Custom scenery comes in many forms.
You can have fictional custom scenery, detailed custom scenery, shared model custom scenery, procedural generation (OSM) custom scenery, and many other types.
Nevertheless, all these custom sceneries have to be installed.
In your command line, there is a parameter called –fg-scenery. This parameter is used in the format:
(Top folder is the folder which has “Objects”, “Terrain”, etc inside it)
One should add the path to where you downloaded the custom scenery to to that parameter. Personally, I use ffgo; however, I believe that for two seperate folders, the command is:
With a semicolon dividing the two sceneries. If you use command line, you will know more about it.
Thus, for a custom scenery inside C:/Users/Lego/Documents/GitHub/RJBB-fg-CustomScenery, I just do:
fgfs.exe –fg-scenery=C:/Users/Lego/Documents etc etc
This works for all OSes; you will have to correct the path to the scenery of course.
FGRUN, the good old classic, will be used up till 2016.1 (this February). It has been replaced with a QT based launcher since 3.5. Anyway, for those who loved it, never fear! You can still use your old FGRUN for the new FlightGear, and probably it will still be included, but not as the default launcher.
Anyway, on the very first page, behind the aircraft page, is a page where one sets up scenery, aircraft, executable, and FGDATA paths.
This photo is from an ancient version, but it still is the same principle!
One would add the extra paths by hitting ‘ADD’ below the list of paths, and then simply adjust as needed with the arrows to determine which scenery to use. For example, say I had TerraSync and a custom scenery, and I wanted to load the custom scenery, I would select the custom scenery (turn it blue by clicking) and move it to the top. And of course, turn off TerraSync on the settings page.
There is an extra scenery paths dialog on the last page. Unfortunately, it causes the launcher to crash for me. Therefore, when I use it, I would tend to add it manually; ie in the command line options input box.
FFGO, the python 3 based launcher, has a scenery path selector, accessed from the Settings menu. You can add them manually, with semicolons between them, or use the FIND tool.
There are many other launchers; the principle is the same. Just add the sceneries in order of priority.
Hope this helps!