Best place for generic code

[IrSoil]

well, i can read this question in two ways:

1. “Gameplay” systems, that is systems that isn’t tied to particular actor while not quite fitting into gamemode or gameinstance, like time-of-the-day system or some item-drop-manager.

Those are goes into Subsystems. note: this doc is lacking: UWorldSubsystem is also a thing and is missing from doc

@VantisDev

Should I make an Unreal Object that has only one instance?

If you ever question yourself “should i make a singleton for this”, in UE the answer is always “definitely use ue’s subsystems instead”

2. Generic utility functions, that mostly consist of a single function, not assembling into a particular system, and have no need to store any data, like custom LineOfSight check, IsAlive(unit), GetAllUnits() or custom math like IsPointOnScreen().

I’m having those stored as a static functions in a single class derived from UBlueprintFunctionLibrary. Well, it’s mostly a bloated junkyard of a 3k lines in sum now, but it does its work well enough.
Can also be structured into a several classes, but i find using the single generic UUtils easier than several different UKismetRenderingLibrary, UGameplayStatics, UKismetSystemLibrary, etc. Though this ones have a good reason to be separated, it doesn’t makes things easier.
Also, you does want to derive it’s from UObject(i mean UBlueprintFunctionLibrary), so you can easily expose your utilities to blueprints

Another few notes:

@VantisDev

: I want to implement some generic code that will deal with relocation logic of the character when an animation is playing and the real location of the character must be synced to. I want to do this as a logic that is completely independent from any instance and just receive characters that need relocation as a parameter.

Generally this sounds like a candidate to be implemented like an Actor’s Component

On the other side, this exact task, unless you wan’t to make something custom, in 3d game is usually handled by Animation’s root motion (if your motion for specific animation is static. If it’s dynamic, like charging to enemy, it’s another thing)