may someone tell me the format of the 3D models files or how to edit them to paint them for example? Is it possible to add them on the 2D map?
Here's my 0.02, not quite sure but looks like the 3D models date from the Talonsoft days, they are very similar (if not the same) to original Campaign Series unit images from that era.
Looks like there's four versions, one ending in 'g', 'o', 't', and 'y' respectively.
So looking at i10025g.bmp for instance, I'd guess
'i' is an identifier of a sort?
'10' is the country code? 10 is the US in Talonsoft's Campaign Series, so maybe here too. At least those look like US tanks there for instance. (00 is Soviet Union, seems to check, 01 Germany, ditto...)
'025' is the individual unit ID?
then, the letter is a camo color?
'g' is gray
'o' is olive
't' is tan
'y' is yellow
In Campaign Series, the four camo colours were "Normal", "Early War", "Late War", and "Snow Camo". So something different here perhaps.
The files seem to be 8-bit bitmaps, 256 color format in other words. That is a PITA format, but with Campaign Series, the game engine did not mind saving them as 24-bit bitmaps. So if you wanna work with them, the very first thing I'd try is just to convert one to 24-bit color and to check if it works, and if it does always convert first then do the editing.
Hope this helps.