This is his own words:
Terrain & Satellite
I got the DEM from Global Mapper (ASTER 30m res).
I got the Satellite pic from MySatellite (1700 tiles stitch from Google Earth) around 10700×10700.
I used Global Mapper to “rectify” the Satellite Pic to the DEM.
I used Global Mapper to “cut out” a region 20480×20480 and scaled it by 0.5 in the X,Y dimension and 0.8 in the Z dimension. I exported this to XYZ format.
I used Global Mapper to “cut out” the same region for the Satellite Pic and exported as a raster image to BMP (10240×10240).
I used GIMP to edit the Satellite Pic to ensure that the edges of the map matched the s_satout_co.paa for a smooth transition if players go off map (this version isn't shown below)
I used GIMP to create a layer for each of the main texture types on the map. (roads/runways, dirt tracks, sand, desert, mountain, rocky mountain, light grass, grass). I had the sat pic as the base layer and literally just painted the areas in each layer to the corresponding chosen layer colour.
Actually I've been using Visitor. The process that helps me is this…
Its just really to use template villages/industrial areas from previous maps as a starting point.