uwdtool 1.4.1

The tool to pack and unpack UnityWebData 1.0 files

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UWDTool

A tool for extracting, packing, or inspecting the contents of data files used in Unity WebGL games, including assets and other related resources. Supports processing of *.unityweb files used in Unity 2019 and earlier versions.

What Is UnityWebData

A UnityWebData file is a file that is loaded and used in conjunction with a WebAssembly file in a WebGL game, primarily a file that combines all of the asset, resource, and metadata files.

Installation and Usage

Installation

[!NOTE] Python 3.9 or higher is required.

pip install uwdtool

CLI

uwdtool [-h] [-p | -u | -isp] [-i ARG_INPUT] [-o ARG_OUTPUT] [-c {brotli,gzip,none}]

• -h, --help: Displays help and information about the program.

• -p, --pack: Packs the files in the specified input directory into a UnityWebData file and saves it to the output path.
  The input should be the path to the folder containing the files to pack.

• -u, --unpack: Unpacks the specified UnityWebData file and saves the extracted files to the output directory.
  The input should be the path to the file to unpack, and the output should be the target folder for the extracted files.

• -isp, --inspect: Displays information about the contents of a UnityWebData file, including file names and sizes.
  Only the input file is required; the output path is not needed.

• -c: Specifies the compression format.
  Available options are brotli, gzip, or none.
  If omitted, the format is automatically detected.

What is a UnityWebData File?

A UnityWebData file is a bundled resource file used in Unity WebGL games, loaded alongside the WASM file. It typically contains assets, resources, and metadata packed into a single file.

In Unity versions 5.0 through 2019, these files used the .unityweb extension. Starting with later versions, the extension changed to .data. Unity supports compression formats like gzip and Brotli during the build process. Since 2019, the file extension itself (e.g., .data.gz or .data.br) indicates the compression format, making it easy to determine how to decompress it. However, in earlier versions, the .unityweb extension was used regardless of compression type, so the engine had to rely on markers inside the file to determine whether and how the data was compressed.

Importantly, once decompressed, the internal structure of a UnityWebData file is consistent regardless of its compression status.

UnityWebData Structure

Header

Name	Size (bytes)	Type	Description
Signature	16	string	Fixed string: "UnityWebData1.0\0"
File Table Offset	4	uint32	Offset to the start of the file data section (same as the first file's offset)

File Info Header

The following structure is repeated for each file, up until the file data section begins:

Name	Size (bytes)	Type	Description
File Offset	4	uint32	Offset to the start of the file
File Size	4	uint32	Size of the file in bytes
Filename Length	4	uint32	Length of the file name (n)
Filename	n	string	Name of the file

File Data Section

After the headers, all the actual file contents are stored sequentially.
To read a specific file, locate its offset and size from the header, then read the corresponding byte range from the data section.

Binary Template for 010 Editor

https://gist.github.com/akio7624/908497ef15a84a436fae9ab5439aa01f

This is a custom binary template for UnityWebData files, designed for use with 010 Editor's binary template system. It provides a visual representation of the internal structure, making it easier to analyze and understand the contents of a UnityWebData file.

If the data file is compressed, you must decompress it before analysis.