Mod directory's. Children says folder, men say dir ;)
Custom mod dirs is a concept in Operation Flashpoint and Armed Assault that allows addon makers and players to completely change most aspects of the game. They were introduced with the release of the OFP: Resistance addon, which also became the first total conversion modification.
To load and use a mod dir 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:
To load several mods separate their names with the “;” character, like this:
You can create batch files (.bat) to start your OFP/ArmA. Here is one good full example of our bat file:
START "" /D"%CD%" /B "%CD%\beta\arma.exe" -mod=beta;x\terrain;x\coc;x\pmc -nosplash -world=empty -profiles=d:\ArmA
The “-mod” parameter defines a path the engine will use to load data files when loading the game. It is important to remember that the OFP: RES mod will automatically be added first to the list of mod dirs (OFP only). A mod dir can contain all the data that your OFP / ArmA install dir can contain. This includes missions, campaigns, and addons subdirs, etc. The most common use of mod dirs is to organize addon .pbo files.
Since most players today have a very large number of extra addons installed it has become a common practice to divide them into addon mod dirs. The benefit of this practice is that the engine only has to load the addons in the mod dirs specified by the player, lowering memory usage significantly. To create an addon mod dir simple pick a name and create the directories “myname\Addons\” in the Operation Flashpoint directory. Next place all addons you want in this mod dir 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 mod dirs.
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 mod dirs can be used to make beneficial configuration changes to the game, in other words cheat.
In ArmA, it is possible for addons to modify classes in other addons, including those in the game's core “addons”. If the user installs two addons that try to modify the same property of a given class (for example, the model property of the basic soldier class), then obviously both addons can not work as intended (together in the same install, that is).
In these cases, there is almost nothing that the user can do to determine which addon takes “priority”. Inside of the addons themselves is a property called “RequiredAddons”, which determines addon load order, regardless of mod dir order.