Cyberpunk 2077 (REDEngine 4 / REDengine v4) — Archives, Models, Textures & Audio

Source: XeNTaX forum knowledge extraction (2020–2023). Covers .archive (RDAR+KARK), Oodle compression, .mesh/.buffer/.rig/.morphtarget model stack, .xbm/.mi textures, Wwise .wem/.opuspak/.bnk audio, and tools. Shares REDEngine lineage with The Witcher 3 (see Witcher 3 doc); CP2077 runs on REDengine 4.

1. Container Format: `.archive` (RDAR + KARK)

Game data packed in .archive files with RDAR magic (version 12).

struct Header {
 char RDAR[4];
 int version; // 12
 int64 fileSystemOffset;
 int64 fileSystemSize;
 int64 unk2; // 0
 int64 fileSize;
 int unk3[33]; // 0
};

struct FileSystem {
 int unk1; // 8
 int chunkSize;
 int64 unk2;
 int numDataChunkGroups;
 int numDataChunks;
 int numUnk3;
 DataChunkGroup dataChunkGroup[numDataChunkGroups];
 DataChunk dataChunk[numDataChunks];
 int64 unk3[numUnk3];
};

Oodle Compression

Compressed entries begin with KARK magic
Decompressed via Oodle (requires game's oo2core_<version>_win64.dll or oo2ext_7_win64.dll)
QuickBMS script (cyberpunk_2077.bms, aluigi) uses comtype oodle
OodleSharp wrapper (github.com/Crauzer/OodleSharp) for C# integration
rfuzzo's KAITAI spec (.ksy) available

Filenames Are Hashed

Filenames stored as hashes (like Watch Dogs, Hitman, RE Engine)
Tools must hook filenames or ship hash→name dictionary
eprilx: ~600k known, ~50k missing
Ekey: 1.3M hashes mapped across archives (e.g., basegame_3_nightcity.archive 99%, lang_en_text.archive 100%)
Merged into WolvenKit/CP77Tools

2. Extraction Tools

Tool	Purpose	Notes
QuickBMS `cyberpunk_2077.bms`	Extract `.archives` → `.dat`	aluigi; Oodle decode via `comtype oodle`
CP77Tools (rfuzzo)	Extract with correct names/paths; decompress; rebuild	github.com/rfuzzo/CP77Tools; needs `oo2ext_7_win64.dll`; `uncook`/`unbundle`/`rebuild`
Wolven-kit (Traderain)	CDPR modding toolkit	github.com/Traderain/Wolven-kit; CP2077 support added
CR2WTools / cr2w.dll	CR2W file viewer	W3 `cr2w.dll` in Wolven-kit; classes outdated for CP2077

CP77Tools: `uncook` vs `unbundle`

Unbundle — extracts .mesh files, but mesh data stays hidden in Oodle-compressed blocks within .mesh. Noesis cannot preview without data.
Uncook — decompresses data into separate .buffer files (Noesis needs these). Requires game's Oodle DLL.

uncook -p "D:\GOG\Cyberpunk2077\...\basegame_4_gamedata.archive" -w *mesh*

Some meshes need --forcebuffers to get buffers
CP77Tools v1.0+ stopped producing buffer files, breaking older Noesis scripts
Use CP77Tools 0.2.0.1 for buffer files with older fmt_mesh Noesis script

3. Models: `.mesh`, `.buffer`, `.rig`, `.morphtarget`

File Stack

Extension	Description
`.mesh`	CR2W mesh definition (external data refs + file links)
`.buffer` / `.mesh.N.buffer`	Oodle-decompressed vertex/index data blocks. Noesis auto-loads if same base name in same folder
`.rig`	Skeleton/bone hierarchy data
`.morphtarget`	Facial morph targets (character customization), under `basegame_4_gamedata\base\characters\head\player_base_heads\`
`.mi`	Material instance
`.mt`/`.ml*`	Material/layer files
`.dat`	Raw QuickBMS output — needs decryption/decompression (CP77Tools handles)

Noesis Plugin: `fmt_CP77mesh.py`

Original: Joschka + akderebur
Expanded: alphaZ (v1.4+)

Supported Import (v1.1–1.2.x)

Positions (scaled correctly), UVs, normals, bone indices/weights, bones + names, full skeleton via .rig

alphaZ Additions (v1.4x)

Textures: preview .xbm and .mi (incl. multi-image); rename embedded to .cp77tex; beta export as .buffer
Model import: upright rotation + user scale (default 100×), corrected bone maps via .rig, rotated normals, .morphtarget support, double-sided hair splitting, vertex colors, tangents, damage/garment meshes
Model export: FBX → .mesh, new data to .mesh.buffer; -bones (bone pos only), -meshbones (bones + model)
Rebuild for in-game:

rebuild -p "MODDED FOLDER PATH" -b -t --keep --unsaferaw

Key Options (top of `.py`)

meshScale = 100, bHighestLODOnly, bLoadRigFile/bAutoDetectRig, bParentToRootIfNoParent, bReadTangents, bImportMorphtargets, bVertexColors, bFlipImage

Noesis Troubleshooting

Symptom	Fix
"Wrong buffer file" / can't preview/export	Uncook (not just unbundle); keep `.buffer` next to `.mesh`
Rig rejected as invalid	Mesh uses multiple `.rig` files; enable `bLoadSeveralRigFiles`
Textures same name	Patch script to load `<meshname>_d01.dds` / `*_n01`
UVs dead/messed up	Open issue; weapons/vehicles/hair OK, clothes/characters often broken
Normal maps wrong on FBX	Engine flips green channel; invert/flip green channel
Bone weights off by one	Reported on some models (iguana)
Morphtarget FBX export	Blend-shape export broken/disabled in script; workarounds on Discord

Character Assembly

Characters assembled from many meshes scattered across archives — no single mesh
Dig through appearance / cookedappearance files to find meshes
3D map data: base\entities\cameras\3dmap\3dmap_* (gamedata archive)

4. Textures: `.xbm` / `.mi` / Atlas Masks

Extracted via CP77Tools → .png/.dds named: *_d01 (diffuse), *_n01 (normal), *_rm01 (rough/metal), *_maskset (channel masks: specular/AO/metallic packed RGB)
Normal maps often no blue channel (only RG) — expected, not a bug
Texture atlases with tile-masks: clothes/weapons use mask-packed atlases, not direct diffuse. Black 16×16 tiles removed to save space; must reconstruct from tiles buffer + CR2W definition JSON + atlas buffer (unsolved on forum)
Repacking originally unsupported; CP77Tools added pack/rebuild but repacking without uncooking crashed game
CDPR later released official modding toolkit for unpacking/packing textures

5. Audio: Wwise `.wem`, `.opuspak`, `.bnk`

CP2077 audio is Wwise. Banks in .archive files (audio_2_soundbanks.archive, etc.) → extracted as .bin/.wem.

`.wem` Variants (v1.04)

Format Tag	Type	Decode With
`0x0001`	PCM	WEMConverter / vgmstream (rename `.bin`→`.wem`)
`0xFFFE`	WAVE_EXTENSIBLE PCM	WEMConverter
`0xFFFF`	Ogg Vorbis (non-standard)	ww2ogg

Opus Detection

Some files have RIFF/wav header + PCM tag but actually Opus data
Detect: hex 4F 67 67 53 ("OggS") at offset 0x2C
Strip everything before to make valid .opus
Python script shared to split soundbanks → named .opus files

`.opuspak` — Opus Sound Archives

In soundbanks; OpusUnpack (ninearts, .NET) extracts to playable .wem (foobar2000 + vgmstream)

`.bnk` — Wwise Sound Banks (Car Sounds)

New Wwise variation — Wwise Extractor, bnkextr/ww2ogg/revorb, vgmstream fail (only garbled engine noise via IMA codecs)

Video

.bk2 (Bink) → Rad Video Tools

6. Game Data / Localization

Text in lang_*_text.archive (e.g., lang_en_text.archive = 3,222/3,222 = 100% named)
basegame_4_gamedata.archive = gameplay/gamedata (76,536/120,287 = 63% named at time)
DRM-free on GOG (GOG preload used for early RE)
CDPR confirmed official modding tools post-release

7. Tools Reference

Tool	Purpose	Notes
QuickBMS `cyberpunk_2077.bms`	Extract `.archives`	aluigi; Oodle via `comtype oodle`
CP77Tools	Extract/decompress/rebuild	rfuzzo; needs `oo2ext_7_win64.dll`; uncook/unbundle/rebuild
Wolven-kit	CDPR modding toolkit	Traderain; merged hash→name list
fmt_CP77mesh.py (Noesis)	Import/export mesh/rig/morph	alphaZ; needs uncooked `.buffer` files
OodleSharp	Oodle decompress wrapper	github.com/Crauzer/OodleSharp
ww2ogg	Vorbis WEM → OGG	hcs64
WEMConverter / vgmstream	PCM WEM decode/play	vgmstream also plays `.opuspak` output
OpusUnpack (ninearts)	`.opuspak` → `.wem`	.NET console tool
Rad Video Tools	Play `.bk2` video	Bink
ww2ogg/revorb/bnkextr/Wwise Extractor	`.bnk` decoding	FAIL on CP2077's new Wwise variation

8. Community Resources

Resource	What it is	Notes
Modding.wiki — Cyberpunk 2077	Community knowledge base (Nexus Mods)	General modding guidance; format specs stay in the sections above

Key Facts

Archives: .archive (RDAR magic) + Oodle (KARK) + hashed filenames
Models: .mesh (CR2W) + .buffer (vertex data, needs uncook) + .rig (skeleton) + .morphtarget
Textures: .xbm/.mi (CR2W-wrapped DDS), atlases with tile-masks (unsolved), normal maps RG-only
Audio: Wwise — PCM/WAVE_EXT/Vorbis/Opus .wem, .opuspak, .bnk (new variation, undecoded)
Modding: CP77Tools (extract/rebuild), Wolven-kit (toolkit), fmt_CP77mesh (Noesis), official toolkit later
Hash→name dict critical (1.3M+ mapped, merged into tools)

1. Container Format: .archive (RDAR + KARK)​

Header & Filesystem (IceReaper's 010 template)​

Oodle Compression​

Filenames Are Hashed​

2. Extraction Tools​

CP77Tools: uncook vs unbundle​

3. Models: .mesh, .buffer, .rig, .morphtarget​

File Stack​

Noesis Plugin: fmt_CP77mesh.py​

Supported Import (v1.1–1.2.x)​

alphaZ Additions (v1.4x)​

Key Options (top of .py)​

Noesis Troubleshooting​

Character Assembly​

4. Textures: .xbm / .mi / Atlas Masks​

5. Audio: Wwise .wem, .opuspak, .bnk​

.wem Variants (v1.04)​

Opus Detection​

.opuspak — Opus Sound Archives​

.bnk — Wwise Sound Banks (Car Sounds)​

Video​

6. Game Data / Localization​

7. Tools Reference​

8. Community Resources​

Key Facts​