Unreal Engine Tip: Startup Actions

In Unreal Engine there is a feature called Startup Actions.

Its purpose is to parse and import feature packs(packs you receive from Fab/Marketplace) on engine startup/initialization.

You can only specify these in the DefaultGame.ini file.

It requires bAddPacks to give permission to parse & import them.

InsertPack= is the specifier for the pack you want to import.

PackName= specifies the name of the pack from a user facing perspective for what the folder in the content folder is going to be named.

PackSource= specifies the upack file to import(don’t worry you don’t have to include the file path).

If you're wondering "Where is this file?! Where should I be placing it?!" Goodluck finding it!

(Kidding obviously) It’s located within the engine’s FeaturePacks folder.

So here’s the path using a fresh source(github) version:

• [Engine Root Path on your computer]
  • Engine/
  • FeaturePacks/
    • StarterContent.upack
    • (Other upack files)…
  • Samples/
  • Templates/
  • GenerateProjectFiles.bat
  • UE.sln
  • …

Here’s an example of how you specify which ones to import in DefaultGame.ini using the Starter Content Pack

[StartupActions]
bAddPacks=True
InsertPack=(PackSource="StarterContent.upack",PackName="StarterContent")

The code that uses this is located in:

• FFeaturePackContentSource::ImportPendingPacks(called from FUnrealEdMisc::OnInit)
• FFeaturePackContentSource::ParseAndImportPacks

You could in theory add your own version of startup actions since it’s just reading from GConfig on engine initialization and retrieve properties and configurations to run in code (I recommend in your module’s code or some sort of object specifically instanced for the initialization process only).

If you want to hook into that same initialization phase, you can bind to FEditorDelegates::OnEditorBoot