Asset Store packages are collections of files and data from Unity projects, or elements of projects, which Unity compresses and stores in one file with the .unitypackage extension. Like a zip file, an Asset Store package maintains its original directory structure and metadata about assets (such as import settings and links to other assets) when it’s unpacked.
To get an Asset Store package from Unity or a third-party publisher, start by searching the Unity Asset Store to find assets that meet your needs. When you find an Asset Store package you want to use, buy or download it in the Asset Store. You can also make it easier to locate Asset Store packages by organizing your assets with labels and hiding deprecated or unused packages. Refer to hiding Asset Store packages.
In the Unity Package Manager, select the My Assets context to view your list of available Asset Store packages. You can search by name for Asset Store packages. When you find the Asset Store package you want to use, you can download and import it using the Package Manager window. If your Asset Store package has a newer version available, you can also update it directly in the Package Manager window.
Unity users can become publishers on the Asset Store, and sell the content they have created. Follow the instructions in Publishing to the Asset Store for creating a package draft and uploading your assets for publication on the Unity Asset Store.
プロジェクト内で Asset Store パッケージを管理するには、Package Manager ウィンドウを使用します。ただし、アセットファイルに直接アクセスする必要がある場合、Asset Store パッケージキャッシュで見つけることができます。このキャッシュは、グローバルキャッシュ とは別で、パッケージの再利用と共有をより効率的に行うことができます。Asset Store パッケージキャッシュは、以下のパスにあります (コンピューターの設定によっては隠しフォルダー内にある場合もあります)。
~/Library/Unity/Asset Store-5.x
C:\Users\accountName\AppData\Roaming\Unity\Asset Store-5.x
~/.local/share/unity3d/Asset Store-5.x
これらのフォルダーには、特定の Asset Store ベンダーに対応するサブフォルダーが含まれており、ダウンロードしてインポートした後に利用可能になります。Package Manager は、Asset Store パッケージパブリッシャーによって定義された構造体を使って、サブフォルダー内にアセットファイルを保存します。
You can override the default location of the Asset Store package cache root. For information, refer to Customize the Asset Store cache location.