Load content from multiple projects
If you're working with multiple projects, such as a large project broken up across multiple Unity projects, you can use Addressables.LoadContentCatalogAsync to link together code and content across the various projects.
Set up multiple projects
To create a multi-project setup make sure of the following:
- Each project uses the same version of the Unity Editor.
- Each project uses the same version of the Addressables package.
Projects can contain whatever assets and code you need for your given situation. One of your projects must be your main or source project. This is the project that you build and deploy game binaries from. Typically, this source project contains code and little to no content. The main piece of content in the primary project is a bootstrap scene at minimum. You might want to include any scenes that need to be local for performance purposes before any AssetBundles are downloaded and cached.
Secondary projects are the opposite and contain content and little to no code. These projects need to have remote Addressable groups and Build Remote Catalog enabled. Any local data built into these projects can't be loaded in your source project's application. Non-critical scenes can be in these projects and be downloaded by the primary project when requested.
Load assets from multiple projects
Once you have your projects setup, the workflow generally is as follows:
- Build remote content for all secondary projects.
- Build Addressables content for source project.
- Start the source project's Play mode, or build the source project's binaries.
- In the source project, use
Addressables.LoadContentCatalogAsyncto load the remote catalogs of the other projects. - Proceed with game runtime as normal. Now that the catalogs are loaded, Addressables can load assets from any of these locations.
It might be worth having a minimal amount of content built locally in the source project. Each project is unique, and has unique needs, but having a small set of content needed to run your application in the event of internet connection issues or other various problems is advisable.
Handle built in resources and shaders
Addressables builds a Unity built-in resource AssetBundle for each set of Addressables player data that gets built. This means that when multiple AssetBundles are loaded that were built in secondary projects, there might be multiple built in AssetBundles loaded at the same time.
Depending on your specific situation, you might need to use the Built In Bundle Naming Prefix on the AddressableAssetSettings object. Each built in AssetBundle needs to a different name from others built in your other projects. If they're not named differently Unity displays the The AssetBundle [bundle] can't be loaded because another AssetBundle with the same files is already loaded. error.