Introduction

Unraveling complex codebases: navigating Unreal Engine from a programmer's perspective

Welcome to the Unreal Engine Code Analysis Substack.

My name is Hussein - I’ve been working in the gaming industry for over a decade as a programmer for studios such as Eidos, Ubisoft and Gearbox.

Codebases, regardless of their size, often have complex logic and interdependencies that may not be immediately evident. This is compounded by code frequently switching hands, with the original developer often not involved in subsequent changes. As the initial vision evolves and new ideas are integrated, the complexity of the architecture can grow, sometimes stretching beyond its original design intentions.

This led me over the years to develop my own approach for delving into unfamiliar (and sometimes unwelcoming) code and trying to make sense of it all.

It starts with documenting systems in manageable pieces that we can always go back to in order to get a quick refresher. The goal is not to understand everything from the get-go, but rather to establish a foothold within the codebase which slowly expands, one step at a time, to eventually cover as much as possible.

This leads to understanding the overall logic, runtime data flow, and technical limitations. This in turn helps us recognize the impact of our changes, how to interface with the systems, as well as schedule work with a higher degree of confidence in estimates.

The official Unreal Engine documentation, while certainly useful, is not geared towards programmers and doesn’t provide that level of detail which I find important. The exercise of opening the codebase and analyzing it remains a requirement to understanding what makes the engine tick under the hood.

As such, I will be going through that exercise and documenting my own journey - hoping that some of my findings prove useful to you.

Join me as we uncover everything Unreal Engine has to offer.