What code should be avoided from an object's CD0?

[STRiFE.x (STRiFE)]

Hey,

I was wondering, what kind of code should be avoid from the CDO? I’m creating a bunch of delegates in the constructor, and I was wondering if I should avoid doing this for the CDO?

ASteamMatchmakingGameSession::ASteamMatchmakingGameSession()
{
// Should I avoid creating these in the CD0?
OnCreateSessionCompleteDelegate = FOnCreateSessionCompleteDelegate::CreateUObject(...);
// more delegates here...
}

CD0 = ClassDefaultObject. If I understand this correctly, when you spawn an object in UE4, this will be created first, and then other objects with the same type will be a copy of the CDO?

[BrUnO_XaVIeR]

If you want to work with CDO and constructors you should first learn about Object Flags, such as RF_ClassDefaultObject, and understand why they exist and how they can be used.

Some common mistakes with constructors in Unreal can brick your project to a point where it will never open in Editor again.

I had to spend long nights looking inside engine source code until I understood what Unreal is really doing with constructors…

Explaining components initialization functions flow..

When you create a BP class you usually get: Archetype Class - this is a “skeleton” of your C++ Class + Generated Code (Unreal’s Reflection System) Default Object - this is the “generated class” the engine creates every time you run it, there’s always a “Class Default Object” or “CDO”; This is where you’ll see “GEN_VARIABLE” thingies. Instanced Object - this will “spawn” in game world and copy default values from CDO once created (expose on spawn stuff, etc). So the code you’ve created there …

[STRiFE.x (STRiFE)]

Thanks for the heads up. I think I’ll just ignore this for now, and not worry about CD0 optimization.