A problem with the omnimeter

[in_vino_vomitus]

So. I recently enabled map contacts, which makes determining course and speed ridiculously easy. I'd like to turn them off again. Especially since I've been itching to use the omnimeter that's part of the OTC mod. However, for some reason, the sliding scales seem to be cut in half. I thought this might be an issue with screen resolution, but everything I've tried so far yields the same result. Can anyone help?

I wasn't sure if this would be a better query for a PM, but on balance I thought if someone else has the same problem then an answer here would be useful to them also - and if anyone else has had this problem and fixed it, I don't mind where the solution comes from :)

finally a word of thanks to Cap'n Scurvy for the work he's put into this mod. If I could buy you a beer for it, I would do....

[merc4ulfate]

What exactly is the sliding scale you are referring too? You can disable the contact with a check box in game play options.

[in_vino_vomitus]

There are two sliding scales on the OTC in-game Omnimeter - I attached a pic, but it's not great - anyway, for whatever reason, the two sliders only have half of their scales showing, and the index marks are hidden, which pretty much makes it useless.

One thing I really like about the pre-radar game is the way you have to gradually build up a solution from purely visual and sonar cues. Map contacts on is a good way of simulating range estimates by an experienced crew, but the trouble is, you know that they're exact. I'd rather make my own estimates, plot them myself and firm them up on the go. I do own a slide rule, but to be honest my maths isn't good enough to convert telemeter info to range and AoB. also it irks me that there's a gadget in the game that I can't play with. :/\\!!

[CapnScurvy]

I'm suspecting your running a mod conflict. What specific mods are you running? I'm going out on a limb looking at your signature and seeing:

TMO 2.5
1.5 Optical Targeting Correction 031312 for TMO 2.5
1.5 OTC Realistic Scopes for TMO

Is the version of TMO 2.5 actually named (found in JSGME's MODS folder)....."1_TriggerMaru_Overhaul_2-5" ? It should be.

The only way the Omnimeter could have the sliding scales out of sync with the meters base is by the menu_1024_768.ini file having been corrupted. I would first remove all mods from "Activation", then have JSGME's menu "Tasks.../Compare Snapshot" run to check your stock game files. I'm assuming you took a clean install "Snapshot" of your stock game files just after adding JSGME to your game (no mods added yet). If not, I would reinstall the game (follow the instructions found HERE (http://www.subsim.com/radioroom/showthread.php?t=133290)). Then install JSGME and take the "Snapshot". Re download the mods again, then put them into JSGME.

Moving mods in and out of the game with JSGME is the safest way......BUT, its not fool proof. There are plenty of ways of screwing up your stock game files with mods (that's why JSGME has the Snapshot feature.......To check if there are any screw ups). Mod files themselves can get corrupted if pulled out of "order of activation" so always remember to follow the rule....."First one in, last one out".

[in_vino_vomitus]

Thanks!! - I'm right on it :)

[in_vino_vomitus]

I didn't re-download the mods again, but the snapshot comparison didn't show any problems after I de-installed them - when I reinstalled them the omnimeter was as before - Is there any way this could be because I'm running this on a laptop?

[CapnScurvy]

I've not run the game on a laptop, so I really wouldn't know. I've always thought of a desktop machine to be the computer of choice for games. I wonder what your Windows screen size is on the laptop? What's the resolution/aspect ratio you're using for the game? If they're different from each other, I wonder if you're experiencing some sort of screen resizing issue?

Are you running the game in a window? I've heard this can cause screen resizing problems.

[in_vino_vomitus]

Yeah - I agree about the desktop being the machine of choice, but this is all I've got :( to it's credit it runs the game pretty well. This is the first real issue I've had with it. - anyway, it's a minor annoyance. I'm pretty sure I can make one if I can't get the in-game version working. Thanks for taking a look :)

[in_vino_vomitus]

I had to have it - So far it seems to work pretty well........

http://farm4.staticflickr.com/3769/9179479376_298e431917_c.jpg

http://farm4.staticflickr.com/3682/9179483070_ccf62b75ec_c.jpg

[TorpX]

Not bad. What do you have it mounted on?

[in_vino_vomitus]

I had a sheet of black plastic lying around. What it's called I don't know, but it's about 1/8" thick, rigid, like perspex, but it's opaque, so I cut and glued it to make a baseplate and sliders then enlarged and printed the omnimeter graphic from the OTC docs, drew the face on graph paper, using the printout to measure the scale increments and then stuck that to a sheet of stiff card, cut it into the appropriate strips and stuck those to the plastic. I used a plastic document pocket as a clear cover to keep my grubby handprints off the scale.

What was instantly apparent was that once you have a target ship id'd and the Telemeter scale set, range estimates are pretty much instant, unlike the stadimeter, and you can get workable ones at some pretty huge ranges. I didn't intend to use it when I did, I was going to do a training mission with map contacts on to check it for accuracy, but when I found myself in the strange situation of having visual contact but no radar return, it seemed a perfect opportunity to try it out. I have no idea how accurate it actually is yet, but the estimates I got from it, fit very neatly into the plots I'd made using radar over the previous couple of hours.

[CapnScurvy]

"Necessity is the Mother of invention"!!


Like the authentic Omnimeter, it was hand made by the machinist on-board, with the tool used by one of the "Firing Party" of the boat. This original Omnimeter from the USS Cod Museum (in Cleveland, OH) was hand made out of aluminum.



http://i175.photobucket.com/albums/w132/crawlee/CodOmnimeter.jpg



The original post from a friend named Gino was started some years ago (found HERE (http://www.subsim.com/radioroom/showthread.php?t=169857)).


One thing I found interesting about the original Cod Omnimeter was it had a correction to the original design. After I corrected the games optical view to mirror real life dimensions, I found the original sliders position for marking the targets height dimension was off by a fraction of an inch. As the below image close-up shows, there's the original mark with the "triangle", and a smaller "notch" made just a fraction of an inch away for setting the slider to the estimated height figure.



http://i175.photobucket.com/albums/w132/crawlee/CODOmnicloseup.jpg



That "notch", just to the right of the triangle, is much more accurate than using the original "triangle" spot. The crew obviously found this to be so (as I did using the tool in-game); they simply corrected their calculator with a new "notch" on the original.


I'm suspecting the tool was hung near the periscope (maybe even on it) by the round loop hole at the one end.

[in_vino_vomitus]

Interesting thread - I had another chance to check out the tool when I re-did the attack I messed up so stupidly yesterday. So far it seems to be way preferable to the stadimeter, just because it's easier to use. Probably takes much less than 5 secs of periscope exposure, and having compared the readout from the stadimeter with the omnimeter - there seems to be a discrepancy, but it's not big enough to matter, and I've no reason to think the stadimeter range is the correct one anyway. So, again, thanks for an excellent piece of work :)

[CapnScurvy]

Since there's no way of me checking this with a real life periscope (I have looked through the display periscopes at the Nautilus Museum in New London, Conn. however, the stadimeter function is removed on these display models), I believe the game's stadimeter is much less accurate than the authentic one. The game adds an "error" to the view which I believe to be excessive to the real thing.

In-game, the stadimeter will produce an error in range finding if you're just one pixel width off the exact height point of measurement. This error is only a half dozen yards off if the reading is made towards the top of the periscope view. Towards the water line, the error can be hundreds of yards off with just one pixel width of inaccuracy.

The error was probably put in-game to simulate the idea that a range measurement at longer distances (towards the waterline) can be less accurate than one made at close range (the measurement height spot is higher in the view). More pixel widths away from the "sweet spot", the error get's multiplied. The fact that the Telemeter hash marks on the scope lens are two pixel widths in size, tells you just how easy it is to get an inaccurate range reading when using the stadimeter. A small twitch with the mouse; the sub or target ship moving to the wave action; the fact that the mast top can "flicker" with the poor rendering by the video card; all produce poor results with the stadimeter.

There's nothing we can do about the error in pixel width, its hard coded in game, along with the math formula that makes the range finding. :/\\!!

[in_vino_vomitus]

I have no problem with the error factor - to be honest I'd find it more frustrating if measurements were spot on. One thing I noticed comparing Stadimeter and Omnimeter estimates was that, so far there seems to be less error with the latter, but you need to be good at judging fractions - also in low light, you have to be aware that the top of the mast might not be visible. Thing is, Stadimeter error is automatically included in solution, whereas the Omnimeter gives me more control. Since I've barely used the thing so far, I doubt I'm getting the best performance out of it, but I have to say it's becoming the tool of choice. I fired ten torpedoes at a convoy last night, using only info gained from the Omnimeter - well - I worked out the speed during the approach, but they changed course just prior to firing, so the rest had to be worked out from scratch. I was firing at four targets, the convoy was about 3500 yards off my beam, I got two impacts, at least two duds and at least three prematures - I guess I'll need to turn duds off in order to properly evaluate it, but given my prior success rate using the PK and curved fire, I can tell you it's an improvement. I'm actually a pretty good shot, but the trouble is I've thought that means I ought to be able to shoot torpedoes too. Letting go of that misapprehension was painful, but productive :)

Anyway - thanks for a great tool :)

[in_vino_vomitus]

Something that occurred to me whilst trying to work out where the top of a mast was, was that if the relative dimensions are accurate in the RM I might be able to guesstimate the funnel or bridge height - also if I got a masthead reading in good light, that I was happy with, then I could use the same procedure for calculating AoB to get a height for the bridge or a funnel, for use in poor light. I'll start looking into that directly. What do you think? is that going to be expecting too much?

[CapnScurvy]

No that's not too much to expect. If the optical view is corrected in-game. When corrected, the ability to measure accurately becomes much more effective. In real life, the subs WWII Telemeters (the hash marks on the lens) would subtend approximately 52.5 feet if the object was 1000 yards distance from the lens. One degree of Height/Length at 1000 yards distance is 52.5 ft. The Telemeters are one degree apart. When you have 32 of them (spaced equally apart), and you can count 16 degrees to the edge of view (if the periscope bearing is moved to the edge), and the objects you're viewing is 1000 yard distance from the lens.......the optical world is right. That's how OTC corrects the world view, by correcting the viewable distance between the center of the lens, to the edge of the lens, with objects at 1000 yard distances. There should be exactly 16 degrees of bearing length between the two points.

If an estimated height was 100 feet for a particular spot on the target object, and the measurement in Telemeters below this point was half a Telemeter @ 1000 yard range distance. The spot in question would be estimated to be 74 ft in height. It's how things were figured when only one estimated height measurement was known. I'm sure every Captain remade his estimates of height when he realized his range isn't correct after an errant shot was made and all other possibilities were reasonably accurate.

My plan is to make a better Recognition Manual with several different height measurements on key spots of each ship. This way a player can choose the best place to make a measurement. The games process of inputting dimensions will have to be changed since the Attack Data Tool doesn't allow for specific height/length dimensions. Also, the Stadimeter only allows one measurement to be entered for each target. But, this has been in the back of my mind for quite some time. It's quite do able, but it takes time.

[in_vino_vomitus]

Let me see if I've got this right. The scope is at low power and the masthead is 100 ft high - A whisker over 1 3/4 increments tall, and the top of the bridge is half a telemeter increment below it. The target is 1000 yards away so we can call the bridge height 74 feet?

[TorpX]

Someone here developed a technique in which he used the target's length to measure range. Of course he had to estimate the AoB, first. He claimed to get good results with this.

[in_vino_vomitus]

That's interesting. I suspect that as long as you have a positive ID and a good idea of the AoB that would work pretty well - Something I just found out though is that ID'ing the target correctly seems to be pretty vital. I picked up a Hakusika Maru and wrongly ID'd it as a Biyo Maru - height and draft are much the same but length is very different, which had the result of throwing my AoB estimates out. I didn't question the ID, and I didn't use the ID Ship feature - I assumed my estimate of target speed was wrong. Long story short - missed with three torpedoes - sent a further two out with a correction to the gyro angle and hit it.

It's interesting to note that if I'd set up for a DoK shoot, the errors I'd made wouldn't have mattered, and if I'd paid more attention to detail I'd have known my data were being skewed. - In my defence, the discrepancies I saw with the data weren't huge, but they turned out to be enough, since they prompted me to change the target speed I had set and that and the incorrect AoB, did the trick.....

To be honest I see little point in turning the PK on for a single ship, but I'm trying to use it more so's I'm good when I need it.

[CapnScurvy]

Let me see if I've got this right. The scope is at low power and the masthead is 100 ft high - A whisker over 1 3/4 increments tall, and the top of the bridge is half a telemeter increment below it. The target is 1000 yards away so we can call the bridge height 74 feet?

No, at low power magnification a single degree is as below.....52.5 ft = 1 degree @ 1000 yards distance. If a mast height was 100 ft tall, at low power magnification, the telemeter increment would be a wisker under 2 full degree marks. Two full degree marks only covers 105 feet. It's much closer to two full degree marks than saying its a bit over 1 3/4. Sounds like I'm spliting hairs but it will make a difference.


http://i175.photobucket.com/albums/w132/crawlee/HighLow_Power_zpsa52aa6ec.jpg


You are correct to think that if the bridge top is just half a telemeter distance lower then the mast top, then its measurement is 74 ft tall. Its just that one quarter taken from 2 full telemeters is a shade under 1 3/4 tall @ 1000 yards distance.

[in_vino_vomitus]

Yes - as it happens I'd mis-copied the telemeter index mark by about 1/16" - fixed it now :) Thanks

[CapnScurvy]

The beauty of the American periscope using a 1.5x magnification at low power, compared to 6x at high power.....with a 32 degree optical field-of-view......is the different magnifications can easily be multiplied or divided into each other, yet still come out with a reasonably accurate measurement.

The Germans didn't have this symentry with their optics. It's probably why SH4 became such a "bastard child" compared to the other Silent Hunter series games from UbiSoft. I don't know if SHIII and SHV has the same problem in rendering their optics correctly as SH4, but they really screwed the pooch for the American Fleet Boat in the Pacific.

[in_vino_vomitus]

I have to ask - was that a design feature or a happy accident? Also I realise I'm kind of stereotyping here, but that's the kind of detail I'd expect a German engineer to come up with

[CapnScurvy]

I have to ask - was that a design feature or a happy accident? Also I realise I'm kind of stereotyping here, but that's the kind of detail I'd expect a German engineer to come up with

For all I know we may have had a German defector figuring out the authentic American optics. Anyway, I'm guessing it was no accident.

[in_vino_vomitus]

Yeah - that was badly phrased - Of course it wasn't a coincidence. Thing is it's a pure design issue - there's no technology involved per se, so I'm surprised that U-Boats didn't adopt it, but since I know nothing about periscopes that's not saying much. Was there any advantage to their design?

[CapnScurvy]

The German periscopes were similar to the American versions in regards to the magnifications used, however the FoV were different. Here's an excerpt of a British intelligence report for the captured U-Boat U-570 (http://uboatarchive.net/U-570BritishReport.htm):

Optical Arrangement

Magnifications: 1.5x low power / 6x high power
Angular field : 38° low power / 9° high power
Exit pupil: 3.5 mm. / 3.5 mm

8. The top reflector gives an elevation movement of from - 15° to + 20°.
9. The optical performance in both powers is satisfactory.


Since the American version had an angular field of view of 32 degrees for low power, 8 degrees for high power, it seems to lend itself better to correspond to each power. Perhaps it's due to the fact that the American unit of measurements can easily focus on fractions (two quarters = a half. Or three 1/3's = a whole) better than the metric system? I don't know, maybe I'm showing my ignorance! :88)

[in_vino_vomitus]

I chuckled at the thought that you might be showing your ignorance. I wonder what that makes me? The metric system has a lot to recommend it, but as you point out, it doesn't handle fractions very well - basically it only has 1/10 and powers thereof. I was thinking about how the omnimeter has changed the way I play, and how tools in general seem to change the way we think about a task as much as the way we perform it, so it seems a perfectly reasonable idea that an engineer brought up thinking in tenths, simply wouldn't think of making a scale that worked as a multiple of 4.

If I'd had this to play with in 1975 I wouldn't suck at maths the way I currently do. - we're going about education totally the wrong way.....

Also the report looks pretty interesting - Bookmarked.....