) for you that I can find is this:

http://www.dtic.mil/dtic/tr/fulltext/u2/a221243.pdf

(Study incorporating adjusted and predicted fires accuracy)

The inaccuracy I was referring to is the first round accuracy- When you send a grid for a fire mission, the data is calculated based on all available information (charge info, met data etc) but it is only an estimation - therefore the first round can land some distance from where it was predicted - subsequent rounds will land close to the first one but the adjustment process is used to bring the rounds onto the target (ie. adjust the firing data to make up for the effect of all the unknown/unconsidered variables). That is why you fire one round, send the adjustment, fire another round... repeat until it is on target THEN fire for effect (ideally...)

Basically not too dissimilar to zeroing rifle optics - bold adjust (predicted) followed by firing rounds to get it perfect (adjusting)

eg.

http://www.hardscrabblefarm.com/vn/artillery.html

Different platforms will have different first round accuracy - eg. Mortars firing at close range will have the first round land a lot closer to the initial target grid than NGS (Naval guns) firing at longer range.

The issue I have with the arty in A3 is they always fire right on the target. Whilst individual rounds have dispersion, there is no first round inaccuracy therefore no requirement to adjust fire.

The other benefit of adjusting fire is regardless of whether it is AACFF or the FO calling it in, adjustment is still required!

WRT The sheafs you are referring to - not something I have much familiarity with - Fire mission types (point, linear etc) are all you really need to know on the ground - the arty blokes will work out the guts of the details based on the target you send so cant really help you there. (Is it something that is required for gameplay or is it something that can be done behind the scenes instead? Comes down to previous question - What is the scope you want this module to do/simulate?)

Will PM re: airburst etc.

[D.Smithy 10]

As a currently serving FST Observer I'm looking forward to seeing this mod. Any help required then please feel free to PM me and I'll help where I can if needed. I'm no good at the scripting side, but technical assistance yes as this is my job in real life.

[zodd 14]

Quick airburst demos:

Mortar airburst 10m

50-50 mission - Mortars (gnd) and Arty (airburst)

(Sound a little buggered on this one)

Check pm for info

[Drongo69 117]

Just a quick update, with Zodd's help, airburst is now incorporated. It shouldn't be too long before an initial release.

[EricJ 764]

Nice to hear, thanks for the update!

[pharoah 65]

what we actually need are proper gridlines on the default maps. The current gridsquares are wayyy too large to enable you to give accurate coordinates - I know, I've tried. The majority of artillery coordinates provided on today's battlefield are the old 6 or 8 digit grid references..even to aircraft. The current method of 'spotting' by marking the map doesn't work if they're not in your squad I believe. Calling grid references isn't hard however its probably easier to say 'need pickup at gridref 210355' or 'need artillery at 234789' or something. There's none of this 'oh but I don't see it on the map..or there's lots of marks on the map..or whatever'.

[zodd 14]

They are the same as normal topo maps - you make it more accurate by dividing each visible grid square into 10x10... if it is in the grid square 44 66, you know that 445 665 is right in the middle of it, 445 669 is middle top etc (ie. you should be able to fairly accurately (with practice) get 6 fig GR by visual alone..

That is when you are zoomed out fully and have 1km grid squares... Add to the fact when you zoom in with the mousewheel the grid squares become 6fig (100m square) instead of 4 fig, it is quite simple to get accurate 8 fig GR - 8 fig GR corresponds to a 10m square on the ground, accurate enough I reckon.

[zodd 14]

Airburst/Shrapnel preview

[D.Smithy 10]

Airburst/Shrapnel preview

Looks pretty good there. Can you adjust the height of burst?

[Drongo69 117]

The way I have things scripted, I can add the functionality for 3 or so preset burst heights. I don't know how to parse variables to an event handler. The way I am doing it now is:

_airburstEH = _tube addEventHandler ["fired",{nul = _this execVM "DrongosArtillery\Airburst\AirburstFire.sqf"}];

When I tried:

_airburstEH = _tube addEventHandler ["fired",{nul = [_this,_myVariable] execVM "DrongosArtillery\Airburst\AirburstFire.sqf"}];

it would not receive _myVariable. If anyone can help with this, it would be possible to send a custom height.

[zodd 14]

Smithy.

The standalone scripts you specify the airburst height, explosion size, shrapnel details when you call it so if you wanted to use those scripts alone for your own missions - most definitely.

It also comes with preset shrapnel options but if you are willing to get a bit maths'y you can customise the shrapnel a fair bit too.

For this mod specifically, it is up to Drongo and how he wants to implement it.

Drongo:

For the way you are running it I think you would need to use a public variable. If you wanted to set the airburst height for a specific fire unit type you might be able to have a public variable (constant) in init.sqf for each specific type?

I am assuming your AirburstFire.sqf script (or a subordinate one) checks for fire unit type and assign the EH based on which unit type it is? If so you could have the airburst height specified in init for each unit and just refer to that.

eg.

fireUnitAirburstHeight[0] = Mortar

fireUnitAirburstHeight[1] = 155mm Arty

fireUnitAirburstHeight[2] = 230mm Arty

Then in your assignment part of the script, when you determine the unit type instead of using the hardcoded value, you use the relevant array reference. As it is a mod rather than collection of scripts, you could check in the init.sqf for those values first, otherwise use the hardcoded (that way if a user wants to specify his own values, he can specify them in the init.sqf ?)

Its late and I havent had a look through how you have done it so will revisit this tomorrow if it is not applicable!

[Drongo69 117]

Circular and rectangular sheafs of sizes specified by the player are now implemented. I have also improved the UI a litte:

[quantenfrik 10]

looks really nice, can't wait to try it out!

may i ask when i can hope to do so?

[Drongo69 117]

The way things are going, probably next week.

[EricJ 764]

I'd Suggest an Up/Down field as well, even though HOB is still fixed right?

[D.Smithy 10]

What do you mean by Up/Down, EricJ?

The Phrase 'Up/Down' is used for smoke/illum rounds when you want to adjust how high the fuse will set the round off. You can have illum rounds bursting on the deck if you like (Good for suppress and mark), and smoke rounds bursting a few meters above the ground (even though there is a 2 minute build up time it does leave pretty trails. Every little helps). It depends on the situation though.

If you're talking about HE Proximity fused rounds, then there are three HoB settings: low (0.9m), medium (9m) and high (18m).

@Drongo69 - That's excellent news, mate.

[Drongo69 117]

There is now an initial error depending on the distance of the target point from the firing battery, meaning observers and adjustments are essential. The displayed coordinates and the real coordinates are now separate. Airbursts can now be set to high, medium and low (though the heights currently differ slightly from D.Smithy's values due to Arma issues).

At this point I think I have completed the core features necessary for a release, though I intend to continue to add features and fix bugs. I am now looking for testers, please PM me if interested.