ATAK — Anomaly Texture Analysis Kit

Texture compression and backup utility for S.T.A.L.K.E.R. Anomaly modlists.

S.T.A.L.K.E.R. Anomaly and its modpacks represent a labor of love by hundreds of modders, culminating in a unique and memorable gaming experience. However, the ecosystem ships many texture assets uncompressed. On hardware with limited VRAM, this causes stuttering, hitching, and outright crashes during gameplay. ATAK compresses those textures to BCn block compression formats, dramatically reducing VRAM pressure with minimal visual difference.

Works with GAMMA, EFP, and any Anomaly-based modpack.

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Download

Grab the latest binary for your platform from Releases:

Platform	File
Linux x86-64	atak-vX.X.X-linux-x64.tar.gz
Windows x86-64	atak-vX.X.X-windows-x64.zip
macOS (Intel + Apple Silicon)	atak-vX.X.X-macos.tar.gz

No installation required.

Linux / macOS:

tar -xzf atak-vX.X.X-linux-x64.tar.gz
chmod +x atak-linux
./atak-linux

Windows: Extract the zip, run atak-windows.exe in Windows Terminal or PowerShell.

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First time? Start here.

ATAK defaults to Mod Output Mode — a non-destructive workflow that outputs compressed textures to a separate MO2 mod folder instead of modifying your originals. This is the recommended approach.

Setup:

1. Launch ATAK and go to Settings
2. Set your MO2 modlist.txt path
3. Set output mod name (default: ATAK)
4. Go to Backup Manager and create a backup — still recommended as a safety net
5. Go to Scan & Compress and press [r] to compress everything
6. Add the output folder (e.g. mods/ATAK/) as a mod in MO2
7. Place it at the top of your load order and enable it

To compress in-place instead (replaces original files — make a backup first): Disable Mod Output Mode in Settings. Then follow the backup-first workflow below.

In-place workflow:

1. Go to Backup Manager — create a backup first, always
2. Go to Scan & Compress
3. Press [m] to compress a single mod first — verify it looks right in game
4. If happy, press [r] to compress everything
5. If something looks wrong, restore from backup

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What it does

Backup & Restore

• Create compressed LZMA archives of your full Anomaly mods directory
• Restore individual mods or your entire modlist from backup
• Verify archive integrity

Mod Output Mode

Non-destructive compression that reads your MO2 modlist.txt to build a virtual filesystem — the same merged view MO2 presents to the game. Only the winning file for each texture path is compressed (respecting load order). Output goes to a single flat mod folder you add to MO2.

• Your original textures are never modified
• Incremental updates — rerun after adding mods, only new files are compressed
• Delete the output folder to force full recompression
• If scan shows 0 textures, check your modlist.txt path in Settings

Scan & Compress

ATAK scans for uncompressed DDS textures and classifies them by type using filename patterns and directory paths. Only textures explicitly matched by a profile are compressed — nothing is touched blindly.

Default profiles cover the most common texture categories:

Profile	Format	Detection method
Normal / bump maps	BC5	_bump, _normal, _nrm, _norm suffixes
Sights / Reticles	BC3	scope_reticles/, bonus_sights/, *crosshair*
UI / Icons	BC3	textures/ui/ path
Diffuse / color	BC3	_diff, _base, _col, _d suffixes
Weapon textures	BC3	textures/wpn/, textures/rwap/ paths
Character / hands	BC3	textures/act/, textures/MK/ paths
Sky textures	BC3	textures/sky/ path
Terrain / detail	BC3	textures/terrain/, textures/detail/ paths
Items	BC3	textures/items/, textures/item/, textures/usable_items/ paths
Particle / FX	BC3	textures/semitone/ path

Already-compressed textures (~24,000 in a typical Anomaly install) are detected and skipped automatically.

Unmatched textures are never touched. Files that don't match any profile are shown in scan results but excluded from compression. Add patterns to profiles.json to include them.

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Compression formats

ATAK uses BCn block compression — a GPU-native format that decompresses in hardware with no performance cost. The tradeoff is a small, usually imperceptible quality loss during the compression step.

Format	Field value	Alpha	Quality	Size	Linux GPU	Best for
BC1	BC1_UNORM	No	Good	0.5 bpt	Yes	Opaque diffuse, environment
BC3	BC3_UNORM	Yes	Good	1 bpt	Yes	UI, general alpha textures
BC5	BC5_UNORM	No	Excellent	1 bpt	Yes	Normal maps only
BC7	BC7_UNORM	Yes	Excellent	1 bpt	No (CPU)	High quality diffuse, weapons

bpt = bytes per texel

BC5 is required for normal maps — using BC3 on normal maps produces incorrect lighting. Do not change the Normal Maps profile format.

BC7 on Linux is CPU-only — no GPU acceleration available. Expect 40-60 minutes for large jobs. For faster Linux compression, use BC3 for all profiles (the default). Quality difference is minimal at normal viewing distances.

Mip chains: ATAK generates a full mip chain during compression using cubic filtering. This allows the engine to load lower-resolution versions of textures for distant objects, reducing effective VRAM usage further. Keep your in-game texture quality setting at High — lowering it on top of BCn compression will reduce visual quality unnecessarily.

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Configuration

Config lives at:

• Linux: ~/.config/atak/
• Windows: %AppData%\atak\
• macOS: ~/Library/Application Support/atak/

config.json

{
  "modsDir": "/path/to/Anomaly/mods",
  "backupDir": "/path/to/backups",
  "workerCount": 1,
  "backupThreads": 4,
  "backupLevel": 6,
  "scanExclusions": [".*", "downloads", "Downloads", "G.A.M.M.A. UI"],
  "modOutputMode": true,
  "modOutputName": "ATAK",
  "modlistPath": "/path/to/MO2/profiles/Default/modlist.txt"
}

• workerCount — concurrent texconv processes (compression only). Each worker pegs one CPU core. Default: 1
• backupThreads — 7-Zip thread count for backup/restore operations. Default: half your CPU threads
• backupLevel — 7-Zip compression level 1-9. Default: 6
• scanExclusions — directory names to skip during scan
• modOutputMode — non-destructive output mode. Default: true
• modOutputName — output mod folder name. Default: "ATAK"
• modlistPath — path to MO2 modlist.txt. Required when modOutputMode is true

Finding your modlist.txt:

• Usually at <MO2 install>/profiles/<Profile Name>/modlist.txt
• In MO2: click the profile dropdown → "Open Profile Folder"

profiles.json

Controls which textures get compressed and how. Created on first run from embedded defaults. Edit freely.

{
  "minFileSizeBytes": 1024,
  "excludePatterns": ["fx_sun*", "fx_*", "lut_*", "*#small*", "*cube#*"],
  "profiles": [
    {
      "name": "Normal Maps",
      "format": "BC5_UNORM",
      "generateMips": true,
      "maxTextureSize": 0,
      "patterns": ["*_bump.*", "*_normal.*"],
      "exclude": []
    }
  ]
}

Top-level fields:

• minFileSizeBytes — skip files smaller than this. Default: 1024
• excludePatterns — filename glob patterns never compressed regardless of profile match

Per-profile fields:

• name — display name in scan results
• format — compression format. See table above
• generateMips — generate full mip chain. true for most textures, false for UI
• maxTextureSize — cap output resolution. 0 = no limit. Set to 1024 on sky/terrain profiles for 4GB VRAM cards. Textures smaller than this value are never upscaled
• patterns — glob patterns matched against filename or full path
• exclude — optional per-profile exclusions

Pattern syntax:

• * matches any characters except /
• Patterns without / match filename only: *_bump.* matches rock_bump.dds
• Patterns with / match full path: */textures/wpn/* matches any file under textures/wpn/
• Matching is case-insensitive on all platforms
• Order matters — first match wins. Put specific patterns before general ones

Community profiles available in the profiles/ directory in the repository:

• default.json — conservative BC3 defaults (same as embedded)
• quality.json — BC7 for weapons and characters (Windows GPU recommended)

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Performance

Note on BC7: BC7 GPU acceleration is not available on Linux — CPU-only, ~40-60 min for large jobs. Windows benefits from DirectX GPU acceleration. For faster Linux compression, keep all profiles at BC3 (the default).

Benchmarks and feedback welcome — open a GitHub issue or post in the community Discord.

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Compression quality

Default profiles use BC3 for all textures except Normal Maps (BC5). BC3 produces minimal visible quality loss at typical Anomaly viewing distances and compresses quickly on all platforms.

For higher quality weapon and character textures, copy profiles/quality.json from the repository to your config directory — this uses BC7 for weapons and characters. Recommended for Windows users with GPU acceleration.

For 4GB VRAM cards, set "maxTextureSize": 1024 on Sky and Terrain profiles in profiles.json to reduce VRAM usage further beyond BCn compression.

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Known limitations

• BC7 GPU acceleration not available on Linux — CPU fallback, slow on large jobs
• Cancelling a compression job deletes the in-progress file — originals untouched
• 7-Zip backup progress is sparse on large solid archives — the archive is growing even when the progress bar appears stuck
• If the app crashes during backup/restore on Linux, run pkill 7zz if you notice high CPU/RAM usage afterwards
• Mod Output Mode without a valid modlist.txt will show 0 textures — check Settings if this happens

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Building from source

Requires Go 1.21+.

git clone https://github.com/noisethanks/atak
cd atak
go build -o atak-linux .

Release build:

CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build \
  -ldflags="-s -w -X main.version=v0.2.0" \
  -o atak-linux .

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GAMMA

S.T.A.L.K.E.R. GAMMA is a large modpack for S.T.A.L.K.E.R. Anomaly maintained by Grok. Join the community on Discord.

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Attributions

• texconv (Texconv-Custom-DLL) — MIT — matyalatte
• 7-Zip — LGPL v2.1 — Igor Pavlov
• Bubble Tea — MIT — Charmbracelet
• Bubbles — MIT — Charmbracelet
• Lip Gloss — MIT — Charmbracelet

Full license text available in-app via the About screen.

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Support

If ATAK saved your playthrough, consider supporting development:

noisethanks.com/support

Made by mrchocolate