UE3Tools

Unreal Engine 3 package toolkit — opens cooked .upk / .u / .umap packages, extracts every object into editable text and asset files, and compiles edits back into loader-ready overrides. No .upk is ever repacked.

Why it exists

UE3 assets are only editable if you can recover their types, and cooked packages don't carry enough type information on their own — a TArray tag never says what its elements are, an immutable struct is written positionally with no field tags, and native serialization after the property stream has no tags at all.

UE3Tools solves that the way the engine does:

• Hand-coded metatype bootstrap. Binary deserializers for UClass, UStruct, UScriptStruct, UFunction, UState, UEnum, UConst and all fourteen U*Property kinds. These can't be data-driven — reading UClass requires already knowing UClass.
• Lazy schema database driven by imports. When decoding hits a type it doesn't have, it follows the import reference into whichever package under --game-root defines it, the same way ULinkerLoad::VerifyImport does. Results are memoised, cycles are broken by a visited set.

The result is one code path for every game, and no per-title offset tables.

Where to go next

At a glance