This article is a work in progress and is incomplete.
Resource.cfg governs how The Sims 3 looks for additional content that is not directly referenced by the game itself.
Resource.cfg file is basically a very limited type of script. Each line represents an instruction.
DirectoryFiles <path> [argument, ...]
- autoupdate - If new files are added after the game has scanned this directory, it will pick up any changes
Instructs the game to look for files on the real file system, depending on the settings given before this instruction was used.
This instruction will cause the game to look for additional Resource.cfg files in every directory the path to the files is in.
Ends a Select block.
FileType <typeid> <extension>
Adds a file type registration, for use with DirectoryFiles.
Group <groupid> <name>
Names a group id.
PackedFile <path_to.package> [arguments, ...]
Instructs the game to load a specific package file. This instruction will cause the game to look for additional Resource.cfg files in every directory the path to the package file is in.
Defines priority of following instructions, higher priorities instructions override lower priority instructions.
This causes the game to look for Resource.cfg files in this directory and all subdirectories.
Essentially an If branch, the block inside a Select and End pair will only be executed if the given condition is true.
When this Resource.cfg was found using Scan, it will stop the scan from going any deeper into subdirectories.
How The Sims 3 find Resource.cfg files
The Sims 3 by default looks for two Resource.cfg files, through these, other Resource.cfg files are loaded.