Nav Map Tools

[Maky]

Hi People,

I have been playing Silent Hunter 3 For quite some time with G.W.X and Commander.

I have come across something that is bugging me intensely and stopping me playing on full hardcore settings with no map update which I don't want to do.

When I'm plotting ranges etc on the Nav map the ruler seems to be unaccurate.
let me explain...

If you go to full zoom or most other views in Nav map view, notice the scale in the bottom left corner. in full zoom its 50-100-150-200-250m.
Now when you take out the ruler tool and drag it beside this this scale, what happens?
It dosn't measure properly.
It's always 50m out.
It only correctly points out at 250m 500m 750m 1000m
this is highly frustrating to me and I was wondering if it can be rectified somehow.

Has anyone else noticed this?
I'm guessing not a lot of you play with no map update/god eye disabled.

***update***
I am currently reading a tutorial by wazzoo who notices this annoying problem and states his hope that it is rectified with a patch.
this is a old tutorial so does anyone know of a mod / patch???

[Pisces]

There is no problem, no bug! And therefore no patch neccessary!

The length of the line is rounded to the nearest tenth of a kilometer, as it should! So if the line is shorter than 0.05 km (50 meters, or 1 square at the deepest zoomlevel) then it is shown as 0.0. If it is longer than 0.05km, but shorter than 0.15km (150 meters, 3 squares at the deepest zoomlevel) then it shows as 0.1. Same goes for longer lengths. Whatever length the ruler shows, you can be sure that the actual length of the line is never more than 50 meters longer or 50 meters shorter.

And you gain nothing in aim-accuracy or hit-succes with being more accurate to 50 meters. Believe me, I know, I'm a nitpicker by nature! Averaging distance travelled over longer time is what helps you the most. As speed is what matters the most in leading torpedoes on target. Not range. Besides, at 8km (stock 3d horizon distance) 1 degree of bearing is 140 meters wide. Making plotting errors of 50 meters in range a moot point.


p.s. what I did notice is that the thick and thinner gridlines exchange thickness as you pan the map. The thick line always jumps back to the end of the mapscale. Real maps do not do that as your eyes scan over it.

[Maky]

As it should be?
Every time I use it for ranging a target I have to deduct 50m from the length.
I don't see any benefit of the way it is at the moment.

***update***
Can you explain what problems would arise by having it change to its correct distance properly.

[Pisces]

Why would you need to deduct 50 meters every time? The number on the end of the ruler is as long as is shown, give or take 50 meters to either side.

The way you suggest, or atleast the way I think you want to see it:

any length ...
upto 100m is shown as 0.0,
from 100m to 199m as 0.1,
from 200m to 299m as 0.2,
from 300m to 399m as 0.3,
so on and so on...

This way the displayed number can be 99 meters off from the actual value, instead of being within 50m as it is now. Or 199m is shown as 0.1, while it is actually twice as far! 299m is 50% further when being reported as 0.2. Now, this is a really extreme short range which you won't encounter playing the game. (you'll be dead by collision or shell fire) The difference of 50m or even 100m at normal ranges of 4km to 16km are negligible. What does 50 meters or even 100 meters matter at 7 kilometers? 0.7% or 1.4% respectively from the actual value. That is pretty accurate to scientific standards. But we are not in a laboratory in this game. There is a war going on! In reality distance measuring wasn't anywhere near as accurate. And even the watchofficer in the game can only report range in steps of 100 meters.

Really, take the value at the end of the ruler as given and you're never 'too far off'. (always within 50m, sometimes a bit more, sometimes a bit less)

[Pisces]

I suspect you are trying to plot and measure speed with the 3 minute 15 seconds rule, correct?

Well this is good, but do not measure between successive plots! Instead measure between the 1st plot-point and the 5th, so there are 4 spaces of 3.25 minutes in between there. Then measure this distance and divide the number by 4. Now you have a speed value (each 100m represents 1 knot in 3m15s period) that is on average accurate to 0.25 knots. Do it over 10 spaces (easier to dive by) and you have averaged the inaccuracy in speed down to 0.1 knots. Better than you can set the target speed dial. But 10 spaces take 32 minutes. All it takes is patience.

[Pisces]

Ok, which value is wrong according to you? Each gridsquare is 50 meters in size, this is the deepest zoom level. The vertical lines indicate the distance from the 0-point in steps of 100 meters.



The numbers at the horizontal endpoints are always within 1 square of the vertical lines (either on the left or on the right). This patern continues no matter how long the line gets.

[Maky]

I see what your getting at.
What I guess I'm failing to get at then is, would it be possible to mod the ruler to display 50m AND 100m AND 150m AND 200m AND 250m.
It may not matter to accuracy but I would prefer it this way.

If the Watch officer for instance says range 1100m bearing 40, do you measure to 1.1km or 1.2km? if the actual range is 1190m it would be 1.2km because it is within "not more that 50m either side" like you say.
Or do you go with 1.1km where your now out by 90m.
Initially you don't know its 1190m so you have to guess.
This is just an example. I don't use the watch officer.

***update***
you did your last post as I was writing mine. I do get what your saying.
But what about when you trying to pin the enemy merchant on the NAV map at a fair distance to figure out its course?
If you get its range wrong on two observations won't you get its course wrong?

Anyhow, have you got any links to reading for showing me how 50m discrepancy don't matter in calculating a firing solution at a rage of 8km.
I'm not calling you a liar or picking trouble I would just greatly like to read more on this as I have a interest in it and you seem pretty knowledgeable on it.

[Pisces]

Originally Posted by Maky

I see what your getting at.
What I guess I'm failing to get at then is, would it be possible to mod the ruler to display 50m AND 100m AND 150m AND 200m AND 250m.
It may not matter to accuracy but I would prefer it this way.

Ok, so you actually mean those circles on the line (at 0.3 km, or 0.5, 0.8, 1.0 if it is longer). Those are meant to give a sense of length, not the actual length. But if the line is longer then the 0.3 and 0.8 won't show, but in regular steps of 0.5 or 1km. Sorry, afaik (as far as IS known) those routines are hardcoded. Nobody so far has been able to mod the way those lines (or the other tools) are printed on the map. Except maybe for finding their color in some datafile. But I'm not sure of that.

If the Watch officer for instance says range 1100m bearing 40, do you measure to 1.1km or 1.2km? if the actual range is 1190m it would be 1.2km because it is within "not more that 50m either side" like you say.
Or do you go with 1.1km where your now out by 90m.
Initially you don't know its 1190m so you have to guess.
This is just an example. I don't use the watch officer.

I would plot 1100m as a line of 1.1 length. To be totaly honest, I don't know for sure if the watchofficer rounds of his 'measured' range, or if he just truncates the lower digits to steps of 100m. But I do not plot at those short ranges, perhaps only in dire situations as dense fog. I would have plotted his course well before that at distances between 8 to 16km(GWX modification) while I am trying to overtake him on the surface at the edge of visibility. No need to get so close to plot it's path.

***update***
you did your last post as I was writing mine. I do get what your saying.
But what about when you trying to pin the enemy merchant on the NAV map at a fair distance to figure out its course?
If you get its range wrong on two observations won't you get its course wrong?

This is where time averaging comes into play. If the time between the plots is quite short then plotting inaccuracy (both bearing and range) and can lead to significant errors in course. The target has hardly moved forward, but seems to have stepped to the side a bit. Or the plotting error might even have placed it behind a past plot if it was large enough (like through manual periscope stadimeter). But if you wait longer before the 2nd plot is made, then the course error fades away with time. (Same position error, further away leads to a slender angle)

However, if you wait too long (extremely long actually) then there is the chance of a course change by the target. So the suggestion of averaging over multiple 3m15s periods is better in this case. You get to see more often where the target is. Sometimes you might get a plot that is way out of the rest. That could be mistake somewhere in the process. Blame it on Bernard sharpening your pencil causing it to break. Or it could be the first sign of a course change. So, be patient and await the next to see if it also falls out of place. If it doesn't repeat then you ignore the odd one and just fit a line through the rest as neatly as you can. When you know the target course (and speed) and where it is on the map in relation to you then you can set course to overtake and get to the attack location.

Anyhow, have you got any links to reading for showing me how 50m discrepancy don't matter in calculating a firing solution at a rage of 8km.
I'm not calling you a liar or picking trouble I would just greatly like to read more on this as I have a interest in it and you seem pretty knowledgeable on it.

No links. Just paying attention in math-class. I allways try to draw things out on paper. Making an imaginary target and see how his position changes (straigt line, constant speed, fixed time intervals) result in lines of bearing and range. Or in reverse: just taking 2 range/bearing values out of the blue and see what course and speed results from this. But I'll try to make another example drawing with the in-game map showing this tomorrow.

[Maky]

Thanks I think You have sussed where my frustrations are routed from.

I never get problems AFAIK from testing when calculating a ships speed using the 3.15 observations even with only 2 observations.

I usually get problems when trying to get the targets course.
It makes sense now that you have mentioned waiting longer before observations. any slight error will seem more intense at short distance whereas leaving more time for the ship to travel levels it out.

When I was doing it before I often got results as if the ship was doing evasive
maneuvers

Nice one.

[Pisces]

Originally Posted by Maky

Thanks I think You have sussed where my frustrations are routed from.

I never get problems AFAIK from testing when calculating a ships speed using the 3.15 observations even with only 2 observations.

I usually get problems when trying to get the targets course.
It makes sense now that you have mentioned waiting longer before observations. any slight error will seem more intense at short distance whereas leaving more time for the ship to travel levels it out.

When I was doing it before I often got results as if the ship was doing evasive
maneuvers

Nice one.

If it detects you then it starts doing evasive maneuvers, zig-zagging a bit. That's why I try to avoid getting too close. But they also might have warships in the vicinity and they will be directed toward you once detected. That's the last thing I want to happen. So I do my best to stay hidden all the time.