UBT | Unity Bundle Tool

[Masquerade]

UBT | Unity Bundle Tool

Unity Bundle Tool is a software made by my friend, SowwyItsAnAlt, which I have been using in my repacks for a few months. With her permission, I have rewritten and polished the code and made a new executable which I am sharing here.

The function of this tool is the ability to decompress compressed Unity Asset Bundles and then recompress them to a close enough point in which a patch is possible (& viable!). I like to use HDiffZ because it gives the smallest patches. XDelta should work just fine (patch creation is significantly quicker than with HDiffZ although the patch file will be larger).

UBT is based on AssetTools.NET by nesrak1 and has compression support for both LZ4 and LZMA algorithms.

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 Usage: UBT.EXE <options> <infile> <outfile>

 Options:

     -i       : List information about bundle file (only specify <infile>).
     -d       : Decompress bundle file.
     -c       : Compress bundle file (must specifiy use of LZ4 or LZMA).
     -credits : View credits.

 Example usage:

 UBT.EXE -i data.unity3d
 UBT.EXE -d data.unity3d decompressed_data.unity3d
 UBT.EXE -c lz4 decompressed_data.unity3d data.unity3d
 UBT.EXE -c lzma decompressed_data.unity3d data.unity3d

To prove just how well this tool works, I will demonstrate on the game "Poly Bridge 2" (which I do recommend you all try if you enjoy a good puzzle like myself). This game contains "data.unity3d" which is compressed with LZ4. The steps are:

1. Decompress the bundle
2. Compress the decompressed file using the same compression algo as what the original bundle was compressed with
3. Use your patch program of choice to create a patch file between the new compressed file and the original compressed bundle.
   
   
   
   As we can see from the above image, the new file is so similar that our HDiffZ patch is less than 1mb in size! Now, in your repack installation, you simply include the decompressed file and compress it then patch it using the patch file after the archive is extracted. Easy!
   
   Of course, you don't need to patch the file, since Unity will read the file regardless - compressed or decompressed. The patch is simply for a 100% CRC perfect repack.
   
   Highlighted above is the function of the -d and -c option. Using -i will give the file size in bytes, MD5 and compression type used on the input file.
   
   This is a standalone tool and NOT for use with FreeArc.

[Masquerade]

Update for 10/2/22

• UBT now works with bundles larger than 2GB.
• AssetsTools.NET library upgraded from v2.0.9 to v2.0.11.
• Significantly less memory usage for compression and decompression.

• Please note that YMMV for patches with larger bundles...
  
  
  
  
• The above image shows a test on SKUL: The Hero Slayer.

[Masquerade]

*.CMS from Car Mechanic Simulator games are compressed Asset Bundles with LZ4, however devs changed the File Header so that the "U" in UnityFS is replaced with an S.

If you swap the S for a U, you can then decompress the bundles with UBT

[L0v3craft]

Hi. Thank you very much for your work, but please, share an UBT.exe file that works with files larger than 2GB and that is not detected as a trojan. It is dected as virus by 44 on 67 antiviruses:

https://www.virustotal.com/gui/file/9d34b1c2b139f41d6c733b3cb0730ec76c70a6083818c4ee28644ed5421a365f/detection

it is useless for repacks if the antivirus of the user deletes or blocks it.

Edit: testing it on the file data.unity3d from the game "TUNIC" and gives error in re-compression.

[Masquerade]

Unprotected version: https://bayfiles.com/77eaG3Scxc/UBT_7z

Compiled + ILRepack

[-tara]

ran decomp on "data.unity3d" on a game called "Mango", the file is ~1.7 GB and is compressed with lz4, got an output of ~4 GB or so. Then compressed it using lz4 and the tool finished weirdly quick, after checking the output of the compression it was 300 Megs, then i tried running the game using this output as the "data.unity3d" and the game ran however every texture was purple, whats going on?

[Joe Forster/STA]

Originally Posted by -tara

however every texture was purple

Just an idea: this purple is the transparent color in the textures but the compressor forgot to keep the transparency flag.

[Masquerade]

Update for 15/7/22

• AssetsTools.NET library upgraded from v2.0.11 to v2.0.12.
• AssetsTools.NET library made external to the executable.

What this means is that you can now update the library without needing a compiled executable. Useful for any future updates from nesrak1.

Download the latest build from the AssetsTools.NET GitHub and grab the file "AssetsTools.NET.dll" from the zip. Put it in the same folder as UBT.EXE and you're good to go. I don't mind compiling a "standalone" version with the library merged into the executable if someone would like that.

https://github.com/nesrak1/AssetsToo...eleases/latest

Also there's no support for Powerwash Simulator because the bundles are strange. Here's a quote from sowwyitsnalt when we were discussing the bundles:

Originally Posted by sowwyitsanalt

The bundles themselves seem to be broken, maybe by the devs, basically what happens is the bundle has a size of 16735030, but it reports the data starts at 1487 and is of length 16735288 so it would end after the actual bundle

[dixen]

Batch decompress - it possible?

[Masquerade]

Originally Posted by dixen

Batch decompress - it possible?

For batch file:

for /r %%f in (*.bundle) do ubt -d "%%f" "%%f.dec"

Or in parallel, use mparallel tool:

for /r %%f in (*.bundle) do echo ubt -d "%%f" "%%f.dec" >> run.txt

mparallel --input=run.txt

[dixen]

As Dusk Falls

UBT.exe - c lz4 1.tmp 2 tmp - don't work and don't compressed

UBT.exe - c lzma 1.tmp 2 tmp - all fine works.

[Masquerade]

Originally Posted by dixen

As Dusk Falls

UBT.exe - c lz4 1.tmp 2 tmp - don't work and don't compressed

Please may you upload a small sample?

[dixen]

Originally Posted by Masquerade

Please may you upload a small sample?

https://drive.google.com/file/d/1tYe...ew?usp=sharing

Old version (UBT_Unprotected) - All fine with lz4

[KaktoR]

Originally Posted by Masquerade

Unprotected version: https://bayfiles.com/77eaG3Scxc/UBT_7z

Compiled + ILRepack

Could you reupload the unprotected version? I get "Bad Gateway" on this download.

[Hexagon123]

Originally Posted by KaktoR

Could you reupload the unprotected version? I get "Bad Gateway" on this download.

Here.