I wonder if somebody might be able to walk me through taking a screenshot and importing it into Gimp please? Also what tools to use in Gimp to make a tileable texture?
I have found a few tutorials but none that describes the above.
First open a site that has good satellite images. Google earth comes to mind first so let's go with that one to begin with.
You look around, zoom in and out until you find a landscape that you think might look good as a texture. usually, I've found it takes about 10 to 12 texture try-outs until you do get one good usable texture. But let's assume you find a good landscape. When you do, simply press the 'PrtScr' (print screen) key. This captures the image on your monitor and puts it in your memory.
Now in either GIMP or in Paint Shop Pro (a more versatile program, especially the older versions like PSP7) or whatever, use the paste command (ctrl+v) and voila, the whole of your screen will be imported.
Now you need to crop the screencap into the correct size texture you wish to use - either 512x512 or 1024x1024 pixels.
Handcropping is a laborious process. Getting a proper sized texture can be more easily done in this manner: make a new, blank file of the size you choose - 512x512 or 1024x1024. On the screencap, paste the new file INTO the screencap, keep the new selection floating ... then go to the screencap layer itself, keep selection floating and copy and then paste and you should then get a new image, of the correct size.
You must of course position the floating selection right over the portion of the screencap you wish to use as texture before copy/pasting.
Now you have a raw texture. You can clean it up if you wish, moving parts around with a clone brush, or changing the hue or whatever strikes your fancy.
To make it seamless in GIMP, use pull down menu in Filters/Map/make seamless/ ...
Note that in GIMP you get perfectly made seamless textures this way, but they are often too repetitive to use on a map.
I use
http://www.seamlesstexturegenerator.com/ to make seamless textures and it gives better results in my opinion. It's not freeware however.