hzFishy's Game Dev Notes

Asset Manager & Data Assets

Latest update: Aug 15, 2026

Asset Manager

Danger of LoadSynchronous

Example of why LoadSynchronous is very bad and shouldn’t be used in shipped builds (Thanks to Northstar and Jambax)

Northstar

“Let’s say you’re loading a map async. It’s a big map and it’s taking a while. Then you call LoadSynchronous on a DA or something. Map load gets cancelled, DA blocks game thread to load, Map starts loading all over again but blocking the game thread”

In other words: “LoadSynchronous halts all requests in the queue. They can’t resume async so SM handles this by sync loading them” So LoadSynchronous flushes the entire streaming queue. Which means that it will sync load anything that was running async, then it will load the object you requested.

But FStreamableManager::RequestSyncLoad isn’t exactly the same:

  • if you call RequestSyncLoad and other async requests have higher priority, nothing is flushed*
  • *StreamableManager also does other things like check if assets are already being load via another request etc, blocking on that request instead. So if you’ve already loaded something async as part of a batch, then want to load an item sync anyway - the entire batch will be “flushed” and waited on

Asset Manager

Thanks to Ramius LoadPrimaryAssets returns the stream handle for that polling but also results in the AM having a strong ref to everything loaded by that request. PreloadPrimaryAssets returns the stream handle, but doesn’t do the AM stronger so you have to keep things loaded by keeping the handle or hard references alive. If someone else has a stream handle for the same files, their handle will keep the files loaded even if you release yours.

Primary Data Asset

Example on why and how to use: https://www.tomlooman.com/unreal-engine-asset-manager-async-loading/

Incorrect Primary Asset Type?

If you create the PDA instances in the project, then implement GetPrimaryAssetId, you need to resave the PDAs.

Filtering PDAs using tags

Thanks to Snaps

  • On PDA
    • Override GetAssetRegistryTags(Context)
    • Add tag to Context
  • When searching:
FAssetRegistryModule& AssetRegistryModule = FModulemanager::LoadModuleChecked<FAssetRegistryModule>("AssetRegistry");
AssetRegistryModule.Get().GetAssetsByTagValues(Tags, OutArray);

Asset Bundles

See Asset Bundles section here To include nested asset bundles see IncludeAssetBundles

Latest added/edited notes