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nuxil

bombs dont got air drag?

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Hi all

Is there no way to calculate how long a bomb takes before it hit the ground?

all the math formulars i find done add up..

i made a little test script. its not 100% accurate but enough to see that theres an problem with calulating droprate "meter pr second" of bombs Bo_GBU12_LGB

i used this simple script to find out max meter pr second "ms" for the bomb,

since real world math dont addup here..

but the bomb doesnt stop accelerating..

kinda strange if you ask me.

<table border="0" align="center" width="95%" cellpadding="0" cellspacing="0"><tr><td>Code Sample </td></tr><tr><td id="CODE">

_pos = getpos helipad;

_x = _pos select 0;

_y = _pos select 1;

_z = 9999;

_bomb= "Bo_GBU12_LGB" createVehicle [_x,_y,_z];

//_bomb= "T72" createVehicle [_x,_y,_z];

_bomb setpos[_x,_y,_z];

while {(alive _bomb)} do

{

_hightold = getpos _bomb select 2;

sleep 1;

_hightnew = getpos _bomb select 2;

_ms= _hightold - _hightnew;

hint format["%1",_ms];

};

i tested with diffrent objects

example:

T72 max MS is about 98.

M1Abrams same as T72

UralRefuel max MS is about 47.

HMMWV same as Ural

Bo_GBU12_LGB no MS. it just keeps accelerating

dosent Ammo have air drag??

can anyone explain this to me why this is so?

ps. funny thing is that. you can drive the vehicles after they fallen 9999 meter tounge2.gif

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even accelerating things have a velocity, if its indeed constantly accelerating put another sleep command after the format for about 3 seconds so you can see the number change

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Quote[/b] ]even accelerating things have a velocity

well as long as a object is moving it got a velocity.

my point was. the bomb "Bo_GBU12_LGB" dosent seam to have any air resistans.

you could just take away the getpos. and replace the wile loop with something like..

while alive do { hint format["%1",speed _bomb]; sleep 0.001;}

then you see the acceleration never stops.

it seams like air drag is ignored with the Bo_GBU12_LGB

it like thers no atmosphere for the bomb.  it behaving like its in vacume.

also.. if i put another sleep 3 in there.. the test script wound not be meter pr second. thats why i used 1 sec.

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i don't get it.

all things accelerate at 9.81 ms^-2 on earth it doesn't grow and it doesn't shrink and all things follow newton's second law

F=ma

terminal velocity is reached when <drag = mass * acceleration>.

Drag is a function of velocity^2, air density, specific coefficient of drag, mass and area.

but things in constant acceleration have constant velocity increase and instantenious velocity exists. so you script should still give you a velocity measurement. adding sleep 3 after the format would still give you meters per second, it would just refresh your format string every 3 seconds and not instanteniosly.

My vote would be that weapon classes don't give proper position readings or something like that.

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Quote[/b] ]all things accelerate at 9.81 ms^-2 on earth it doesn't grow and it doesn't shrink and all things follow newton's second law

ehh? all things on earth would accelerating at a rate of 9.8 m/s2 until it hit the ground if the Earth had no atmosphere

The faster an object falls, the greater is the air resistance acting on it. At a certain velocity, known as the terminal velocity, the downward force of gravity is balanced out by the upward force of air resistance and there is no further acceleration.

This dosent seams to applay for the GBU12

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ok we seem to be saying the same thing word for word so ill stop. in anycase all i was saying that no matter how GBU behaves ur script would still work if it falls, with atmosphere or not and the problem most likely is in how ArmA returns position values of GBU and not the physics.

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Right

anyways thanks for your reply smile_o.gif

i'll figure something out.

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Also the fact that your createvehicle the bomb...the weapon defines the initspeed and some other variables that define the ammo speed

Geometry weight also determines the bombs flight characteristics

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