questions about the deck gun stabilisation

[tater]

kv29 managed to get ONE of the guns to properly destabilize, actually.

At the time we were sort of thinking inside the box. Strikes me you just clone that gun X times, with the clones pointing at the other models, change tham ammos, etc...

Might work. Let me find the mod for you.

http://www.subsim.com/radioroom/showthread.php?t=117430

Read the whole thread.

[Sammi79]

Right, I have now successfully enabled 'welded to the boat' behaviour for the deck gun zoom sights on both the German 8.8cm & 10.5cm with the result that instead of the crosshair following the true horizon, it now follows the horizontal plane of the boat. When the crosshair is inline with the true horizon, the boat can be considered a (fairly) level firing platform.

The guns actual elevation still tries to follow the preset range to the true horizon - I can't find a way to link the actual elevation with the boats horizontal plane. I am currently using KV29s nice simple method of setting the elevation speed low which significantly inhibits (not quite removes) the effectiveness of this auto-levelling. The end result so far is a much more challenging and presumably more realistic portrayal of deck gun operation. On a calm clear day the gun is easy enough to aim though ranges past about 6 Km hits are rare. With 5mph winds it is still possible to be accurate up to about 4 Km if the target is close to your 0' bearing though some timing of shots will be required. As the windspeeds and therefore wave effects increase, more timing of shots is required and the error multiplying effects of range further limit the ability to consistently hit anything unless firing carefully timed shots at closer ranges. In 15mph winds I found it very difficult to be accurate at more than 1.5 Km. It's not as hard as I thought it would be, you get used to firing when the crosshair passes the horizon quite quick and with practice you will always achieve a higher hit ratio than your crew can, as they do not seem to time their shots very well. The zoomed out view remains stabilised but as the gun itself is not it is very difficult to judge when the boat is level to give an accurate shot. I will have a look at the fleet boats for stock and TMO next but it is gonna take some time as I have to work.

The change involves editing the .dat file for each individual gun model, rearrangeing the hierachy somewhat specifically the camera positions are moved to different parent objects. Then Cameras.dat must be edited to set the actual positions of the deckgun cameras as they are no longer following their original position, also the movecannon parameter "lookathorizon" must be set to false. These fixes keep the zoomed sight level with the boat at all times.

The .sim file for each gun model must also be edited so the speed of the turrets elevation is too low to keep up with the pitch/roll of the boat (0.2 or less), this is AFAIK the best way to negate the gun auto levelling.

[Sailor Steve]

What you are doing is cool. Keep up the good work, and I hope you solve the last problems.

[Rockin Robbins]

I like what I'm hearing! Keep up the great work.

[LukeFF]

Same here.

[Sammi79]

OK, I have put the modified files in a JSGME ready 'mod' package, compressed to .rar and uploaded to filefront :-

http://www.filefront.com/16441969/RDG_v00.rar

This is the first test version of my attempt to destabilise the deckguns, It is designed to work with SH4v1.5 stock.

There are still problems, but I've been having a lot of fun testing it so far so see what you think. I think it will be possible to do the same for the major mods also, they would need to be included in updates for these mods though as there are significant changes in Cameras.dat. There are 2 testing missions, 1 US and 1 German included and a readme for info regarding the actual modifications and instructions on how to install.

I would still like to find a way to stop the auto-elevation of the gun - have the aimpoint based on the imaginary horizontal plane of your boat as opposed to the actual horizon but as yet no idea how to go about that.

Any feedback would be much appreciated. Maybe this wasn't a hopeless endeavor after all?

[Sammi79]

Bear in mind that the wind/wave physics in the stock game are minimal so this will be the easiest version - I have working fixes for the OpMonsun files aswell but with the environmantal changes the mega mods bring It becomes much more challenging to place rounds on a target at any sort of range in 5mph+ winds.
ATM I'm hesitant to make complete versions of this mod specific to work with TMO or OpMonsun as I am not totally satisfied with the slow elevation fix, until I have exhausted all possibilities of truly stopping it. Slowing the elevation is beautiful for the fact it can be made easier(faster elevation) or harder (slower elevation) to suit taste/desire for realism, but there will always be a (however minimal) levelling effect. for true realism this should not move relative to the boat at all unfortunately if it is set to 0, the gun will no longer move up or down making targetting completely impossible. 0.2 seems to be a good balance between difficulty and slow gun movement.

[Sammi79]

As I have been working away since may-september this was put on hold. Now I've been back a few weeks I have some progress to report.

In my game currently, ALL the deckgun views are destabilised now.

As I tweak I have learned some interesting things.

in Cameras.dat the 'AimCannnon' controller is for the AI. You can remove it and the crew will no longer point or shoot the gun. It also resets the gun to its default position when the gun is unmanned.

The 'MoveCannon' controller allows the player to aim and fire the gun, without it there is no player control. Unfortunately the auto elevation of the gun is a factor of this controller, and AFAIK apart from inhibiting it there is no way to completely stop it.

So there it is, If anyone's still interested. I will keep tweaking it and see if I can come up with anything more.

[rein1705]

As it is right now on my boat...
My gun crew can hit a freighter at 2,000 yards one out of about every ten or fifteen shells in pretty good weather ...
That of course makes me cuss and holler... pace back and forth and sometimes throw things at them from the bridge before i storm down there and take the gun myself.

[Sammi79]

Hi Rein1705, have you modified your files as I have? I would be interested to hear how you approached the problem. Oh, and which version do you play, PTO or ATO? with which mods?

[rein1705]

I have not changed the deck gun's property's myself no.
I play Fall Of The Rising Sun V1.5 (PTO U.S.) with RUIM and the Office links & .50 Cal mod, New Narwhale 1.8.4 and TMO interiors with several sub skin mods. The only modding ive done myself is put a 40mm AA gun on an S-42 class boat and figured out the rotational values of said weapon so it'd rotate 80 degree instead of 35*
When i was saying my crew fires wilder than a drunk Cowboy shooting at a rabbit i was being truthful but thats because i have a green crew right now in my current boat and they really are THAT bad.

[Sammi79]

Yeah the AI has quite a defficiency encoded! even when they mature they'll still miss seemingly easy shots.

When you take the gun yourself though, it is far too easy. Of course you have to guess range at first, but when you've scored your first hit you can pretty much gaurantee successive hits, as the gun automatically levels against your boat pitching and rolling. Also the gunsight is unaffected as if the whole mechanism was gyroscopically computer stabilised very much like a modern tank cannon.

I've been working to make the operation more realistic, with some success, like I said in my current game the deckgun view & the sights are static with the boat now, and the gun elevation moves too slow to keep up with the pitching/rolling, so you have to wait for a firing window, when the boat is level (or as close as you can get). The red cross on the deckgun view and the crosshair on the sight tell you when the boat 'is' level as they pass the horizon, so if you want your shell to travel at the indicated range that is the time to fire. This makes the AI even less apt at controlling the gun however, as they simply fire as soon as the gun is loaded!

I've never tried FOTRS, I use TMO for US-PTO games, and for a while I've been stuck on U-Boats anyway.

[Rockin Robbins]

Sounds like you're making great progress!

[Sammi79]

OK, here are some screenshots to describe the way the modified deckgun works. All shots were taken in a test mission with 7mph winds and clear weather. In all views there is no vertical movement, apart from the pitch/roll of the boat. First, the unzoomed deckgun view which is currently locked to the gun (no elevation - the gun moves relative to the view when adjusting range whereas moving left and right trains the view and gun), The red cross shows the particular pitch/roll of the boat ;



Then at first level of zoom ;



Lastly at full zoom ;



In all views, the pitching of the boat is noticable and it the second full zoom view some roll is also apparent. The target is a stationary T3 tanker at about 5150 meters, from this point I commenced firing 10 rounds out of which 2 hit, considering that I knew the exact range and have had a lot of practice, this seems reasonably realistic to me.

[Sailor Steve]

An amateur historian at the old Warships1 boards did a lot of studying and calculated that overall the average hit rate for the entire war was about 7%, and that he narrowed it down to 12% under 10,000 yards and 2% at 20,000 yards. If I remember correctly he also said that those numbers mostly were from surface battles, which meant sophisticated fire control director equipment.

So 20% at 5000 yards using iron sights seems a little high to me, but on the other hand that's getting very close to point blank range, so it's probably about right.