unity-texture-toolkit
Unity Texture Toolkit
written in PHP
What’s this for
I wrote this for automatic game resource updating and dumping to png/webp, it’s currently deployed on my server
https://redive.estertion.win/
Main codes are highly inspired by AssetStudio
Requirement
php-ext-lz4 ( For decompressing the bundle )
astcenc ( For decompressing ASTC texture format )
ffmpeg ( For reencoding )
astcenc
and ffmepg
need to be placed under PATH, like /usr/bin
(cron may not search for /usr/local/bin
, or you can configure it)
Limitation
Current supported format:
- ASTC compressed 2d image
- Raw rgb ( e.g. RGB24 RGB565 RGBA4444 etc )
I’ve only met these formats so far
How to use
require_once 'UnityAsset.php'; // This will require UnityBundle.php as it needs FileStream $bundleFileName = 'bundle_name.unity3d'; // This is the bundle file with file header "UnityFS" $bundleFileStream = new FileStream($bundleFileName); // Create a read stream $assetsList = extractBundle($bundleFileStream); // This will extract assets to disk unset($bundleFileStream); // Free the handle foreach ($assetsList as $asset) { if (substr($asset, -4,4) == '.resS') continue; // .resS file is external data storage file $asset = new AssetFile($asset); foreach ($asset->preloadTable as &$item) { if ($item->typeString == 'Texture2D') { $item = new Texture2D($item, true); // Parse and read data $item->exportTo($item->name, 'webp', '-lossless 1'); // export to format, with additional encode parameters // $item->exportTo($item->name, 'png'); unset($item); // Free up memory } } $asset->__desctruct(); unset($asset); // Free up memory } foreach ($assetsList as $asset) { unlink($asset); // clean up files }
What’s in the sub directory
These are the files I’m croning on my server for automatic update
There are different versions, as I wrote the Princess Connect Re:dive
first, its code has least feature, and cgss
is the current latest
They all share the same UnityBundle.php
Implementation detail
- UnityBundle.php
class FileStream($filename)
and MemoryStream($data)
:
Two similar stream reader, FileStream accepts filename, MemoryStream accepts string as binary.
Reading value can perform either function $stream->readInt32()
or property $stream->ulong
Property position
can get current and set to seek point
Property littleEndian
determine either use little endian reading or not
Function write($newData)
will always write to the end for MemoryStream, but can overwrite current data position for FileStream
function extractBundle($bundleStream)
:
Accepts a stream, may throw exception if is invalid file, or chunk is LZMA compressed, or something wrong happened
Returns a list of asset file names extracted
- UnityAsset.php
class AssetFile($assetFileName)
:
Accepts a filename, may throw exception if something is not supported
Can get resource info through property preloadTable
class Texture2D($preloadData, $readSwitch = false)
:
Accepts an AssetPreloadData
item from preloadTable
, may throw an exception if format not supported
Second parameter determine weither read data or not, if you only want to get the information
Can call member function exportTo($saveTo, $format="png", $extraEncodeParam = '')
to export supported texture