How to make a game engine: The Beginners Guide to build a game engine

Beginners guide to developing a game engine.

Beginners guide to developing a game engine.

Game engines can seem intimidating for aspiring game developers. But making your own simple game engine can be a fun learning experience and empower you to create the games you want. In this comprehensive guide, you’ll learn the key aspects on How to make a game engine from scratch.

A computer screen displaying a mountain scene, showcasing game engine capabilities.

Contents: How to make a game engine

Why Make Your Own Game Engine?

While commercial engines like Unity and Unreal Engine provide awesome tools for game development, making your own engine allows for limitless customization and control. With your own engine, you can tailor every aspect to fit your game’s unique needs. Building an engine also helps you deeply understand how game engines work under the hood. This knowledge will make you a better game programmer down the road.

Some other benefits of making your own game engine include:

So if you want full creative freedom and a great programming challenge, building an engine from scratch may be for you. Just be ready to invest significant development time.

How to make a game engine – A screenshot of a computer screen displaying a video game created using a game engine. Source: GodotEngine

What You’ll Need to Get Started

To build a game engine, you’ll need:

Many engine components can be built separately as libraries, like renderers, resource managers, etc. This modular approach lets you swap out parts of the engine as needed.

10 Key Aspects of a Game Engine

Now let’s break down the major components that go into a game engine:

1. Rendering Engine

The rendering engine is responsible for drawing and displaying graphics each frame. It communicates with the GPU (graphics processing unit) to turn 3D models and environments into 2D images on the screen.

The key tasks of a rendering engine include:

For beginners, start by rendering simple 2D sprites, shapes and images. This will teach fundamentals like submitting geometry to the GPU, configuring shaders, managing render state and displaying outputs.

Slowly add support for features like animated 3D models, environment maps, normal/bump mapping, shadow mapping, and different lighting techniques. Aim to have sufficient rendering capabilities for simple 3D scenes before expanding the engine’s feature set.

Some key graphics APIs to use for rendering include OpenGL, Direct3D, Vulkan, and Metal.

How to make a game engine – Adobe photoshop cs5 tutorial – how to create a 3d image using game engine.

2. Windowing and Input System

The windowing system creates and manages application windows to display graphics on screen. The input system detects and responds to user input from devices like keyboard, mouse and gamepad.


The windowing system handles tasks like:

Popular cross-platform windowing libraries:

SDLSimple windowing capabilities with OpenGL support
GLFWFocused on OpenGL context creation
SFMLSimple windowing as part of broader framework


The input system detects and processes different input events:

Input APIs like SDL, GLFW and SFML provide cross-platform input event handling.

Prioritizing keyboard/mouse input early on is recommended, along with basic gamepad support. Multi-touch can be added later as needed.

3. Resource Management

The resource management system loads game assets like textures, 3D models, audio clips, and other data for use during gameplay. Resources are identified by unique string IDs rather than directly using file paths.

Key Responsibilities

Typical Game Resources

Resource TypeFile Formats
TexturesPNG, JPG, TGA, DDS
AudioWAV, MP3, OGG
ShadersGLSL, Cg, HLSL
Game DataJSON, XML, custom formats

Resource Manager Design

The resource manager can be designed as a centralized singleton system that handles asynchronous loading requests from other engine systems and game code.

thread can be dedicated to streaming resources from disk or networked sources to minimize load hitches.

A cache stores loaded resources for fast access based on string IDs. The manager unloads resources based on configurable caching policies, like a Least Recently Used (LRU) scheme.

4. Game Loop

The game loop is the central engine component that drives all gameplay and rendering. It runs continuously to process input, update game logic, render scenes, and handle events.

Typical Game Loop Steps

On each loop iteration, the game loop performs this sequence of operations:

  1. Process system events like window messages
  2. Process input from devices
  3. Update game logic and state
  4. Update physics simulation
  5. Update camera positions
  6. Render 3D scene
  7. Render 2D overlay like UI
  8. Swap framebuffers

This loop runs at the target frame rate, often 60 times per second, to provide smooth real-time interaction.

Variable Timestep

Rather than fixed timesteps, it’s better to support variable delta times based on actual frame duration:

while (gameIsRunning) {

  float dt = timeSinceLastFrame; 



This ensures consistent gameplay independently of frame rate.

Game Loop Architecture

The game loop can be implemented as its own class or module. It encapsulates the core real-time gameplay architecture.

Other engine systems hook into the game loop by registering update functions to be called each frame. The loop itself is platform-agnostic.

How to make a game engine – A tutorial on creating a game engine.

5. Scenes and Game Objects

Scenes represent levels or areas in the game world. They contain game objects like characters, items, terrain, etc. The scene system organizes game objects for efficient rendering and simulation.

Scene Graph

A scene is structured as a graph or tree of game object nodes:

This allows complex object hierarchies to be built and manipulated efficiently.

Typical Scene Nodes

Node TypeDescription
StaticMeshA complex mesh object that does not move
SkeletalMeshAn animated character model
CameraA viewpoint from which the scene is rendered
LightA light source like a point or directional light
ParticleSystemA simulated particle effect like smoke

Game Object Implementation

Game objects encapsulate data like meshes, materials, physics bodies, and behaviors. They expose functionality through interfaces like:

This separates object capabilities from their specific implementations.

Scenes and game objects are core engine components that enable efficient scene management and rendering.

6. Physics Engine

The physics engine simulates Newtonian physics for realistic object interactions including collisions, dynamics and constraints. This brings the game world to life.

Key Physics Areas

Rigid Body Physics

The physics engine treats objects like rigid bodies that respond to forces and torque over time:

force = mass * acceleration
torque = inertia * angularAcceleration

Integrating these values simulates realistic movement and collisions.

Popular Physics Engines

Box2D2D physics for games
BulletReal-time 3D physics
PhysXRobust 3D physics from Nvidia
HavokCross-platform physics SDK

Box2D is a great choice for 2D games. Integrating a dedicated physics engine offloads thousands of lines of complex code.


Complex physics are expensive to simulate. Techniques like spatial partitioning, sleeping inactive objects, and avoiding unnecessary work are key for optimal performance.

Physics brings key aspects of real-world physical behavior to games, like collisions, gravity, mass, friction, springs, joints and fluid dynamics. This vastly expands the potential for interesting mechanics and gameplay.

7. Spatial Partitioning

Spatial partitioning refers to dividing game world space into regions and layers to organize objects for efficient operations like culling and queries.

Types of Spatial Partitions

GridsDivide world into grid cells like cubes
BSP TreesBinary space partitioning tree
OctreesRecursively subdivide space into octants
QuadtreesRecursively subdivide space into quadrants (2D)


Grid Implementation

A simple grid divides world space into equal cube cells like 10 x 10 x 10. Game objects are grouped into whatever cell their position falls inside.

Cells outside camera view can be quickly skipped. Neighboring cells are checked for proximity queries.

BSP Trees

Binary space partitioning recursively subdivides space with splitting planes. This builds a tree structure useful for segmentation, culling and queries.

BSP trees have fast query times but rebuilding the tree with dynamic data is expensive.


Octrees recursively subdivide cubes into eight octants until a size threshold is met. Octrees are common in 3D games for view frustum culling and proximity queries.

Spatial partitioning tailors data access patterns around 3D spatial locality. This brings huge performance gains.

The animation system brings game models to life by controlling their motions, blending animations, and allowing for dynamic effects during gameplay.

How to make a game engine – A screen displaying settings for a game engine.

8. Animation System

Animation Types

SkeletalBones and skins attached to models
VertexAnimating individual mesh vertices
Morph TargetBlending between predefined vertex positions

Skeletal Animation

Most common. Skinned model has internal bone skeleton animated by changing bone orientations over time. Smooth transitions between animations are achieved by blending.


Animations can be triggered based on game logic and input:

State Machines

Manage blending between animation states like idle, walking, attacking. Popular for controlling character movement.

Animation Data

Stored in formats like FBX, COLLADA, glTF. Provides bone hierarchies, pivot points, and keyframe position/rotation data.

Animation systems bring characters and models to life with natural, dynamic motion. This immensely expands the expressive potential of games.

9. Audio System

The audio system plays sound effects and background music to heighten immersion during gameplay.

Key Features

Audio APIs

OpenALCross-platform 3D audio
FMODRobust audio engine and authoring tool
XAudio2Low-level audio on Windows

Sound Resource Formats


The audio system interfaces with a backend API to handle playback. Sounds are triggered from game code and can be positioned in 3D space. Background music loops seamlessly.

Optimizations like object pooling minimize latency. Streaming large audio files avoids hogging memory.

Immersive audio expands the sensory experience dramatically. Engine audio brings environments and gameplay to life.

10. Scripting and Gameplay

Scripting provides a framework for implementing game mechanics, behaviors and logic without hard-coding everything into the engine.

Benefits of Scripting


A popular embedded scripting language. Easy to interface with C/C++.

Typical Gameplay Scripts

CharacterControllerHandles player movement and actions
AIControllerManages AI behavior and decision making
DialogManagerControls dialog sequences and branching
QuestManagerManages quest objectives and states
UIManagerUpdates UI elements and handles events


The scripting system allows code scripts to be attached to game objects. Scripts expose functions the engine can call like Start(), Update(), OnCollision(), etc.

Script state is maintained securely between engine updates. Some overhead occurs when crossing the native/scripting language barrier.

Combined with other engines systems, scripting provides the framework for implementing all gameplay elements like game modes, rules, sequences, UI, and more that make your game unique.

Where to Start When Making an Engine?

Building a full-featured game engine is a massive undertaking. Scope creep can quickly sabotage your progress. That’s why it’s smart to start small and simple.

Aim to make a basic 2D engine first. Get a window opening, sprites rendering, and basic input working. Expand the engine piece by piece after that, like adding a physics engine or 3D renderer.

Some helpful starting points:

Choosing a clear subset of features to tackle first will get your engine off the ground smoothly. Resist adding everything at once. Focus on core functionality before polish.

Leveraging Existing Libraries

Don’t reinvent the wheel unnecessarily. Many excellent open source libraries exist for common tasks like audio, input, image loading, networking, GUI, etc. Integrate established libraries into your engine to avoid writing boilerplate code.

Some popular C++ libraries used by game engines include:

Do some research to find libraries that suit your engine requirements. They will provide helpful building blocks.

Optimizing Game Engine Performance

Performance is critical for good gameplay. A sluggish framerate ruins immersion. Here are some tips for optimizing engine speed:

The key is only doing work that contributes directly to better visuals or gameplay. Constantly measure frame times and aim for 60+ FPS.

Remember Key Points When Making an Engine

To recap, here are some key takeaways:

While creating a game engine from scratch is challenging, doing so can teach you an immense amount about real-time graphics, physics, gameplay programming, and more. Apply an iterative approach to build your skills progressively. Before long, you’ll have your own custom engine powering the games you’ve always wanted to create!

Conclusion: How to make a game engine

Building your own game engine from the ground up is a challenging but rewarding endeavor.

While existing engines like Unity provide plenty of power out of the box, creating your own engine enables complete customization and control for your specific game. Start with a minimal prototype, leverage helpful libraries, focus on core functionality first, and expand the engine incrementally.

Optimization and rapid iteration are key. With perseverance and incremental progress, you’ll gain deep knowledge of real-time graphics, physics, gameplay programming, and more. Before you know it, your custom engine will be powering the games you’ve dreamed of making. The journey to create your own game engine teaches you invaluable skills along the way.

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FAQ How to make a game engine?

Q: What is game engine development?

A: Game engine development refers to the process of creating a software framework that is used to build, develop, and run video games. It involves writing code, designing systems, and implementing various features that are necessary for creating a functioning game.

Q: Why would I want to make my own game engine?

A: Making your own game engine can be a rewarding experience for several reasons. It allows you to have full control over the development process, customize the engine to fit your specific needs, and gain a deeper understanding of the inner workings of game development.

Q: Do I need to be an expert programmer to create a game engine?

A: While having programming knowledge certainly helps, you don’t need to be an expert to create a game engine. However, a basic understanding of programming concepts, such as variables, loops, and functions, is necessary to start the process.

Q: What are some important aspects of game engine development?

A: Game engine development involves various aspects, including rendering graphics, handling user input, managing game assets, implementing physics simulations, and creating an efficient game loop. These are some of the key components that need to be considered when building a game engine.

Q: Can I use an existing game engine instead of creating my own?

A: Absolutely! Using an existing game engine, such as Unity or Unreal Engine, can save you a lot of time and effort. These game engines come with built-in tools and features that make game development easier for developers of all skill levels.

Q: What are some popular game engines that I can use?

A: Some popular game engines that you can use for developing your games include Unity, Unreal Engine, Godot, and SDL. Each of these engines has its own set of features and benefits, so it’s important to choose one that aligns with your specific needs and goals.

Q: How long does it take to create a game engine?

A: The time it takes to create a game engine can vary depending on the complexity of the engine and the skill level of the developer. It can take anywhere from several months to several years to develop a fully functional game engine.

Q: What programming languages are commonly used for game engine development?

A: Some commonly used programming languages for game engine development include C++, C#, Java, and Python. These languages offer robust capabilities and are widely supported in the game development community.

Q: Can I create a game engine for a specific type of game, such as a 2D game?

A: Yes, you can create a game engine specifically tailored for a certain type of game, such as a 2D game. By focusing on the requirements and unique aspects of the game genre, you can develop a game engine that optimizes performance and provides the necessary tools for creating immersive gameplay.

Q: Are there any resources available to help me learn how to make a game engine?

A: Yes, there are resources available that can help you learn how to make a game engine. Online tutorials, books, forums, and online communities dedicated to game development are great options for gaining knowledge and guidance throughout the process.

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