Deprecation Notice: Legacy Asset IDs

[AMZN-Gene]

Deprecated APIs

void AssetRegistry::RegisterLegacyAssetMapping(const AZ::Data::AssetId& legacyId, const AZ::Data::AssetId& newId);

void AssetRegistry::UnregisterLegacyAssetMappingsForAsset(const AZ::Data::AssetId& id);

AZ::Data::AssetId AssetRegistry::GetAssetIdByLegacyAssetId(const AZ::Data::AssetId& legacyAssetId) const;

LegacyAssetIdToRealAssetIdMap AssetRegistry::GetLegacyMappingSubsetFromRealIds(const AZStd::vector<AZ::Data::AssetId>& realIds) const;

Alternatives APIs

There aren't any alternative APIs, rather, users should recreate the legacy assets in order to generate a new asset id. Also be sure to update any components which reference that asset.
Any projects started in O3DE should already be in the clear; they are using modern asset ids. For projects started in Lumberyard and converted to O3DE, developers can run their game and look out for legacy asset warnings printed to the log. Search for "Deprecated asset id warning!"

Last Release

Tentatively the next release stabilization/2410

Additional Context

"Legacy" UUIDs date back to the Lumberyard days (prior to O3DE's existence in 2021). Each asset's legacy-type uuid is stored and so grows linearly as games add more assets. This results in a doubling of the storage size requirements for bookkeeping assets (storing the modern asset id and then a fallback legacy asset id).
While a single UUID leaves a small memory footprint, keep in mind, source and product assets (the assets that end up being generated in the cache folder) are not 1-to-1. A single source asset can result in generating many game-ready product assets. For example, it's common for a project with 30,000 assets, to end up with 100,000+ product assets.