I'm still not sure what you want, but this is what you can do, except creating a PERFECT BG in one go.
There's two lines in the map_data.sii file, these towards the bottom,
Code: Select all
ui_map_center: (-230640.0, 46000.0) // in editor coordinates #default (-155530.0, 24520.0)
ui_map_size: (6200.0, 6250.5) // map texture in real km #default (6450.0, 10850.5)
and the second you use to tell the game how many REAL kilometers horizontally and vertically the
BG image covers. You have NO opportunity to ROTATE the BG, so if that what you want, do it when
you create the image OR create a much bigger image and then rotate it in an app like GIMP e.g.,
then cut it to be square after that. Good Luck mate, but I have to warn you it's a damn tedious job
making a change to these parameters run the game, check, quit, change again, run, check ..........
EDIT: I doubt you will get anything from Wombats advice, but if you do, then I rest my case!