SPG-9 cant aim low enough

[badmojo420]

So you think it's fine that we have to aim down in order to hit things that are level with the emplacement? Wouldn't that start to eat up the already limited 3degrees of negative elevation?

Edit: Here's a picture of the scope just after building the emplacement. The bottom of the wall is level with the emplacement. The SPG-9 itself is perfectly level, yet the crosshair is way up above the walls.

[Rhino]

its due to the scope being angled upwards from the barrel, as it is in r/l to get the right trajectory in there...

[badmojo420]

I understand why the scope is like that, my point is that when you build an SPG on flat ground, you have to aim down to fire a level shot. Couldn't we push the front of the tripod into the ground some more so that it starts level?

[Rhino]

it dose start level?

[Bringerof_D]

So you think it's fine that we have to aim down in order to hit things that are level with the emplacement? Wouldn't that start to eat up the already limited 3degrees of negative elevation?

Edit: Here's a picture of the scope just after building the emplacement. The bottom of the wall is level with the emplacement. The SPG-9 itself is perfectly level, yet the crosshair is way up above the walls.

wait but it is level.... You're supposed to aime with the widest ^ symbol, not the +

[badmojo420]

I'll try to explain myself again.

This photo was taken after the emplacement was built, the SPG-9 was perfectly level, I hadn't touched it.

The blue line is the same terrain height as the emplacement. So a perfectly level SPG-9 should be pointing towards that blue line.

But, the red cross highlighted is where the round actually goes. Shouldn't the starting state of the SPG-9 emplacements be with that cross along the blue line?

[Ford_Jam]

It can already go down pretty far if you compare the two pictures (Even though they are built at two different locations I'm guessing?)

Like Rhino said, the reason the scope isn't parallel with the barrel, thats just how it is.
I'm guessing that the scope is designed like that because the round fired naturally arcs out of the barrel and travels upwards for some time? It's a recoilless rifle, not a self-propelled missle like from the TOW.

[badmojo420]

Ok, ok, but when the Russians set this up, do they level the barrel, or the scope?

The thing can point WAY up, and a little bit down. That first picture is pointed all the way down. So moving the center point down a bit is a huge gain in decreased elevation.

(Even though they are built at two different locations I'm guessing?)

Same location

Edit: If we ripped off the scope completely, why would a visibly level barrel fire way above a wall 100m away? Shouldn't it logically hit a couple feet off the ground on the wall?

You can see in the pictures that when the barrel is level, the scope is also level. Wouldn't the + symbol be the one level with the ground? Not the scope circle?

I believe that in real life they would level the barrel to the earth, and then when they looked into the scope for the first time, they would naturally bring the barrel up a bit to center their view with the horizon.

The center of the scope circle would be pointing into the ground when the real barrel is level with the earth.

Sorry I had such a hard time explaining that. It's a bit complicated.

[Ford_Jam]

I know what you're trying to say, but look how far away the wall is in this ss you posted



Lets say, hypothetically, that wall is 400m away (I know it isn't, but hypothetically) then the barrel which is parallel with the terrain (as shown in the 2nd ss of this post) will hit the wall. All of those small chevrons below the + are where the projectile will hit at the numbered intervals

So the chevron that alligns with the #4 will hit the target at 400m, the round wont fly on a flat trajectory parallel to the ground like the barrel is, but that's just how it works both irl and ingame. First it will travel up, "towards the +" if you will but then it will fall and land where the 400m chevron indicates.

[badmojo420]

The distance shouldn't matter with what I'm talking about. Nor does the trajectory of the round. I'm not asking that anything be changed with the way the weapon works.

When the barrel is level with the ground. The projectile should fly level with the ground and land on that same height or lower if the distance is greater. There is no way a level barrel should be landing hits higher than it's own height. That goes against physics.

So either the sight needs to be fixed so that the default elevation is the + being level with the horizon. Or you could just give it a bit more negative elevation and less positive elevation. And then live with the fact that watching 3rd person, the barrel will look like it's being pointed down slightly, while the round flies level with the ground.

Edit: Think about it this way, if we attached a laser pointer to the barrel of the SPG-9, would the round logically ever hit above that laser? That's exactly what happens in-game.

The projectile flies out of the top of the screen, while the barrel is configured to the center of the screen.

Edit 2:

I didn't move the mouse at all when i got on the SPG, it should have been level with the street. You can see the projectile flying above the white car. It did blow up the gary, but just barely clipped it.(in a previous shot)

[Rudd]

afaik the SPG is set up how it works IRL

its easy to use if you do a ranging shot

I think (but don't quote me) the largest symbol is 400m, with changes in 50m?

Its pretty easy to work, I'm sure some of you have seen me using this alot on NwA, PRTA and TG lately on insurgency to bombard enemy buildings. (and I killed 2 bradleys last night)

[badmojo420]

its due to the scope being angled upwards from the barrel, as it is in r/l to get the right trajectory in there...

In real life the scope is actually angled down, so that the barrel would point up to give it more distance when centering a target in the scope.

The problem can be easily seen by looking at it from a 3rd perspective, ignoring the scope and all that, a visibly flat barrel will fire a projectile that will gain altitude before it starts to lose altitude due to gravity.

This will allow a flat barrel 2ft high to clear a 10ft high truck at about 50m distance. That's freaking absurd!

Does nobody else see what i see? Am I going insane?

[AquaticPenguin]

I see what you mean after reading through thoroughly.

The screenshot Rhino posted shows the default angle is level, which means the '+' on the scope should be level with the ground to begin with. Since that's the direction the round is fired at. Instead the '+' is much higher up, so the scope needs to be angled down for it to be correct.

[badmojo420]

Exactly!

Now, excuse my poor paint skills, but here is a diagram of what's happening.

The blue is the sight line according to the + symbol.
The red is the path the projectile takes.

There is no reason a projectile should be gaining altitude after it leaves a perfectly level barrel.

Edit: basically, the projectile is set to the tilted scope, rather than the tilted scope being set to the projectile.

[ytman]

The screenshot Rhino posted shows the default angle is level, which means the '+' on the scope should be level with the ground to begin with. Since that's the direction the round is fired at. Instead the '+' is much higher up, so the scope needs to be angled down for it to be correct.

No. This is an ARCING trajectory. A wonderfully accurate one at that!

Obviously anyone can see that it is physically impossible for the diagram badmojo posted to be correct. No gun fires a round at anything other than parallel of the barrel. In his depiction he views the gun firing the round at a degree above parallel!

Another mistake is his perception of where the sight is. He places it above where it is either in the same plane or beneath... but most certainly not above.



Where the dotted line interacts with the trajectory is the perceived + at approximately 50m.

Maybe you aren't understanding that the in the game the scope is allowed to be a separate entity than the player/vehicle unlike normal player ballistics where the projectile always fires from the center of the screen.

[AquaticPenguin]

...

That came across more than a little patronising.

What I can see though is that in the screenshot of the reticle the '+' mark is above the horizon line, and the 3rd person view shows the weapon is parallel to the ground, how can it be fired parallel to the ground and yet the round somehow climb to the projection of the '+' mark...

[SnipeHunt]

if you can think of a good way (that will work with the BF2 engine) of making a user friendly way to be able to tilt the deployable without also making it look super odd I would like to hear it...

How about using the up/down keys (W S) to move it like left/right do. And let the mouse
do the usual movement within the range set by up/down left/right.

[badmojo420]

...

Sorry, you're wrong. I'm right. Do some research before making claims.

Maybe you aren't understanding that the in the game the scope is allowed to be a separate entity than the player/vehicle unlike normal player ballistics where the projectile always fires from the center of the screen.

It's actually an optical illusion in the game that makes it look like it has a normal trajectory. When you look in the scope, your virtual eye is in the center, but when you put the + sign on something, you're looking up an incline, even though it looks like it's straight.



So when we fire a projectile out of that + sign, it's actually going up as it gets further away, before the gravitational drop happens. Which works fine, but the barrel isn't calibrated to the + symbol, it's set to the center of the circle. So when you build an emplacement your "level" barrel is pointing into the sky.

Edit:

Now, going back to the original topic of the depression being too little, I think this picture will show how the bugged scope eats up a big chunk of the 3 degrees of depression. The blue was a guesstimate of what the 3 degrees is, and the red part is the amount we're losing due to the bug. You have to move it 1/3 of the way down, just to level it with the ground.




I think most of the confusion comes from the fact that the projectile doesn't actually interact with the visible barrel. So while the barrel looks fine, the virtual one that it actually uses seems to be pointing up a bit. You can't see this, until you run some logic tests. The picture I posted above showed the level barrel pointing into the bumper of a car, but back it up 30m and it goes clear over the car. I can't really spell it out any clearer than that.

[Mosquill]

I've looked at the code and discovered a bug that causes the firearm object to fire 1.25 degrees higher then it should. So the real depression limit is only 1.75 degrees instead of the intended 3 degrees.

I've fixed it for the next PR release.

[Rhino]

yep, nice find badmojo