Air Resistance Constant

[billee]

Does anyone here know how to calculate an appropriate AirResistanceConstant value as used in .prj files?

As it stands I think I'm going to have to make a guess, fire off a few rounds, watch the trajectory and adjust the values accordingly.

[Matt03]

That is probably the best thing to do but there may be some people around here who can help you out.

[nobluaqui]

I don't know if this will help for GR or not, but here goes:

Air Resistance= Drag Coefficient * (1/2) * Air Density * ((Relative Velocity of the bullet)^2) * Projected Area of the bullet)

Any changes in the environment affect air resistance, so all lower level physics classes leave drag out. I took some higher level courses though, so I had some fun with air resistance. "

It would probably just be easier to test the numbers in game, and then adjust them as needed.

[billee]

Thanks nobluaqui

I've used http://www.eskimo.com/~jbm/ for most of my weapons ballistics before and they've got a drag calculator so I'll give that a try in combination with your formula. I'n not too sure about the Relative Velocity of the bullet though - relative to what?

I generally prefer a mathematical backing for the numbers I put in the files. It's important I get this fairly accurate. As an experiment I'll be modifying some of the basic weapons in GR to file projectiles based upon the real world ballistics of their ammunition. At the ranges commonly used in GR I doubt the bullet trajectory will have a major impact but it may have an impact at longer distances (particularly for some of the tango weapons). I'm also thinking that just this minor difference may affect gameplay enough to make something interesting happen. I'm curious to see if the AI will be able to compensate for their weapons trajectory or if they'll blaze away assuming the current straight line path. I am also wondering if it will have an impact on the effectiveness of suppressive fire.

Of course, the chances are that this variable is ignored and everything works off the other numbers...

[Mamon]

Thing is in GR, rarely are firefights beyond the 100-120m range, except when you increase the .map range.

[billee]

I know.

I honestly don't expect there to be much of a difference in accuracy given the very short ranges in common usage. I'm just curious to see what the AI makes of it all.

[nobluaqui]

That would be relative to the air in this case, so subtract the air's velocity from the bullet's and square it. In this case, you should probably just use the bullet's velocity, and assume a velocity of zero for the air. This formula is for drag through all types of 'fluids,' including air.

[Scarecrow]

I had just wraped up a mod for myself and a few friends and the core of it was realistic and accurate ballistics- it does not seem to have much affect on AI, however it has some minor but important effects on the gameplay.

it definatly makes it more flexible but not necessarily easier, and suppressed weapons are much weaker and less accurate than their unsuppressed counterparts, adn there is a noticeable enough difference between the m-16 and the m4, though both retain usable lethality

I had also adjusted the spread and return values based on my own experience with afew of the weapons and found the results to be more to my liking, and I am not a highly trained special forces soldier, but even I can turn a corner and shoot

here's a hint for adjusting return values for a deeper sens e of realism and flow-

I based my settings on the optics of the gun, as well as muzzle lift and weight/balance.

-scoped weapons have more felt recoil and slower return speed, the more magnification, the greater the effect;

-sighted weapons like holograms or red dots have lower accuracy at longer range, but a sharp increase in performance- lower turn bands, faster recovery time

-iron sighted weapons are roughly the same, though I standardized it in a way by class- AR's, SMGs etc. then adjusted for caliber/balance.

- you can also make adjustments for attachments- increase performance for bipods and foregrips (lessen recoil and increase return speed)

and attached weapons like masterkeys or m203's decrease felt recoil but slow down return speed

I'd release it but I borrowed models from quite a few people with permission, but other than that it's not a fantastic mod, just a personal preference issue.

when set up in this manner the game now allows you more flexibility in weapon usage and the ability to adjust your tactics a litte (now you can bunker or raid a position) but you still cannot just run and gun it and the methodical approach still wins hands down. it's a must that you reduce the suppressed weapons performance and accuracy though, it's both factual and necesary to retain game balance. enjoy!