It’s the little things that matter.

If you’re building your own custom actors and components in Unreal Engine 4, then at some point you’ll want to give them a nice icon instead of the default generic one. It’s actually pretty easy to do, but it took me quite a bit of digging since I couldn’t find a ready-made guide. It boils down to the following:

• Create a SlateStyleSet
• Set its ContentRoot and CoreContentRoot properly
• Register SlateImageBrushes for your actor or component
• Register your SlateStyleSet
• Register your SlateStyleSet as an icon source

On startup, create and register:

TSharedRef<FSlateStyleSet> StyleSet = MakeShareable(new FSlateStyleSet("MyStyleSet"));
	
StyleSet->SetContentRoot(FPaths::EngineContentDir() / TEXT("Editor/Slate"));
StyleSet->SetCoreContentRoot(FPaths::EngineContentDir() / TEXT("Slate"));

StyleSet->Set("ClassIcon.MyActor", new FSlateImageBrush("path/to/MyActor16.png", FVector2D(16.0f, 16.0f)));
StyleSet->Set("ClassThumbnail.MyActor", new FSlateImageBrush("path/to/MyActor64.png", FVector2D(64.0f, 64.0f)));

StyleSet->Set("ClassIcon.MyComponent", new FSlateImageBrush("path/to/MyComponent16.png", FVector2D(16.0f, 16.0f)));

FSlateStyleRegistry::RegisterSlateStyle(*StyleSet.Get());
FClassIconFinder::RegisterIconSource(StyleSet.Get());

On shutdown, clean up:

FClassIconFinder::UnregisterIconSource(StyleSet.Get());
FSlateStyleRegistry::UnRegisterSlateStyle(*StyleSet.Get());
ensure(StyleSet.IsUnique());
StyleSet.Reset();