Unity Addressables Per-Platform Group Settings

While developing a project for multiple platforms, we've encountered issues where the recommended packing settings for Addressable Groups differs, particularly when it comes to compression.  Some platforms don't natively compress the final package, so it's useful to compress the Addressable packed assets to keep the overall file size down.  Other platforms have recommended packing settings to help with patching.  In some cases, having uncompressed Addressable packed assets is ideal for patching.  There's currently no way of specifying different packing settings per platform (as of Unity Addressables 1.19.19).  Unity is aware of the need for this, but we have not seen any public progress on it.

In the mean time, we've come up with a relatively straightforward way to handle this situation so that we don't have to manually change settings when switching platforms.  In short, we have a new Addressable Group schema to apply where we can specify overrides for particular packing settings per platform, and a new Addressables build script that looks for this schema and replaces the actual packed schema with the overrides, if appropriate.

The code is available here.

In addition to the code, there are several more manual steps that need to be taken before things become fully automated.

1. Create a new PlatformBuildScriptPackedMode Addressable Data Builder and (ideally) place it in Assets/AddressableAssetsData/DataBuilders.
   
2. Register this new Addressable Data Builder with the Addressables Settings.  In your Addressable Asset Settings, add the new PlatformBuildScriptPackedMode asset to the list of "Build and Play Mode Scripts".

   

   
   
3. Now go to individual Addressable Groups and add the new PlatformBundledAssetGroupSchema to each Group that needs an override.

   

   
   
4. To actually build correctly, you need to select the new Platform Build Script Packed Mode builder from the Addressables build menu.

   

   
   

This should cover all the basics for using the platform overrides.  If you want to automate builds and select the proper builder, we recommend following this example from Unity.

You can add more platforms as needed when you use the code, as well as more overrides for your specific use case.  Right now, this schema does not support multi-editing, though that would be a very useful feature for future development.