NRS Asset Manager

A Python toolkit for extracting and parsing game assets from NetherRealm Studios titles — UE3-based Midway engine games and UE4.27 (MK1).

Supported Games

Game	Codename	Engine	Compression	External Data	Status
Mortal Kombat X (2015)	MK10	UE3 (677)	ZLIB / LZO	.tfc	Full extraction + 3D mesh + FMOD audio
Injustice 2 (2017)	DCF2	UE3 (732)	Oodle v4	.tfc	Full extraction + skeletal mesh
Mortal Kombat 11 (2019)	MK11	UE3 (769)	Oodle v5	.psf	Full extraction
Mortal Kombat 1 (2023)	MK12	UE4.27	Oodle v9	.ucas (IoStore)	UAsset parsing + IoStore extraction

Quick Start

CLI

# Auto-detects game from file header and version
python main.py extract path/to/file.xxx

# Display file header
python main.py header path/to/file.xxx

# List exports, imports, or names
python main.py list path/to/file.xxx --exports

# VFS mount and browse
python main.py vfs mount path/to/directory/
python main.py vfs tree path/to/file.xxx --depth 3

Browser (GUI)

python -m gui.browser

The PyQt6 browser supports:

• Load tab — Add game paths, scan files, mount .xxx/.uasset/.utoc files with background threading
• Browse tab — Tree with per-section texture preview, 3D mesh viewer, DataTable JSON, material sphere preview
• Coalesced tab — Folder tree for localization/config files with export
• MKScript tab — MKO function/variable/asset viewer

Extraction Pipeline

UE3 Games (MKX, IJ2, MK11)

.xxx (Compressed Archive)
  → Midway Format (Decompressed UPK)
    → Exports (Game Objects)
      → Handlers (Database→JSON, Texture2D→DDS/PNG, SkeletalMesh→3D, etc.)

UE4 Games (MK1)

UTOC/UCAS (IoStore, AES-ECB + Oodle v9)
  → .uasset (Midway equivalent)
    → Exports (DataTable→JSON, etc.)

See Extraction Pipeline for details.

Encryption

Format	Algorithm	Games
Coalesced	AES-ECB	MKX, IJ2, MK11
DFP	Rolling XOR + custom stream cipher	MK11
FSB (FMOD)	Bit-reverse + XOR	MKX
IoStore	AES-256-ECB	MK1

Project Structure

mk_utils/
├── nrs/
│   ├── ue3_common.py              # Shared UE3 base classes
│   ├── scene_assembler.py         # Mesh → material → texture binding
│   ├── vfs/                       # Virtual filesystem (mount, browse, cache)
│   ├── mkscript/                  # MKO bytecode parser (MKX, IJ2, MK11)
│   ├── mkx/                      # MKX game module (UE3)
│   ├── ij2/                      # IJ2 game module (UE3)
│   ├── mk11/                     # MK11 game module (UE3)
│   └── mk1/                      # MK1 game module (UE4.27)
│       ├── ue4_common.py          # UAsset structs
│       ├── archive.py             # IoStore container (UTOC/UCAS)
│       ├── midway.py              # UAsset parser
│       ├── ue4_properties.py      # UE4 tagged property deserializer
│       └── class_handlers/        # DataTable handler
├── formats/
│   ├── compression/               # Oodle, ZLIB, LZO
│   ├── coalesced.py               # AES-ECB Coalesced decryption
│   ├── dfp.py                     # DFP encryption (pure Python)
│   ├── fsb.py                     # FSB audio decryption
│   └── dds.py                     # DDS header building + PNG conversion
├── utils/
│   └── structs.py                 # ctypes binary struct wrapper
gui/
├── browser.py                     # PyQt6 asset browser
├── mesh_viewer.py                 # OpenGL 3D mesh viewer
└── file_detector.py               # Magic/FourCC-based file detection

Documentation

• Architecture: Extraction Pipeline · File Format Overview · How to Expand
• Game Formats: Injustice 2 Format · MKX Format · MK11 Format · MK1 Format · Format Comparison
• Game Knowledge:
  • IJ2: IJ2 Inventory System · IJ2 Gear Randomization
  • MKX: MKX Rendering and Materials · MKX Audio
  • MK11: MK11 Encryption and VFS
  • MK1: MK1 IoStore and DataTable
• Handlers: Database Handler · Texture2D Handler
• Reference: UE3 Property Types · Enums Reference · Known Limitations