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Q1184

Wind deflection

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q11_wind 0.65 Beta

This addon makes Arma wind influence the flight of nearly all projectiles - from GBUs to bullets and handgrenades. By default wind only influences player's projectiles, it would be unfair to influence AI's bullets, as they don't know how to handle wind deflection. However, by some requests I included the possibility to turn AI deflection on by editing q11_windcfg.hpp file.

Bullet deflection is roughly proportional to the squared distance (as it is in real life). If the wind changes during the flight of the projectile, it is reflected in its trajectory. Deflection data for small arms bullets and RPG-7 is taken from field manuals and a ballistic calculator. Deflection data for larger projectiles as well as bombs, grenades and missiles is a guesswork and subject to further tweaking. RPG rockets deflect into the wind, as they usually do due to their design. Wind deflection is noticeable at ranges higher than 300 meters with moderate to strong sidewind.

Each projectile has a wind-drift coefficient (how prone it is to drifting). The coefficients are defined in config.cpp in respective cfgAmmo classes.

To assess the wind there is an action called "Wind information" that will show you wind speed and its direction. By editing q11_windcfg.hpp you can choose between 3 variants of representation of this data:

- show crosswind speed and direction (left/right)

- show full wind speed and exact direction (degrees)

- show full wind speed and where it blows from (clock system)

You can also choose between meters per second and miles per hour as speed units.

Installation: Place the q11_wind.pbo into one of your active addon folders, place q11_windcfg.hpp into your Arma\Dta folder, start the game.

Customization: open q11_windcfg.hpp with any text editor, read the explanation, set your settings.

Note: This addon requires Extended eventhandlers addon.

Credits: Q1184

Version history:

0.1 Beta (Initial release)

0.5 Beta

- New more accurate mathematic model for bullets/shells etc

- New more accurate separate mathematic model for RPG-7

- Tweaked values, now wind drift should be closer to the real deal. SVD, M24, AK-74 bullets deflect according to respective field manuals. Their trajectory should match the real with 90-95% accuracy. 2A42 and RPG-7 data is also taken from field manuals. Other projectiles coefficients are either based on BC data or on data for aforementioned ammo (and some guesswork  :P ).

- Guided missiles are no longer affected by wind (no point in it)

- Added customizable wind info representation

- Added ability to turn on AI wind deflection

- Coefficients now stored/taken from the config, not script

0.65 Beta

- Fixed MP issues (multiple actions etc) (thx Dwarden for reporting/testing)

- Fixed zero divisor errors (thx Dwarden for reporting/testing)

- Slightly changed the structure of q11_windcfg.hpp. Please overwrite the old file in Dta folder with the new one.

- Signed. Server key available at OFPEC. Direct link: Link

- Now requires unified XEH. The issues with GMJ sight adjustment are fixed in the latest bridge addon.

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Sounds nice, I will try it.

--

You say it does not work an AI.

It's ok, but please tell me, would it be possible to make it work for ai?

If yes, that could be a nice way to affect the AI's accuracy. I'm talking about the "ak-47 sniper ai problem".

MfG Lee xmas_o.gif

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Q11 - You say snipers hell, I say real-life shooters wet-dream.

But my question is how accurate is this wind modeled. If an ArmA sniper is familiar with long distance shooting, in specifically using the science behind the art like the forumulas, will that work accurately? Half-value, quarter-value winds, etc, do they effect bullet trajector like they would in real life? In reading your description it seems like you've already done the value calculations for us...do you plan on leaving that up to the shooter in the future?

Do bullets get effected by variable wind, like variations in wind speed and direction down range?

How about other aspects of wind estimation, like flags, grass, leaves, smoke, etc? Do you have a plan to model that, or have you already?

I realize this is still an early release, but I'm very excited for it. This is something I've wanted for a long time. I do some long-range tactical shooting in real life, and know how much of a bitch the wind can be to estimate. I hope you model this in the game!

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If yes, that could be a nice way to affect the AI's accuracy. I'm talking about the "ak-47 sniper ai problem".

Whats wrong with changing the accuracy in your username.ArmAprofile file? Wouldnt that be much more effective? huh.gif

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Whats wrong with changing the accuracy in your username.ArmAprofile file? Wouldnt that be much more effective? huh.gif

It's more about the talking here:

http://www.flashpoint1985.com/cgi-bin....t=70267

But now enough "topic highjacking", sorry q1184 great job with this addon!

MfG Lee xmas_o.gif

I think the problem is that the AI will not adjust, as in they will not shoot more to the right if their bullet hits way left of me. They will again aim at me the same way they did before and hit the same spot left of me

BUT I'M NOT SURE HOW ADDAPTIVE THE AI IS

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Post a version with both Player & AI effected so everyone can see whats good or not. Both versions as a test release knowing this flaw is still worthy of a play if you wanted to share it.

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@BigDaddy5:

Yes halfwinds and stuff work properly. After all, they are just simple methods to approximate the sidewind.

Quote[/b] ]n reading your description it seems like you've already done the value calculations for us...do you plan on leaving that up to the shooter in the future?

I don't know, in Arma you cant evaluate the wind with your skin, there are no dust clouds or leaves/junk on the ground carried by the wind. I think this method is good enough as it compensates for those limitations. Also the value displayed is an approximation, and may differ from actual wind strength.

Quote[/b] ]How about other aspects of wind estimation, like flags, grass, leaves, smoke, etc?  Do you have a plan to model that, or have you already?

In Arma you can assess the wind by:

- looking at low-flying clouds

- looking at swaying grass and trees

- looking at dustclouds caused by bullet hits/explosions

- looking at smoke

- shooting downrange and seeing where the bullet lands.

Quote[/b] ]Do bullets get effected by variable wind, like variations in wind speed and direction down range?  

Yep they do, as stated in the first post. But bear in mind there's still only one global wind in Arma. It may change it's direction and speed pretty quickly though.

About wind affecting Ai's - it sure is possible, but I really doubt it's a good idea. If you still want it, just remove isPlayer check in the q11_wind.sqf. Maybe I'll post it later.

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@Q1184 - That's great, one more question...how accurately is the ambient movments modeled in ArmA? If I know what wind blows smoke at what angle, does that correctly translate to ArmA? Same with trees/grass swaying...does real life estimations of wind correctly translate to game?

I only ask this because I don't want to become dependent or reliant upon your build-in menu.

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@Q1184 - That's great, one more question...how accurately is the ambient movments modeled in ArmA?  If I know what wind blows smoke at what angle, does that correctly translate to ArmA?  Same with trees/grass swaying...does real life estimations of wind correctly translate to game?  

I only ask this because I don't want to become dependent or reliant upon your build-in menu.

Smokes may differ in how easy they are carried away by the wind depending on the particle settings their creator gave them, so it may vary depending on what effects mod you're using. The best practice i think is learning it empirically. Use DMarkwick's wind info action, included in his smoke effects. It shows the exact wind speed and direction. Just walk around with this "tool" and note what smoke/trees/grass behaviour corresponds to what wind speed. I'll see about including different types of wind info in further versions.

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So this should be MP compatible, since its client side addon?

Yeah, I think it should work alright in MP, didn't test it yet.

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Whats wrong with changing the accuracy in your username.ArmAprofile file? Wouldnt that be much more effective? huh.gif

It's more about the talking here:

http://www.flashpoint1985.com/cgi-bin....t=70267

But now enough "topic highjacking", sorry q1184 great job with this addon!

MfG Lee xmas_o.gif

There are better ways to affect AI accuracy than this.

Nice work Q11.

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This will make me blow the dust from my ArmA DVD. Sounds great, keep up the good work biggrin_o.gif

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@Q1184 - That's great, one more question...how accurately is the ambient movments modeled in ArmA? If I know what wind blows smoke at what angle, does that correctly translate to ArmA? Same with trees/grass swaying...does real life estimations of wind correctly translate to game?

I only ask this because I don't want to become dependent or reliant upon your build-in menu.

Smokes may differ in how easy they are carried away by the wind depending on the particle settings their creator gave them, so it may vary depending on what effects mod you're using. The best practice i think is learning it empirically. Use DMarkwick's wind info action, included in his smoke effects. It shows the exact wind speed and direction. Just walk around with this "tool" and note what smoke/trees/grass behaviour corresponds to what wind speed. I'll see about including different types of wind info in further versions.

I should say here that currently the wind info in the smoke effects mod shows the direction that the wind is blowing TO. You should bare this in mind if you're expecting the more meteorilogically correct FROM usage. I might change it if people think it should be the other way.

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Very nice, was hoping and waiting for something like this to come along. Great job! notworthy.gif

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I should say here that currently the wind info in the smoke effects mod shows the direction that the wind is blowing TO. You should bare this in mind if you're expecting the more meteorilogically correct FROM usage. I might change it if people think it should be the other way.

Thanks for that clarification, I'm really not concerned about that minor detail, whatever one you want to use I think is great. I'm more concerned about having it interact with the environment to allow for quick and effective wind estimation.

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oh wow...nice.   Sounds like a fantastic way of practicing "Kentucky Windage".   I remember my first time ever firing a rifle... it was in Army Basic Training on an old M16A1 and it was when we were just doing battlesight zeroing.  I didn't know that we were supposed to maintain center mass and was just naturally adjusting my fire by aiming at where I thought the rounds should hit.  The drill sgt. told me, "stop using kentucky windage, thats what your sight adjustments will be for."  It was funny because he was impressed that I actually was hitting center mass using kentucky windage and my shot groups were excellent (I went on to earn my expert badge).   But I later learned that in fact, such techniques are indeed very useful for long range shooting in windy conditions or where precise sight adjustments are not possible.  (I guess thats where the horizontal mil dots come in handy).  

At any rate, this addon sounds excellent as far as realistic training is concerned.  I'm looking forward to practicing my long range marksmanship with this addon.  

My only experience with long range shooting was with the M60 machine gun with my assistant gunner acting as my spotter watching the fall of my tracer rounds and having me adjust fire until I hit the 800 meter targets. That was fun doing that with just iron sights. smile_o.gif

Chris G.

aka-Miles Teg<GD>

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A new version with some nice features is available, see first post for details/download xmas_o.gif

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