Resource keys

Resource keys are the main way files are stored and referenced in many Maxis games. They are an abstraction on top of the filesystem. In simple terms this means they are just file paths.

Format

A resourcekey consists of three parts.

1. The instance
   • A 64bit unsigned integer
   • This is like the file name, as its just that, an FNV64 hashed version of its original file name.
2. The type
   • A 32bit unsigned integer, it's the file type, for a list of knows types check here.
   • In most cases again a FNV32 version of the original file type.
3. The group
   • A 32bit unsigned integer.
   • This is like a folder (also an FNV32 hashed string), but can be 0 if the file is meant to be at the root.

We usually show these files like this: 0x00000000!0x00000000EE93FAC8.dds. Where 0x00000000 is the group and 0x00000000EE93FAC8 is the instance¹.

The Editor also displays them like this 00000000 - 00000000EE93FAC8.

You may also sometimes see them referenced as ITG, because of the order they come in.

Examples

Here are some examples:

These names were found by hashing strings found inside the game files. And comparing them against all known resource keys. Ones that could not be recovered like this may have partial or incomplete names. Like 0xCFFED122!0x000000002FA92BDF.material just becomes decoAppleBowl/2FA92BDF.material (Found in Objects.package).

Pattern

import type.base;

struct ResourceKey {
    type::Hex<u64> instance;
    type::Hex<u32> type;
    type::Hex<u32> group;
};