GST itself has a very detailed explanation in Danish.[0] But basically, two of their employees worked to created the converter. They even include a table list of GST's own descriptions of terrain types and what Minecraft biomes they were converted to.
They don't have underground data, so some simple steps have been taken for each area based on a general idea of the underground (e.g. Bornholm's underground becoming stone).
As for buildings, they know the shape of buildings, but not their texture, so they are merely randomly generated in 'unrealistic colours' (as they describe it).
As the map data is updated each quarter (3 months), the Minecraft data will also be updated.
It's a very interesting read, I recommend you learn Danish and read it!
They don't have underground data, so some simple steps have been taken for each area based on a general idea of the underground (e.g. Bornholm's underground becoming stone).
As for buildings, they know the shape of buildings, but not their texture, so they are merely randomly generated in 'unrealistic colours' (as they describe it).
As the map data is updated each quarter (3 months), the Minecraft data will also be updated.
It's a very interesting read, I recommend you learn Danish and read it!
[0] http://www.gst.dk/emner/frie-data/minecraft/om-frie-data-i-e...