Arma: Mod Folders
Custom modfolders is a concept in Operation Flashpoint that allows addon makers and players to completely change most aspects of the game. They were introduced with the release of the resistance addon, which also became the first total conversion modification.
It has become a common practice to start mod folder names with a "@" in front of the name to distinguish them from other files in the Operation Flashpoint directory.
Making it Work
To load and use a modfolder it has to be added to the games startup parameter "-mod". This is easiest done by creating a new shortcut and editing the startup command.
If you for example are trying to load a mod named @test the startup command might look like this:
"C:\Program Files\Codemasters\OperationFlashpoint\FLASHPOINTRESISTANCE.EXE" -mod=@test
To load several mods separate their names with the ";" characther.
How it Works
The "-mod" parameter defines a search path the engine will use to locate data files when loading the game. It is important to remember that the RES mod will automatically be added first to the list of mod folders. This allows mod folders to change most aspects of the game without actually modifying the original files, it is also important to note that it allows a mod folder earlier in the search path to override data in a mod folder later in the path.
Example: If the game is started with "-mod=@wgl;@test" this would be the resulting search for the 'm2a2.pbo':
1: @test\addons\m2a2.pbo 2: @wgl\addons\m2a2.pbo 3: RES\addons\m2a2.pbo 4: addons\m2a2.pbo
The search will end at the first match.
Since most players today have a very large number of extra addons installed it has become a common practice to divide them into addon modfolders. The benefit of this practice is that the engine only has to load the addons in the modfolders specified by the player, lowering memory usage significantly. To create an addon modfolder simple pick a name and create the directories "@myname\Addons\" in the Operation Flashpoint directory. Next place all addons you want in this modfolder into this directory and add "@myname" to your "-mod" list when these addons are needed.
To make this easier you might wish to create several shortcuts loading different modfolders.
The main drawback of this technique is that it's hard for other players in multiplayer games to know what kind of changes you are playing with as modfolders can be used to make beneficial configuration changes to the game, in other words cheat.
Alternatively, you can use 'OFP Mod Selector', by Operator of Dissidence.