They are not very difficult to make but it's a hard job finding all the track maps that fit together nicely, I made some for the last season GPGSL mod.
Therefor I imported all the circuit layouts into zmodeler and then took prtscreens and used those to make the maps myself.
After that it's all about the alpha channel, the layout needs to be white and all the surrounding black, if you just create the image like that the alpha channel is very easy.
Then you import it with GPI editor or how the program is called
If you are racing, keep on racing and get some points!
GPG Super League S11 | Driver #41 | Team-manager | Snake Motorsports Racing Group | Next Race: Emmeloord - Flevoland GP | Constructors: 10th | Best Race Finish: 1st
GPG Super League Season 9 Testers Champion*