Map GenerationFirstly install the tool Universal Map downloader.
http://www.allmapsoft.com/umd/ Use this to create a map of the region of the globe you are interested in. I use zoom level 7 and specify a 10 degrees of latitude/longitude area. I also use yahoo maps as a source, I think they work better.
In the directory you specify in the tool, you will find a directory with the name of your map.
In this there are a bunch of files.
Obviously we have the actual map, but you also have a log file. Open that in your favorite text editor.
In that you will find a call to
gdal_translateOn that line you will see four numbers which are the actual latitude and longitude of the map.
If you asked for a map from latitude 40, longitude 0 to 50,10 .. you don't get a map from 40,0. You get a map that contains your desired region. The actual extents are the ones in the log file.
Copy these four numbers into your scratch pad and copy the bitmap into the games Maps folder.
Then in your text editor create a new file and create two lines of text (with carriage returns at the end).
"map name without extension"
"start longitude" "start latitude" "end longitude" "end latitude"
So it will look like this
Maps/yahoo2
-11.25 60.25398111661686 0 48.9224992600023
Save this in the maps folder.
That's it. The map is now in the game. I scan all the text files in this directory and build an atlas which the game can query to get a map of anywhere in the globe.
You only have to do this once. Once the map is in the game it can be used in any mission regardless of timescale. The only thing that matters is that the region of the globe is covered.
I will also be using the same technique for height maps. All you have to do is change the map source in the map downloading tool to be height map data instead of map data.
I hope that is clear.