gwiedemair/overload

3D Game engine with editor

Context

Overload is a graduation project. We were 3 (Benjamin VIRANIN, Max BRUN and me) working on during 5 months. We had to create a game engine from scratch, using the fewest libraries possible.

Team goals

Our goals for this project were:

• Understanding how to architect a game engine
• Designing an application thinking of end-users
• Making a game engine as simple as possible
• Producing high-quality modern code
• Creating a game with our engine
• Dealing with a long-term project
• Developping documentation for developers and end-users

Software used

• Visual Studio 2017 and 2019 to code

Libraries used

• OpenGL with GLEW (Graphics API)
• GLFW (Windowing and inputs)
• Assimp (3D model loader)
• Bullet3 (Physics)
• irrKlang (Audio)
• Tinyxml2 (XML Serializer)
• SOL2 (Lua binder)
• imGui (GUI)

Pre-production

We spent about a month designing our initial architecture. We tried to provide a technical solution with UML diagrams, flowcharts, package diagrams and use-case diagrams. This was a long and tedious work, but it really helped us to start the production with a clear vision of the engine. We defined some coding convention to ensure that all of our work will stay homogeneous during the production. Defining these kinds of rules is crucial to keep a maintainable code during the whole project.

Production

The production made us realize that we had a naive idea of what a game engine is. During this phase our architecture has evolved. We found that our initial architecture was sometimes too complex, non-optimal. We went back to architecture design multiple times during the project.

Modules

Our final solution is divided into 12 modules:

• OvAnalytics: Code and hardware profiling
• OvDebug: Logging, assertions
• OvTools: Serialization, ini files, events, time
• OvMaths: Vectors, Matrices, Quaternion, Transform
• OvAudio: Wraps irrKlang
• OvPhysics: Wraps Bullet3
• OvRendering: Rendering engine using OpenGL
• OvWindowing: GLFW + Windows API wrapper
• OvUI: imGui wrapped into an event-based and component-based UI system
• OvCore: Mediator, resource management, scripting, component-based scene system
• OvGame: Uses OvCore, asset dependent, generic executable for any game built with Overload
• OvEditor: Uses OvCore, expose game development to the end-user (From creation to build)

Team organization

At the beginning of the project we decided to split the main tasks like this:

• Rendering: Max BRUN
• Physics and audio: Benjamin VIRANIN
• Core and editor: Me

But the more the project progressed, the more we moved. We all worked on every parts of the engine, and it was a good way to expand our areas of expertise. Finally, although I focused more on the core and the editor, I helped my teammates on their modules.

Features

We end-up this project with much more features than we expected. We used an iterative strategy, meaning that we developped our modules as simple as possible in order to quickly have results. We then iterated over and over to add new features.

Game

We made a game with our engine to demonstrate its capabilities. Our game has a complete game loop (Menu, story, cinematic, game, credits).

Build information

We made this project using Visual Studio 2017. If you want to build Overload you should consider using this IDE.
Overload only supports Windows x64.

Licence

This software may not be resold, redistributed or otherwise conveyed to a third party.

More information

If you are interested in Overload, you can download our engine and the demo game we made with it on our website:
http://overloadengine.org

You can also watch our features reel on YouTube:
https://www.youtube.com/watch?v=ARXSJh-ZMHM

And join our Discord Server:
https://discord.gg/wqe775s

Credits

• Adrien GIVRY
• Max BRUN
• Benjamin VIRANIN

Images