Learn Bevy Book

Introduction to this book

  • Bevy is a game engine that provides first-class low-level mechanisms for game developing.
  • Instead of feature-full, Bevy is more like "mechanism-full".
  • We may use these mechanisms to create our own features, strategies, fancy ideas, and eventually, games.
  • Building games from low-level mechanisms is overwhelming at first. We want to alleviate this initial pain.
  • This guide takes a top-down approach to give you a creator's guidance to learning Bevy.
  • Some questions I will try to answer:
    • How to start creating from scratch?
    • When creating something, what mechanisms can you use?
    • When you want to change something, what parts should you adjust?

Brief introduction to Bevy

From the offical website:

Bevy is a refreshingly simple data-driven game engine built in Rust.

  • Compared with other game engines, Bevy is representing and tracking the internal data more elegantly:
    • It helps you materialize the imaginary game world as concrete data.
    • It organizes data as Entity-Component-System (ECS), a time-tested paradigm seen in many other engines...
    • ...yet it leverages advanced Rust features to make it refreshingly simple for us to use
  • How is my experience working with Bevy?
    • Accurate: I fully control the code, the code fully controls the game world.
    • Confident: less unexpected behaviors or mysterious bugs, thanks to Rust and Bevy's clear architecture.
    • Creative: I can put things together creatively, or craft my own features, all as I want.
    • Agile: I can build, publish and iterate a game real quick.

How to use this book

  • This book begins with a tutorial that illustrates the creation process of a simple game.
  • It also serves as a quick glance of the most important features that a game engine provides.
    • You will understand when you want something in your game, which parts should you investigate deeper.
    • Then you can refer to later chapters in any order that matches the journey of your own game creation.
  • This book use lists intensively. This is for faster iteration of this book itself. It gives outlines and high-level understandings, but not extremely detailed explanations.
  • The code of this book is open-sourced at this GitHub repo. When you see tags such as ch01/step-1 in this book, it refers to the corresponding git tag in the repo. Run this command to check out the code: 
    git checkout ch01/step-1