Celestial Phenomena in SH IV

[Wolferz]

Rockin Robbins and I developed a difference of opinion regarding the moon and the way it's rendered in game. After some research I discovered, or should I say I had an epiphany,

You are correct Mr Robbins and I am as wrong as one can get. The game does not simulate the rising and setting of the sun and moon, at least not accurately, The sun is rendered to rise and set every 12 hours. No seasonal changes whatsoever. The moon will show full on the appropriate dates but, the transit is nowhere near accurate due to the fact that the devs ripped out the local clock we saw in SH III. Without that, there is absolutely no way that the moon could be rendered as in the real world. Then there is the problem of viewing location. The moon will look different between northern and southern hemisperes and programming a geocentric bodies' motion would be beyond the scope of this game. Well, it is a WW II sub sim and not a celestial mechanics simulator. It would be nice if someone could prove me wrong again but that isn't gonna happen. Is it RR? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

[RockinRobbins]

Ruh, roh..... You're telling me that you found no variation in sunrise and sunset times either? I was under the impression that they were OK. That's bad. I suppose I should have expected it.

I've been told that if you don't like the moon phase or position, just save the game, reload and it's somewhere else at a different phase. I haven't tried it but that also is plausible.

Somehow we get thinking that Silent Hunter 4 should be an accurate planetarium. Sure would be nice if it were, but maybe a dozen people in the world would notice if it were.

No, I take that back because we have a nice healthy group here and at Subsim who would like to do celestial navigation with the simulator. I don't think I would play the game like that but it would be fun to be able to do it.

In the meantime, there is a group that links game time up to an external planetarium program to do some celestial navigation. I haven't checked that one out, but good show guys on that one!

[K_Freddie]

Originally posted by Wolferz:
The sun is rendered to rise and set every 12 hours. No seasonal changes whatsoever.

The moon is a problem, but with regards the sun, go to higher latitudes you will get different daylight times. It is different to the USNO almanac, where at the equator, the times differences are about a minute, and gets worse at higher latitudes.

I busy trying to work out an SH4 sunrise/set almanac, and its no easy task. http://forums.ubi.com/images/smilies/10.gif

The local clock - in RL this is set to the each time zone that the ships is in, In sh3 this was the case, still must check for SH4. I think it's timezone is locked to your home base clock. ?
http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

[RockinRobbins]

Yes, it's tied into whatever your home base is. Does it change when your home base is reassigned?

[Wolferz]

I'm still spending time doing research but, as I stated above... with no local clock, sunrise and sunset can only be programmed for base time, with a very slight change as you move east or west from one longitude to the next. Remember the date line bug? That one was caused by the local clock being ripped out of the code. When you sailed out of Pearl, headed west, the code was getting confused when you passed the IDL. File that under things that make a CPU go huh!
Alot of us around here are intelligent enough to appreciate the more cerebral aspects of a simulation. Too many developers are forced by publishers to dumb things down for the less educated, instant gratification market. To their own detriment. IE:
Ubisoft Romania has recently finished the title, Tom Clancy's HAWX. My stepson has been hounding me to go halfers on it for the PS3. But it's just another dumbed down FPS flight sim. Nowhere near worth the price of admission. Just to show him that it's not that good a title,I rented it and
ripped through the first three levels in under an hour. Flying an F-18 and blasting numerous air and ground targets with unlimited uber missiles. There's not a decent dogfight to be found. Come to think of it, The title doesn't even live up to it's abbreviation..... High Altitude Warfare Xtreme. Spent most of that hour flying under 1k feet. LOL
Ubi, youse guys need to wake up and smell the escargot' Cause this dogfighter (no,I'm not Michael Vick) is hiking a leg in your flower beds.
I dunno, maybe I expect too much. http://forums.ubi.com/groupee_common/emoticons/icon_razz.gif

[Wolferz]

Good luck with that endeavor, K_Freddie.

Anyone who paid attention in science class should know about how our planet works within its heliocentric orbit. Unfortunately, Silent Hunter does not contain the programming sophistication required to render this phenomena. It wouldn't have been that hard to program the geocentric orbit of the moon. Or to program how it would be seen from any geographical location using polar coordinates, because the moon is in a finite orbit. It doesn't change. The Earth is also in a finite orbit around the sun. Granted, the orbit is eliptical but, it could still be programmed to render seasons, etc etc.

I need some ECT. Nothing like an electron induced convulsion in the morning. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

[Wolferz]

The local clock - in RL this is set to each time zone that the ships is in, In sh3 this was the case, still must check for SH4. I think it's timezone is locked to your home base clock. ?

Correct. The clock on your boat is set to base time. This can be seen by starting a career at Pearl and then transferring to the Asiatic fleet. The Shipboard clock will change to the new base time. The US Navy is adamant in regard to the time being correct aboard their vessels. Imagine the tactical nightmare that would be created for Command and Control if all of those warships had clocks set to different times. http://forums.ubi.com/images/smilies/53.gif

It would be such a nice thing if our favorite Subsim contained three clocks.... UT1, base, and local. MY USNO program uses the Greenwich Meridian (UT1) as the time reference. After calculating those figures I have to convert it to local time in the sim. PITA
DST anyone? http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

[K_Freddie]

Originally posted by Wolferz:
MY USNO program uses the Greenwich Meridian (UT1) as the time reference.
'Zulu' time is the favourite http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

If you have a look at the large map the game uses..
-Dimensions 21600x10800

Now
- 1 Nautical Mile = 1 arcminute (around the earth)
- 60 arcminutes = 1 degree (60 Nautical miles)
- 360 degrees around the earth = 21,600 Nm

Looking more than co-incidental at the moment.
Now 1 Nautical mile = 1852 metres, BUT the devs made 1Nm = 2000 metres http://forums.ubi.com/images/smilies/compsmash.gif
I've measure the time to travel 10 degrees and it's very close to 2000m per Nm.

I think they did this for simplification, but I think it has complicated things more ... http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

[Ducimus_Rapax]

the transit is nowhere near accurate due to the fact that the devs ripped out the local clock we saw in SH III.


This has always irked me. When i played SH3, i played the type9 because it was as close to a fleetboat as i could get, and i preferred long range patrols over the quick ones in the type 7. So i got real used to that local clock.

It needs to be present in SH4, MORESO then Sh3, and it's not there at all. Call it a pet peeve.

[K_Freddie]

Delayed action memory here ...'Old-Timers'

That 1Nm = 2000 meters seemed to be used to make the map zooming easier. The map zoom is scaled in metres per map pixel...

- so 21600 pixels at a 2000m per pixel will give you UBI's earth, somewhat bigger than ours http://forums.ubi.com/images/smilies/blink.gif
- Other map scale values are 50, 100, 200, etc metres per pixel

So all they have to do is expand a pixel to the zoom scale and draw it - easy for the map drawing.
http://forums.ubi.com/groupee_common/emoticons/icon_cool.gif

[Wolferz]

I think you're right on the mark with that line of thinking, K_Freddie. There would have to be some fuzzy math going on in there to render a working scalable map of the planet.
I reckon we can only chalk up the sun, moon, and stars as eye candy and nothing more.
Maybe my peeve comes from my love of space and all the cool shtuff that occupies it.

That , or I have too much space between my ears. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

M

[LouLewis1967]

Well this really irks me. I've searched this forum for info about sunrise/sunset and moon phases, and this thread seems the most definitive of all in saying they are not modeled accurately.

My experience lately is this: playing TMO 2.0 now, I have been taking sunrise/sunset observations for a couple of days on my current patrol south of Japan (~ 29 42 N 131 49 E, 16-FEB 42). Current day sunrise was observed at 0953 "Base time" on the watch. I went to the Naval Observatory site and generated the tables for my spot and date, and sunrise was supposed to be 2152. Sounds great, within a minute! Except I can not reconcile a timezone shift that would make sense! Pearl is GMT-10, Midway (where I actually started this patrol) is -11. Local time for my location is +9. No combination seems to work.

So, am I just chasing something that is not in the game, as this thread suggests? I would love to be able to generate twilight begin and end times for use in the game!

BTW, I noted the previous night (15-FEB to 16-FEB) was 12hrs 40min between sunset and sunrise. So it's not an even 12/12 split.

[RockinRobbins]

Solar system rendering in SH4 is just generally abysmal. You can travel to Dutch Harbor, Alaska and watch the sun rise straight out of the ocean, just as it would from Honolulu.

In reality, the sun travels mostly across the sky there. Here's a video I shot using Cartes du Ciel, a decent astronomical and solar system simulator. This shows from Dutch Harbor, the course of the Sun and Moon across the sky for most of the day, from 9:39 am to 4:51 pm, February 4, 1943. Just for spice, on that day, with maximum at 1:57 pm, there was a total solar eclipse, which you can clearly see in the animation! Notice that the sun never gets over about 20º above the horizon.

http://i196.photobucket.com/albums/aa293/RockinRobbins13/Silent%20Hunter%204/DutchHarbor02041943.gif

[LouLewis1967]

Well it is kind of a bummer. Obviously it is information a captain would like to have at his fingertips without having to lurk around at periscope depth. I know when the sub's lighting changes from day to night provides a good enough estimate, I'd still like to have some planning tools available.

[Blowtanks]

I've been told that if you don't like the moon phase or position, just save the game, reload and it's somewhere else at a different phase. I haven't tried it but that also is plausible.

I tried it and it appears to be not the case.
Three times I tried and every time my heading was 085 degress and the moon, cut through the middle, was 025 degrees.
I give a big http://forums.ubi.com/images/smilies/25.gif to those that took the time to figure this out. I simply assumed that the sun/moon had little meaning in the game since it is just a game.
With the bugs the game came out with who would of thought that UBI was interested in getting anything like the sun and moon correct?

[Wolferz]

Originally posted by Blowtanks:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> I've been told that if you don't like the moon phase or position, just save the game, reload and it's somewhere else at a different phase. I haven't tried it but that also is plausible.

I tried it and it appears to be not the case.
Three times I tried and every time my heading was 085 degress and the moon, cut through the middle, was 025 degrees.
I give a big http://forums.ubi.com/images/smilies/25.gif to those that took the time to figure this out. I simply assumed that the sun/moon had little meaning in the game since it is just a game.
With the bugs the game came out with who would of thought that UBI was interested in getting anything like the sun and moon correct? </div></BLOCKQUOTE>


One thing is safe to say, if you get caught on the surface under a full moon, you will be spotted easier than on a moonless night. So there is definitely a purpose to the celestial object known as Luna, in game.

[paulhager]

I posted some on this a few years back. I didn't go to high latitudes, though I did look for a Solar Eclipse, which didn't materialize. I used the Complete Sun and Moon Data for One Day (http://www.usno.navy.mil/USNO/astronomical-applications/data-services/rs-one-day-world) fairly extensively to plan attacks and it was usually accurate to a few minutes. (See, for example SS Balao, log excerpt (http://forums.ubi.com/eve/forums/a/tpc/f/6421019045/m/7011078336?r=7011078336#7011078336) in which I note the Moon rise at 1702 Zulu being "a few minutes early".) Generally, sunrise, sunset, moonrise, moonset, and lunar phases were quite accurate.

When you use the Sun/Moon calculator, you just have to make sure you are using Zulu time and have your longitude and latitude reasonably correct.

[MWolfe1963]

Didn't read all the post, but when I was near the N. pole at the ice shelf in December it stayed dark almost all day. Thought that was amazing that it was programmed that way. Went back once in the summer and daylight lasted longer. Can't remember the science behind the time schedule, but least we have that.

[Blowtanks]

One thing is safe to say, if you get caught on the surface under a full moon, you will be spotted easier than on a moonless night. So there is definitely a purpose to the celestial object known as Luna, in game.

That much I did take for granted.
I meant I didn't assume you could use the sun or moon to navigate, they are only there to help blind people, like myself, to know when its day or night. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif