This Unity project was made in June 2024 to evaluate the capabilities and the current state of Unity's Netcode for Entities networking library, especially regarding its use for massively multiplayer online games.
It was made by Felix Beinssen for his bachelor thesis in computer science during an internship at CipSoft, an independent developer and operator of online games from Regensburg, Germany.
The project is a tech demo. It is neither a polished game nor a perfect example. It contains some representative aspects of gameplay in massively multiplayer games: Avatars in a 3D scene, moving around in 2D on a plane, being able to shoot and being hit, colliding with other avatars, colliding with an obstacle and colliding with the area's fences.
From the project a stand-alone game server running headless in a console and a stand-alone game-client with a graphical user interface can be built, both for Windows and Linux. Both use IL2CPP, not mono. The game server accepts network connections from game clients. The game client should be run on multiple PCs and each game client process can run several logical clients, using the (amazing) ThinClient feature of Netcode for Entities.
A short video about the project is available on YouTube.
The project was used to conduct load tests trying to evaluate the maximum amount of connected clients ("concurrent users"). Running on off-the-shelf hardware the game server was able to host 700+ concurrent users at 30 updates per second by the game server without visible stuttering. With higher amounts, for example with 1000+ concurrent users, the network traffic became the bottleneck, resulting in visible stuttering of the avatars. This was fully expected because synchronizing player avatars simply results in a square-growing amount of network traffic, hitting a physical limit at some point. Bottlenecks for CPU, GPU or RAM did not appear in the conducted load tests.
During our evaluation Netcode for Entities did run stable and fast and supported several hundred concurrent users. It seems to be possible to build massively multiplayer online games with it. On the other hand its documentation is below our expectations. Especially such an amazing feature like ThinClients is not really documented at all.
Unity's Entity Component System (ECS) adds both performance and complexity to a project. One must make an informed decision whether that is a good deal for the own project. On the other hand its documentation also is below our expectations. In addition ECS in its current state in June 2024 does lack basic features compared to GameObjects, for example animation, sound or user interface. This lack requires hybrid solutions, adding even more complexity and reducing performance benefits.
Among the programmers at CipSoft it is the opinion that ECS currently is not ready to be used but with the right improvements this might (and hopefully does) change in the future.
This project was made with Unity Pro version 6000.0.5f1 and Visual Studio Professional 2022 on Windows 10.
It uses Netcode for Entities (1.2.1), Burst (1.8.15), Collections (2.4.1), Entities (1.2.1), Entities Graphics (1.2.1), Input System (1.8.2), Mathematics (1.3.2), Unity Physics (1.2.1) and Unity Transport (2.1.0). It uses IL2CPP, not mono.
The project is provided "as is", without warranty of any kind or support.
The project can be built using the standard Unity 6 Build Profiles for Windows, Linux, Windows Server and Linux Server.
The game client can be started with Unity's built-in command line parameters -batchmode and -nographics which is helpful for load tests. In addition it can be started with the following custom command line parameters:
-ip <address>: Connect to game server at address.-port <number>: Connect to game server at port number.-thinClients <amount>: Start amount of thin clients within one game client process. Thin clients will send randomized input.-loadtest: Limit target frame rate to 10 frames per second (to reduce CPU load and in doing so to increase amount of game client processes on one PC).
This project uses the following libraries and assets:
- Graphy Ultimate FPS Counter by Tayx94 licensed under MIT License
- Capsule Carl by Kay Lousberg licensed under Creative Commons Zero License
- KayKit Dungeon Remastered Pack by Kay Lousberg licensed under Creative Commons Zero License
Except the libraries and assets mentioned above everything else in this repository is available under the following license:
This is free and unencumbered software released into the public domain.
Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.
In jurisdictions that recognize copyright laws, the author or authors
of this software dedicate any and all copyright interest in the
software to the public domain. We make this dedication for the benefit
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relinquishment in perpetuity of all present and future rights to this
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