[REL]SH4 Stock Mast Height Correction
 

Several days ago I submitted a question regarding the Add-On as to whether it addressed the problem of correct mast height (Let's Butt Heads with an Add-On). As I suspected, it does not. I’m usually not one to criticize WITHOUT giving an alternative solution, so here is mine. It took me a couple of days to run my tests on all stock Japanese warships and most merchants, plus a couple of U.S. warships, 61 ship classes in all.

My tests have to include various ship positions (AoB) because the game does not calculate AoB within the Position Keeper to give correct adjusted range. I’m not an expert on the U.S. sub equipment of the day. Why doesn’t the Position Keeper (PK) recalculate a ships range when it’s at different angles to the sub? For instance, at 1500 yards distance (center to center), the carrier Taiyo has a found range of 1482y at 90 degree AoB. At 25 degree AoB it shows a range of 1430y, about 50 yards difference. Besides setting the Gyro angles for the torpedos, why shouldn’t the PK adjust range to the same centered figure the sonar or the computer found range give you? This isn’t my real subject topic for this thread, but I will point out that’s why I have the manual “Ship Centered, Accuracy Fix” modification to refocus a range estimate to the center of a ship, not out at the masts that are rarely centered.

To provide greater accuracy of manual range finding using the masts, an average had to be made from the various angles, and then a math formula was used to correct the mast heights. I have put the results into a downloadable file using Jimimadrid’s JTxE text merge utility. JTxE is a good tool for changing just portions of files that other mods may change; leaving them intact, just changing particular areas. If we all (modders) offered JTxE formatted files, the conflicts of incompatibility would be lessened to the general community. JTxE needs to be installed in the root directory of SH4 (like JSGME). The “SH4 Mast Correction” is JSGME compatible, so place it in the JSGME “MODS” folder, activate as you would any JSGME mod, then close JSGME and open JTxE. You will find the mod here as well. Move it to the “Mod’s Used” panel, then close JTxE and run the game. To uninstall the mod, just remember to remove it from JTxE first, then JSGME. If you wish, you can manually change the text figures (workable with Notepad) in the various ship .cfg files. Just follow the folders and file structure that is given.

The SH4 Mast Correction mod can found here:
http://files.filefront.com/SH4+Mast+.../fileinfo.html


In testing I found corrections had to be made to all but 1 ship class (the SubChaser was good for the average). Others needed minor tweaking, less than ¾ of a meter off. While 26 ship class’s were near or over the “1 meter height plus” difference. A handful needed greater than a 2 meter height change. So you may be wondering what a change in 1 meter of mast height does to manual range finding. Well, it depends on the actual mast height of each ship.

For the taller mast height ships in the range of 45 meters (150 ft)
1 meter difference = about 30 meters in range difference


For ships with heights of a little greater than 30 meters (100 ft)
1 meter difference = about 40 meters in range


Ships with heights of a bit greater than 20 meters (75 ft or so)
1 meter difference = about 50 meters of range difference each.

That difference can add up quickly if the mast height is off by several meters. The worst offender was the Destroyer Mutsuki which had an 8 ½ meter difference in stock mast height after calibrating it to a 1380m (1500y) actual distance.

This calibration process I refer to is simply taking a stationary target ship at a known distance and comparing the range found with the Stadimeter to the actual distance. I worked up a formula to help in making the corrections and I will give it to you for future use. I’m doing so not only for those who would like to check for theirselves how to achieve a greater accuracy in range finding, but for the modder who develops a new ship class and perhaps feels a bit responsible to provide the correct mast height for good range calculations. For those modders that do not pay attention to such things, perhaps you the community need to ask them why they do not.

To use the formula, take the manual Stadimeter found range (take several readings to make sure you have the correct figure) and divide the mast height into it. Take the figure and round it off to the nearest hundreds past the decimal point and set it aside for later. Now subtract the manual found range from the actual predetermined range and take the difference between them and divide the figure you just set aside into it. You should have a figure that looks like 1.53048 or 0.24153 or whatever. This is the amount of mast height that needs to be added or subtracted with the original mast figure to calibrate it for the true range to target. I use the process that if the Stadimeter manual found range is greater than the actual, and then subtract the difference from the original mast height. If the actual found range is greater than the Stadimeter’s, then add the difference to the mast height. The next time you run your test the true range to target should be showing in the PK. At least as much as the game calculations will allow, The game does not recognize math figures greater than a tenth past the decimal when figuring range. It rounds them off to the tenth position. This means if you’re within 10 to fifteen meters of the actual correct range, you’re as good as the game will allow for accuracy.

I did this for a reason, to show that accurate mast calculations can be achieved (although there are short comings outside of my control) to manual targeting. I do this without a workforce of computer specialists or a quality control team that has allowed the problem to exist for a year after the game's release. The ringing out of another 10 dollars from us in order to have the Nazi’s come to the Pacific bundled with a 5th patch (that has few corrections to the overall game) is just about all I can stand from UBIsoft.

So if I understand this correctly, this is a substitute for your SCAF for those who want to use mast heights for their targeting?

Yes, that's correct. It gives the gamer corrected mast heights (within the limits of the game engine) to have a more accurate manual range determination. It's as simple a mod as I can make (just changing mast heights) without having to be compatible with any other mod or whatever patch UBIsoft throws out.

Although this does not address the possibility of new ships being entered from the various modders or from the developers, that's why I explained the process and formula for figuring corrected mast heights. It puts the burden of giving the correct mast heights for manual range finding on the shoulders of those that are creating the ships. If they do not wish to do so, then your only alternative is to follow the process yourself, of testing and calibrating, to make range finding more accurate.

I believe my Ship Centered, Accuracy Fix is much more accurate than this basic approach, but I have no plans to dance to the UBIsoft beat with their paid for patches and "Upgrades". If the SCAF mod works with 1.5, then keep using it. If not try this "SH4 Mast Correction" version as an alternative. If they do not, then you should beat down UBIsoft's door, demanding better from them. :up:

Couldn't have said it better myself. I agree whole-heartedly! :up:

Now...speaking of the real deal (read:SCAF)...how's that progressing? ;)

Ok, sometimes my memory is as long as my ........ ! What exactly was it that I'm suppose to be progressing on? :doh:

Join the club! My memory sucks too! :p What I do remember is updates for the latest RSRDC update (cause I use RSRDC, obviously ;))

I like this. I use mast heights all of the time to calcualte range and I usually hit the target, but once in a while I will have a bad miss. This explains why.

Hi All

Its been a very long time since i was last here :damn:


Regarding Mastheight targeting - once uppon in time i made corrections to the scene.dat file to fit some more realistic scope images that someone produced. The camara angle was off so the mastheight were off as well.

Was this carried on to the later big mods?

Hello Mav87th, no the change you speak of never caught on. I remember using your mod "Mavs Camera Mod" to see if it would make a difference in being able to "see" the mast top better in some of my trials. It did, since it magnified the view from stock, but the manual targeting accuracy REALLY went south with the mast figures the game used. The AngularAngle parameter within the camera.dat file really messed up the solution. The stock mast heights were off the mark with the stock AngularAngle figure anyway, your figure did no good to them either. It did give us the idea that a greater magnification for view would be helpfull.

I've been looking at the inaccuracy of mast height calculations since the game came out. Krupp was doing so in the metric option system, I'd been centered in the imperial side. When patch 1.3 fixed the metric calculations by not having a redundant extra conversion of meters to yards made, the system of measurement calculations were corrected. However, the mast height figures were still off for most ships. The mod that started this thread changes the stock mast heights. For many ships a signifigant change was made, for a few not so different. The point is the ship mast heights were calibrated within a test mission to be accurate for the distance they were positioned. Some were as much as 200 to 400 yards off. You couldn't hit those ships unless you were knocking on their door step.

One note about periscope magnification, there is a mod that increases the view without messing up the Stadimeter reading for manual targeting. It's a great help in "seeing" the top of a mast or whatever reference point thats used for marking range. I know it's not historicaly accurate, but it does a great job. Maxoptics2 increases the periscope view by 100%, the binoculars by 250%. It was first introduced by WernerSobe, I made some changes and additions and have it in a couple of versions. It's on the Ship Centered, Accuracy Fix mod post, just scroll down for the download link.



Oh Yea, THAT!!

I'm working on it now, except not right now, I'm writing this reply now!!! I think I'll be done soon, maybe today. :D

Well my mod were mostly for manual targeting with a wizzwheel, in witch case you would have VERY acurate readings with the scope ticks.

So with this mod does the ships fill the correct amount of "tick" in the scope as well as giving a correct readout on the steadymeter?

I don't think im understanding you right, ´cus what i did was making the angular angle of the periscope to the value that a periscope of the class is. Its not a figure you should be messing about as it will screw up the visual presentation of the target in the scope tremendously. ie. a ship of X meters in length fills Y amount of periscope at Z yards, if you do not use 57,265 as angular angle (how many degrees of vision that is presented from the left to the right side of your screen) the zoom level will be going tits up.

I guess ill have to take a look at it again.

I have never used the periscope hash marks to judge range to target. Not to say that's not do able, or not historically accurate. I suspect this was the primary method a captain used to mark a range reading rather then any other. Since the game offers the Stadimeter for manually marking range I've concentrated my efforts on correcting it's shortcoming.

As far as just what the hash marks mean is a mystery to me. First mark = ?, second = ?? and so on. If you know at what mark a particular height would be aligned, for a particular distance, then I can see the magnified view could be changed to match the position.

This Maxoptics2 mod simply magnifies the view by 100% over stock to allow for an easier Stadimeter fix on the reference point (mast top, funnel, what have you). It's not ment to have a releationship with the hash marks for figuring range. With this method, there is no skewing of the calculations for manual finding range with the Stadimeter as there was with the mod you released. It uses the same AngularAngle figure the stock game has, it simply magnifies the view, with no ill effects to range finding with the Stadimeter.

The hash mark method was what we had to use in SH1/SHCE. Still had to do some paperwork to work out a solution - the whiz wheel helped a lot. That's where the idea was started with having to take two bearing readings over a period of time and letting the game do some of the calculations for you. It was a good compromise between point and shoot and doing it the hard way.

No - it was not the AngularAngle parameter. I tested it extensively and the stadimeter range was (and still is) exactly the same no matter what value the Angular Angle has. I just redid this test as i have made a new version of my older mod.

My mod does not touch at all with the workings of the in-game stadimeter, but fixes the visual image you get of the targets through the binocular, Uzo and both periscopes so the zoom is correct (using BetterScopes 1.3 overlay) with regards to Linier Field of View and Angular Field of View.

For an extended explanation (better then the old one i gave in the mods :damn: )

http://www.subsim.com/radioroom/showthread.php?t=133207


I thought Krupp fixed that back in time??

btw. the real boats did not have anyting that calculated for an offset angle (mast being closer or further away with inc. or dec. AoB. for one simple reason - the masts were VERY seldomly used as a measurement fix. More used were the decks as a deck usualy has a certain height when a ship is build. Masts were cut down and extended on nearly all ships from what the ship was listed with in the production specifics, but the decks were not.

I just looked through my old notes and your absolutely correct. I see your original mod parameter for the AngularAngle was 60 (stock 62.4814) with the magnification set at 1.5 for low power, 6 for high (stock 1, and 4 respectively). With these settings the Stadimeter readings were very close to the stock Camera.dat figures. I am incorrect to say your mod had something to do with incorrect manual range finding. I'm sorry for that statement, I needed to hunt for my paperwork before coming to that conclusion. Although there are other ways of messing up the Stadimeter reading, the AngularAngle must not be one of them.


His fix is different then mine. Some of his mast heights are off by a meter or more. It could be he didn't use a magnified view to "see" the top of the mast correctly. This game is very subjective in nature for finding manual range to target. One person may see the top of the mast differently then another, poor eyesight, poor video card performance etc. The game divides the periscope screen into horizontal pixel lines, each line represents a different calculation sum with the given mast height that's reported in the TDC. One pixel width high or low, can throw off the range to target by 10 or more meters on average at a 1500 yard distance. This difference depends on the placement of the Stadimeter image either high above the waterline, or low, closer to it. The devs did this to have a larger inaccuracy reading with objects at greater distance (lower to the waterline), and less difference in accuracy with a range marked at the top of the screen (closer to the sub).

How much width is a pixel line you may ask? There's two pixels in the width of one of the rectile hash marks you use for marking range to target in the periscope screen. Actually there are three different range finding pixel lines for each hash mark (the top of the mark, the center of the mark, the bottom of the mark). Each pixel line will give a different range to target depending on where the Stadimeter's ship waterline image is placed. Even a twitch with your index finger can throw off the Stadimeter's range finding value. Just like "squeezing" the trigger of a firearm, so should you be carefull in clicking the mouse.

In the first post of this thread I gave an example of what 1 meter of difference can mean to a manual found range. I also took the time to calibrate the distance from several AoB angles, then average them, for gaining the correct mast height. If we were going to view a target at the same angle then the average would be unnecessary, but that's not the case in practice. So there is a difference in my work than Krupps, Always has been, he originally worked with the metric option, I worked within the imperial side.

Way cool - ill be trying out your mod some more.

From the first readings it looks very precise :up: