- Mac OS X: Applications/FlightGear.app/Contents/Resources/data/Scenery
- Ubuntu: /usr/share/games/flightgear/Scenery
- Windows: %ProgramFiles%/FlightGear/data/Scenery
Directories are being read from left to right. For each scenery tile, FlightGear will check whether it exists in the first directory. If not, it will move on to the second directory and so on. Directories should be seperated by colons, like:
So, FlightGear searches the scenery path in order. The first terrain found for each tile is loaded. Objects for a tile are loaded from all directories visited before (and including the one where) the terrain was found.
The path can contain objects only, terrain only or combined scenery directories. The Airports and Model directories (which are late additions) complicates the scheme a bit as they can only be in combined terrain and objects directories. (I think that the first found such directories are used).