Unreal Engine/C++ Interview Questions

What is a struct?

contains functions and fields that are value types.

What is an Actor?

An object placed into a level like a camera or player start location. Support 3D transformations like translation, rotation and scaling. Can be spawned and destroyed using gameplay code (C++ or blueprints) AActor is base class of all Actors

What is a subsystem?

Automatically Instanced Classes with Managed Lifetimes. Entry point for programmers where they can get Blueprint and Python exposure right away while avoiding the complexity of modifying or overriding engine classes.

What does UFunction BlueprintCallable do?

exposes the function that can be called in a blueprint or level blueprint graph

What is a class?

Contains functions, constructors, destructor, and fields that define what an object should be.

4 Tenets of Object Oriented Programming

1. Abstraction 2. Encapsulation 3. Polymorphism 4. Inheritance

SOLID Principles

1. Single responsibility 2. Open-Closed 3. Liskov Substitution 4. Interface Segregation 5. Dependency Inversion

What is a UFunction?

A C++ function recognized by unreal engine system. In C++, added right before the function declaration to expose to Blueprint Visual scripting graphs

Why Use Subsystems in Unreal Engine?

According on Unreal Engine Docs: * subsystems save time * help avoid overriding engine classes * help avoid adding more API to an already busy class * enable access to blueprints through user friendly typed nodes * enable access to Python scripts for editor scripting or for writing test code * provide modularity and consistency in codebase

What is a Pawn?

Base class of all actors that can be controlled by players or AI.

What are some examples of Function specifiers for a UFunction macro?

BlueprintCallable, BlueprintCosmetic, BlueprintAuthorityOnly, Server, Unreliable, WithValidation

Do you know what a UFUNCTION is?

C++ function recognized by Unreal Engine reflection system. Any UObject or Blueprint function library can declare a member function as a UFunction by placing the UFUNCTION macro on the line above function declaration.

What does UFunction WithValidation do?

Declares an additional function named the same as main function but with _Validate added to end. Function takes same parameters and returns a bool to indicate whether or not the call to main function should proceed

What does UFunction Unreliable do?

Function is replicated over network but can fail due to bandwidth limitations or network errors. Only valid when used in conjunction with Client or server.

What does UFunction Server do?

Function only executed on server. Declares an additional function named the same as main function but with _Implementation added to the end. Autogenerated code will call the _Implementation method when necessary

What does UFunction BlueprintAuthorityOnly do?

Function only executes from Blueprint code if running on a machine with network authority. Examples of network authority include, server, dedicated server, or single player game

Are you familiar with the GAS System?

Gameplay Ability System (Paragon?)

What is BlueprintCallbable used for?

Is a function specifier for the UFUNCTION macro which allows the function to be executed in Blueprint or Level Blueprint graphs.

What is an APlayerController?

PlayerController is the interface between the pawn and the human player controlling it. Implements functionality for taking input data from player and translating it into actions like movement, using items, firing a gun ,etc. "Represents Human Player's will" from unreal engine docs PlayerController decides what to do and then issues commands to the pawn.

What is a NavigationMesh?

Provides pathfinding capabilities to AI Agents. Nav Mesh is generated from world's collision geometry to enable the AI agent to find a path between start and end locations.

Are you familiar with Unreal Engine Test Automation?

Supports Functional Testing via blueprints: https://docs.unrealengine.com/4.27/en-US/TestingAndOptimization/Automation/FunctionalTesting/

On a scale from 1 to 10 how would you rate yourself in Unreal Engine?

This question here is to determine how proficient I am at Unreal and may influence the next set of questions they ask (sets the tone) 10 - I invented or built it 9 - I contributed to it 8 - I've taught others how to use it 7 - I've used it a long time 6 - I've used it some time 5 - know a good amount but still finding my way around 4 - I know some things about it 3 - just started using it 2 - going to use it for the right thing 1 - never heard of it

What does UFunction BlueprintCosmetic do?

function marked as cosmetic and won't be run on dedicated servers.