mikunyan

Library to deserialize Unity AssetBundle files (*.unity3d) and asset files.

Installation

Add this line to your application's Gemfile:

gem 'mikunyan'

And then execute:

$ bundle

Or install it yourself as:

$ gem install mikunyan

If you want to install development build:

$ git clone https://github.com/Ishotihadus/mikunyan
$ cd mikunyan
$ bundle install
$ rake build
$ gem install -l pkg/mikunyan-3.9.x.gem

Usage

Basic Usage

require 'mikunyan'

# load AssetBundle
bundle = Mikunyan::AssetBundle.file(filename)

# you can load AssetBundle from blob
# bundle = Mikunyan::AssetBundle.load(blob)

# select asset (normaly only one asset)
asset = bundle.assets[0]

# or you can directly load asset
# asset = Mikunyan::Asset.file(filename)

# object list
list = asset.objects

# object PathIds
path_ids = asset.path_ids

# object container table (if available)
containers = asset.containers

# load object (Mikunyan::ObjectValue)
obj = asset.parse_object(path_ids[0])

# simplified structure (based on Hash)
obj_hash = asset.parse_object_simple(path_ids[0])

# hash can be easily serialized to json
require 'json'
obj_hash.to_json

Mikunyan::ObjectValue

Mikunyan::ObjectValue can be 3 types. Value, array and map.

# You can get whether obj is value or not
obj.value?

# get value
obj.value

# same as obj.value
obj[]


# You can get whether obj is array or not
obj.array?

# get array
obj.value

# you can directly access by index
obj[0]


# If obj is map, you can get keys
obj.keys

# get child object
obj[key]

# same as obj[key]
obj.key

Unpack Texture2D

You can get png file directly from Texture2D asset. Output object's class is ChunkyPNG::Image.

Some basic texture formats (1–5, 7, 9, 13–20, 22, 62, and 63), ETC_RGB4 (34), ETC2 (45, 47), and ASTC (48–59) are available.

require 'mikunyan/decoders'

# get some Texture2D asset
obj = asset.parse_object(path_ids[1])

# you can get Image object
img = Mikunyan::ImageDecoder.decode_object(obj)

# save it!
img.save('mikunyan.png')

Mikunyan cannot decode ASTC with HDR data. Use Mikunyan::ImageDecoder.create_astc_file instead.

Json / YAML Outputter

mikunyan-json is an executable command for converting unity3d to json.

$ mikunyan-json bundle.unity3d > bundle.json

Available options:

• --as-asset (-a): interpret input file as not AssetBudnle but Asset
• --pretty (-p): prettify output json
• --yaml (-y): YAML mode

Image Outputter

mikunyan-image is an executable command for unpacking images from unity3d.

$ mikunyan-image bundle.unity3d

The console log is json data of output textures as below.

[
    {
        "name": "bg_b",
        "width": 1024,
        "height": 1024,
        "path_id": -744818715421265689
    },
    {
        "name": "bg_a",
        "width": 1024,
        "height": 1024,
        "path_id": 5562124901460497987
    }
]

If the option --sprite specified, mikunyan-image will output sprites. The log json also contains sprite information.

[
    {
        "name": "bg_a",
        "width": 1024,
        "height": 1024,
        "path_id": 5562124901460497987,
        "sprites": [
            {
                "name": "bg_a_0",
                "x": 1.0,
                "y": 303.0,
                "width": 1022.0,
                "height": 720.0,
                "path_id": -7546240288260780845
            },
            {
                "name": "bg_a_1",
                "x": 1.0,
                "y": 1.0,
                "width": 720.0,
                "height": 258.0,
                "path_id": -5293490190204738553
            }
        ]
    },
    {
        "name": "bg_b",
        "width": 1024,
        "height": 1024,
        "path_id": -744818715421265689,
        "sprites": [
            {
                "name": "bg_b_1",
                "x": 1.0,
                "y": 1.0,
                "width": 720.0,
                "height": 258.0,
                "path_id": 4884595733995530103
            },
            {
                "name": "bg_b_0",
                "x": 1.0,
                "y": 303.0,
                "width": 1022.0,
                "height": 720.0,
                "path_id": 7736251300187116441
            }
        ]
    }
]

Available options:

• --as-asset (-a): interpret input file as not AssetBudnle but Asset
• --outputdir (-o): output directory (default is a basename of input file without an extention)
• --sprite (-s): output sprites instead of textures
• --pretty (-p): prettify output json

Dependencies

• json
• extlz4
• bin_utils
• chunky_png

Mikunyan uses oily_png instead of chunky_png if available.

FAQ

Sometimes unpacking fails

I'm sorry...

Can I unpack Mesh files?

It's hard work for me...

What mikunyan comes from?

Miku Maekawa.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/Ishotihadus/mikunyan.

License

The gem is available as open source under the terms of the MIT License.