UELib

The Unreal library (UELib) provides you an API to read (parse/deserialize) the contents of Unreal Engine game package files such as .UDK, .UPK. Its main purpose is to decompile the UnrealScript byte-code to its original source-code.

It accomplishes this by reading the necessary Unreal data classes such as:

UObject, UField, UConst, UEnum, UProperty, UStruct, UFunction, UState, UClass,
UTextBuffer, UMetaData, UPackage

Classes such as UStruct, UState, UClass, and UFunction contain the UnrealScript byte-code which we can deserialize in order to re-construct the byte-codes to its original UnrealScript source.

Additionally UELib is also capable of deserializing of many more data classes such as:

UFont, USound, UPalette, UTexture,
UTexture2D, UTexture2DDynamic, UTexture2DComposite, UTexture3D,
UTextureCube, UTextureFlipBook, UTextureMovie
UPrimitive, UPolys

Install

    Install-Package Eliot.UELib

Module	Version	License

• Usage: See the documentation for more examples.

    using UELib;

    // Instantiates a FileStream and deserializes the package's header, will also auto-detected a suitable build to associate the package with.
    var package = UnrealLoader.LoadPackage(@"C:\Path\Package.upk", System.IO.FileAccess.Read);
    Console.WriteLine($"Version: {package.Summary.Version}");

    // Necessary if working with packages that have been cooked for a console platform, and IF the build was not properly auto-detected.
    // package.CookerPlatform = BuildPlatform.Console;

    // Initializes the registered classes, constructs and deserializes(loads) the package objects.
    package.InitializePackage();

    // Now we can iterate over all the initialized objects, but beware! This includes fake-import objects.
    foreach (var obj in package.Objects)
    {
        // If positive then we have an export, or import if negative, if null, we are working with a 'None' object, but this shouldn't occur here.
        if ((int)obj > 0)
        {
            Console.WriteLine($"Export:");
        }
        else if ((int)obj < 0)
        {
            Console.WriteLine($"Import:");
        }

        Console.WriteLine($"ObjectIndex: {(int)obj}");
        Console.WriteLine($"Name: {obj.Name}");
        Console.WriteLine($"Class: {obj.Class?.Name}");
        Console.WriteLine($"Outer: {obj.Outer}");
        Console.WriteLine($"Path: {obj.GetReferencePath()}");
    }

If you're looking to modify the library for the sole purpose of modding UE Explorer, I recommend you to clone or fork this repository and install UE Explorer within your UELib/src/bin/Debug/ folder, or change the project's configuration to build inside of the UE Explorer's folder.

Compatible Games

This is a table of games that are confirmed to be compatible with the current state of UELib, the table is sorted by Package-Version.

Name	Engine:Branch	Package/Licensee	Support State
Unreal	100-226	61/000
Star Trek: The Next Generation: Klingon Honor Guard	219	61/000
X-COM: Alliance	200-220	61/000	Bad output at the start of functions (BeginFunctionToken)
Dr. Brain: Action Reaction	224	63-68/000
Nerf Arena Blast	225	63-68/000
The Wheel of Time	225:WoT	63-68/000
Unreal Mission Pack: Return to Na Pali	226b	68/000
Unreal Tournament	338-436	68-69/000
Deus Ex	400-436	68/000
Jazz Jackrabbit 3D	400	68/000
Duke Nukem Forever (2001)	613	68/002	UStruct offsets are off leading to bad output code
Rune	400	69/000
Unrealty	405	69/000
X-COM: Enforcer	420	69/000
Tactical Ops: Assault on Terror	436	69/000
Star Trek: Deep Space Nine: The Fallen	338	73/000
Harry Potter and the Sorcerer's Stone	436	76/000
Harry Potter and the Chamber of Secrets	433	79/000
Disney's Brother Bear	433	80/000	Link
Mobile Forces	436	81-83/000, 69
Clive Barker's Undying	420	72-85/000	Versions 72 to 83 are not auto detected.
Thief: Deadly Shadows	777:Flesh	95/133	LinkedData not supported
Deus Ex: Invisible War	777:Flesh	95/069	LinkedData not supported
XIII	829	100/058
Postal 2: Paradise Lost	1417	118/002
Tom Clancy's Splinter Cell	829	100/017
Tom Clancy's Splinter Cell: Double Agent	829	100/167:SCX	(PC) Offline mode version
Tom Clancy's Rainbow Six 3: Raven Shield	600-927	118/012-014
Unreal Tournament 2003	1077-2225	119/025
Devastation	600-?	118-120/004-008
Unreal II: The Awakening	829-2001	126/2609
Unreal II: eXpanded MultiPlayer	2226	126/000	Custom features are not decompiled
Land of the Dead: Road to Fiddler's Green	2226	126/001
Unreal Tournament 2004	3120-3369	128/029
America's Army 2	3339	128/032:033	2.5, 2.6, 2.8
America's Army (Arcade)	3339	128/032	2.6
Red Orchestra: Ostfront 41-45	3323-3369	128/029
Killing Floor	3369	128/029
Battle Territory: Battery	3369	128/029?
Vanguard: Saga of Heroes	Unknown	129/035
Harry Potter and the Prisoner of Azkaban	2226	129/000	Link
Shrek 2	2226	129
Shark Tale	2226	129/003
Lemony Snicket's A Series of Unfortunate Events	2226	129/003
Swat 4	2226:Vengeance	129/027
Stargate SG1: The Alliance	4180	130/004
Tribes: Vengeance	2226:Vengeance	130/027
Bioshock	2226:Vengeance	130-141/056
Men of Valor	926	137/000	PC
Bioshock 2	2226:Vengeance	143/059
Unreal Championship 2: Liandri Conflict	3323	151/002	Third-party
The Chronicles of Spellborn	3323	159/029
Duke Nukem Forever (2011)	Unknown	156/036	Extraction is required
Tom Clancy's EndWar	Unknown	329/000
Roboblitz	2306	369/006
Mass Effect (Xbox 360)	2674	391/092	Xenon
Medal of Honor: Airborne	2859	421/011
Frontlines: Fuel of War	2917	433/052
Army of Two	3004	445/079	Overall quality has not been verified
Mortal Kombat Komplete Edition	2605	472/046
Stargate Worlds	3004	486/007
Gears of War	3329	490/009
Mass Effect (Windows)	3240	491/1008(~112)	PC
Robert Ludlum's The Bourne Conspiracy		511/039
Transformers: War for Cybertron		511/144,145	PC, PS3, Xenon
Unreal Tournament 3	3809	512/000
Mirrors Edge	3716	536/043
Alpha Protocol	3857	539/091
APB: All Points Bulletin	3908	547/028-032
X-Men Origins: Wolverine	4206	568/101	Overall quality has not been verified
Gears of War 2	4638	575/000
CrimeCraft	4701	576/005
Batman: Arkham Asylum	4701	576/21
Medal of Honor (2010)	100075???	581/058	Bad byte-codes
Singularity	4869	584/126
MoonBase Alpha	4947	587/000
Saw	Unknown	584/003
The Exiled Realm of Arborea or TERA	4206	610/014
Monday Night Combat	5697	638/000
DC Universe Online	5859	638/6405
Unreal Development Kit	5860-12791	664-868
Blacklight: Tango Down	6165	673/002
Dungeons & Dragons: Daggerdale	6165	674/000
Dungeon Defenders	6262	678/002
Mass Effect 3 (Windows)	6383	684/194	PC (platform must be set to Console)
Mass Effect: Legendary Edition (Windows)	6383	684/171	PC (platform must be set to Console)
Alice Madness Returns	6760	690/000
The Ball	6699	706/000
Bioshock Infinite	6829	727/075
Bulletstorm	7052	742/029
Red Orchestra 2: Heroes of Stalingrad	7258	765/Unknown
Rising Storm 2: Vietnam	7258	765/771
Aliens: Colonial Marines	4170	787/047
Infinity Blade 1	7595	788/001	Console
Dishonored	9099	801/030
Tribes: Ascend	7748	805/Unknown
Tony Hawk's Pro Skater HD
Rock of Ages	7748	805/000
Batman: Arkham City	7748	805/101
Batman: Arkham Origins	7748	807/138	Not verified
Sanctum	7876	810/000
AntiChamber	7977	812/000
Waves	8171	813/000
Super Monday Night Combat	8364	820/000
Gears of War 3	8653	828/000
Quantum Conundrum	8623	832/32870
Borderlands	4871	Unknown
Borderlands 2	8623/0023	832/056
Borderlands: Game of the Year Enhanced	5001/0001	832/058
Remember Me	8623	832/021
The Haunted: Hells Reach	8788	841/000
Asura's Wrath	8788	841/000	-zlib; platform needs to be set to console.
Blacklight Retribution	8788-10499	841-864/002
Infinity Blade 2	9059	842-864/001	Console
Q.U.B.E	8916	845/000
DmC: Devil May Cry	8916	845/004
XCOM: Enemy Unknown	8916	845/059
Gears of War: Judgement	10566	846/000
Transformers: Fall of Cybertron	846(~587)/181
Deadpool	846(~587)/181
InMomentum	8980	848/000
Unmechanical	9249	852/000
Deadlight	9375	854/000
Land of the Dead	9375	854/000
Ravaged	9641	859/000
The Five Cores	9656	859/000
Painkiller HD	9953	860/000
Chivalry: Medieval Warfare	10246	860/000
Hawken	10681	860/004
Rocket League	10897	867/009 (868/032 has not been tested)	Decryption required
Styx: Master of Shadows	10499	860/004
Batman: Arkham Knight		863/32995	Not verified
Gigantic: Rampage Edition	19100	867/010
Infinity Blade 3		868/000	Console
Guilty Gear Xrd	10246	868/003	Decryption required
Outlast	12046	868/003
Might & Magic Heroes VII	12161	868/004	(Signature and custom features are not supported)
Bombshell	11767	870/000
Orcs Must Die! Unchained	20430	870/000
Gal*Gun: Double Peace	10897	871/000
Battleborn	8623/1055	874/078
A Hat in Time	12097	877-893/005
Blue Estate The Game	10246	893/000
Shadow Complex Remastered	10897	893/001
Soldier Front 2	6712	904/009
Rise of the Triad	10508	Unknown
Sherlock Holmes: Crimes and Punishments	10897	Unknown
Alien Rage	7255	Unknown

Beware, opening an unsupported package could crash your system! Make sure you have saved everything before opening any file!

Note UE3 production-ready packages are often compressed and must first be decompressed, Unreal Package Decompressor by Gildor is a tool that can decompress most packages for you; for some games you need a specialized decompressor, see for example RLUPKTool.

Want to add support for a game? See adding support for new Unreal classes

Do you know a game that is compatible but is not listed here? Click on the top right to edit this file!

How to contribute

• Open an issue
• Or make a pull-request by creating a fork of this repository, create a new branch and commit your changes to that particular branch, so that I can easily merge your changes.

Special thanks to

• Epic Games for UDN: Packages (general package format)
• Antonio Cordero Balcazar for UTPT (game support) and documentation (format)
• Dmitry Jemerov for unhood (early UE3 format)
• Konstantin Nosov for providing help and UE Viewer (game support)
• Contributors