Real Navigation with SH3

[don1reed]

Aha, the trick, JMR, is I plot my last waypoint at the mouth of the harbor. It gives Python a reference point; all the saves of the game thereafter, supply's Python with the geographic codes (numbers that are divisible by 120,000)(don't ask me why it just does) wherever your boat is located. Its up to you the player to zero in with correct sight reductions to plot your location.

I'll show you a plot I'm doing in my present SH3 patrol as soon as I get it copied to imageshack.
edit:

Ok, here's a 3 star fix just outside of Lorient with attendant sight reductions.



cheers,

[don1reed]

oops, sorry Ischo, I apparently simul posted when you did and didn't see what you wrote.

Ok. Got it. I believe I know what you're talking about now. Yeah, this method isn't effected by that. Mercatur projection. I know it won't work if you try to sail a great circle course.

Here at least Python uses the numbers that the game produces and I'm always in the ball park. I've never been exactly spot on but that ok, I never been totally off the chart either.

So far with this method, by making typhoon quality wind >100 knots, the furthest off I've been is 43nm with the tests I've made using SH4.

This is navigation as I know it to really be. (less foul wx, of course)

You can always press CNTL Left mouse button to see where you really are if you're truely lost.

Let me add a VERY important point.

Just prior to going to Python to enter your data, you must do a SAVE. This save is what tells Python where your boat is last located for real.

So, every celestial sight you make you must also do a save-game and you must keep the name exactly the same each time. this writes-over preexisting saves as you know, but also eliminates some forms of cheating or do-overs, if you will.

Hope this helped.

[ichso]

Thanks, I will try the whole thing again on my next patrol.
The celestial navigation has always been very emersive for me.

I think, if you just do those position markings often enough, the problem I mentioned shouldn't be present such much as that one would recognise it. I will come up with experiences and results as I test it more extensively.

So, happy navigating

Nice drawings, btw.
I will stick to painting on the nav map first and use paper later, when I accidentely ereased all my ingame drawings

[Pisces]

I didn't have trouble going to the Stellarium site either this evening. Anyway, the right link to the site is:

http://www.stellarium.org/

[don1reed]

Here's a copy of how I've got my version of Python setup to work with SH3. If anyone's interested, you'll have to change the directory to suit your system.

You'll note after ...\\career\\...I've inserted my name, but this is where you'll insert your skipper's name.

Also, after... \\0\\...I've inserted my save-gave name = "100" plus add the file extension *.map. Whatever you call your saved game, this is where to put it in the Python script.

You'll have to use the same name for each patrol or change this script to reflect whatever new name you decide to use.

Oh, and btw, I've named my script: SH3random.py and made a shortcut out of it for the desktop so I can easily click on to it while SH3 is running.

You can copy mine, make the necessary changes using Notepad or similar writing tool and whatever you name it don't forget to place the extension *.py at the end. Once you get your copy of Python you'll see where to place this script.

Cheers,

#Python 2.5.2 (r252:60911, Feb 21 2008, 13:11:45) [MSC v.1310 32 bit (Intel)] on win32
#Type "copyright", "credits" or "license()" for more information.
#************************************************* ***************
#Personal firewall software may warn about the connection IDLE
#makes to its subprocess using this computer's internal loopback
#interface. This connection is not visible on any external
#interface and no data is sent to or received from the Internet.
#************************************************* ***************

#IDLE 1.2.2
#>>> #By Michael Jones, 01/01/2008.
#This program reads the latitude and longitude data for a
#sub in Silent Hunter IV and creates a startup script for
#Stellarium. This sets the Date, Time and Location of the
#sub in Stellarium, allowing players to use celestial navigation in the game.
#
#Modified by Castorp345 to include randomization, 03/24/2008.
import string
import random
random.seed()
#read savegame. Change the directory on the next line to point to SaveData.map in your saved game directory.
#NB you must have plotted waypoints in-game for this to work!
f=open("C:\\Documents and Settings\\Donald Reed\\My Documents\\SH3\\data\\cfg\\careers\\Don Reed\\0\\100.map",'r')
content= f.read()
f.close()
#find lat & Lon in the file
start = content.find("Waypoint")
longst = content.find("Pt0=",start)
longnd = content.find(",",longst)
latnd = content.find(",",longnd+1)
#convert to dec deg
longitude = float(content[longst+4:longnd])/120000
latitude = float(content[longnd+1:latnd])/120000
#get date, time, wind speed, & boat speed (input)
date = raw_input('yyyy/mm/dd :')
time = raw_input('hh:mm :')
wind = float(raw_input('wind :'))
speed = float(raw_input('speed :'))
#perform randomization operations on location coordinates
wind1 = random.uniform(0,((wind + 1) * .0083125))
wind2 = random.uniform(0,((wind + 1) * .0083125))
speed1 = random.uniform(0,((speed + 1) * .0083125))
speed2 = random.uniform(0,((speed + 1) * .0083125))
longitude = longitude + wind1 - wind2 + speed1 - speed2
latitude = latitude + wind1 - wind2 + speed1 - speed2
#Write startup script. Change the next line to suit for your Stellarium startup script.
stella=open("C:\\Program Files\\Stellarium\\scripts\\startup.sts",'w')
stella.write("date utc "+date+"T"+time+":00\n")
stella.write("moveto lon "+str(longitude)+"\n")
stella.write("moveto lat "+str(latitude)+"\n")
stella.write("script action end\n")
stella.close()
#now open stellarium and take your star sights

[jmr]

Seems like aaronblood's Mobo would be the perfect tool to supplant the traditional ruler/paper method for celestial navigation. Just grab a snapshot of the SH nav map, paste it into Mobo, set the scale accordingly and you're good to go.

At least I think it would work OK.

[6SJ7GT]

Don & all,
I don't have SH3, but hear my method works in SH3 also.

Here is a tutorial on a simplified method of celnav for the game. Thanks to Don for his help on this.

SH4 simplified celnav tutorial

Mike