Which cooking rules prevent editor-only assets from appearing in Shipping builds?

Asset Inclusion Rules for Shipping Builds

In Unreal Engine 5, the primary mechanism preventing editor-only assets from appearing in Shipping builds is the Reachability Analysis performed during the cook process. By default, the cooker only includes assets that are hard-referenced by the maps listed in the List of maps to include in a packaged build setting. Assets marked as "Editor Only" or those residing in editor-specific folders are stripped regardless of references.

Configuration for Dynamic Asset Inclusion

When assets are referenced dynamically (via soft references or string paths), they are not discovered by the standard reachability pass. To ensure these are flagged for inclusion, you must use the Asset Manager. The following configurations determine inclusion:

• Primary Asset Labels: These act as explicit overrides. By assigning a Primary Asset Label to an asset or folder, you tell the cooker to include those assets regardless of whether a map references them.
• Primary Asset Types: Defined in Project Settings > Asset Manager, these allow the engine to scan specific paths for specific classes (e.g., UDataAsset) and treat them as primary assets to be cooked.
• Additional Asset Directories to Cook: A broader setting in Packaging options that forces the inclusion of entire directories, though this is less granular than the Asset Manager.

Primary Asset Labels vs. Reachability

Yes, Primary Asset Labels consistently override default reachability rules. While a soft reference alone is insufficient to trigger a cook, a Primary Asset Label explicitly flags the asset for the Asset Manager to track and package. This ensures that LoadObject or AsyncLoad calls succeed in a Shipping build.

Verification Steps

To verify if your assets are being correctly excluded or included, use these scoped checks:

1. Check Packaging Settings: Navigate to Project Settings > Project > Packaging and verify the List of maps to include in a packaged build is populated.
2. Validate Asset Manager: Ensure your custom asset types are registered under Project Settings > Asset Manager.
3. Inspect Cooked Content: After packaging, browse the Saved/Cooked/[Platform] folder. If an asset is missing from this directory, it was stripped during the cook process.

Diagnostic Note: Are you using a custom UAssetManager subclass to handle the loading logic, or are you relying on the default engine implementation?