# Unity3D-Python-Communication **Repository Path**: ysofar/Unity3D-Python-Communication ## Basic Information - **Project Name**: Unity3D-Python-Communication - **Description**: Unity3D-Python-Communication，这是一个非常快速、简单且通用的进程间通信示例，连接Unity3D C#和Python，使用ZeroMQ。 - **Primary Language**: C# - **License**: MIT - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 0 - **Created**: 2026-05-30 - **Last Updated**: 2026-05-30 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README # Unity3D-Python-Communication ⚡️ A very fast, simple, and general inter-process communication example between Unity3D C# and Python, using ZeroMQ. ![unity-cmd-play-example.gif](img/unity-cmd-play-example.gif) PS. It looks slow in the GIF above because I put a delay of one second between each message so that you can see it working. ## Core Pillars - **very fast** — ZeroMQ is a networking library that allows you to send huge amount of data from server to client in a short period of time. I'm talking about casually sending/receiving 10,000 requests per second. - **simple** — You don't have to explicitly open and bind a socket or know anything about low-level networking. - **general** — You can use this to send/receive any kind of data request. You can send image, video, text, JSON, file, or whatever you want. In this example, we are sending text. - **inter-process** — The communication is done inside the same machine. Which means very low-latency. ## Introduction * Have you ever tried to communicate C# code in Unity3D with Python before but could not find a satisfying solution? * Have you ever tried implementing communication protocol using file read/write and found out that it's a stupid approach? * Have you ever tried communicating using Web HTTP request and found out that it's stupidly slow and high latency? * Have you ever tried communicating using socket/TCP/UDP stuff, but it feels like you are reinventing the wheel and you are becoming a network engineer? * Have you ever tried to communicate by emulating a serial port, and found out that it's not how cool guys do work? * Have you ever tried to send Unity input to python and do some scientific work (maybe even machine learning task) and return the output to Unity? * Have you ever tried to build a `.dll` from python or even rewrite everything in `C#` because you don't know how to communicate between python and C# processes? * Have you ever tried to embed `IronPython` or `Python.NET` inside Unity but it doesn't allow you to install your amazing external python libraries? (And its minimal power is pretty ridiculous compared to your external python) * Have you ever tried to export a `TensorFlow Protobuf Graph` (Deep learning model) and use `TensorFlowSharp` or `OpenCVForUnity` to import the graph inside Unity because you want to use the model to predict stuff in Unity, but it doesn't allow you to use/utilize your new NVIDIA GeForce RTX 2080Ti, and it's also hard to code? * Tried `MLAgents`, anyone? If you answer **Yes** to any of these questions but it seems you have found no solutions, then this repository is definitely for you! (If you answered **Yes to all** questions, you and me are brothers! 😏) I've tried a lot. With a lot of searching on the internet, I've found no solutions that is simple, fast, and general enough that I can apply to any kind of communication between Python and Unity3D. All I've done in the past were simply a hack to either get my scientific computation work in Unity instead of python, or communicate between the processes painfully. _Until I found ZeroMQ approach from this [repository](https://github.com/valkjsaaa/Unity-ZeroMQ-Example) (and some head scratching)._ ## Solution Explanation I've built a `request-reply` pattern of ZeroMQ where Python (server) replies whenever Unity (client) requests a service from Python. The idea is to create a separate thread inside Unity that will send a request to python, receive a reply and log the reply to the console. ## Getting Started 1. Clone this repository using `git clone https://github.com/offchan42/Unity3D-Python-Communication.git` command. 2. Open UnityProject (its `dll` files are targeting .NET 4.x version) and run `Assets/NetMQExample/Scenes/SampleScene`. 3. Run python file `PythonFiles/server.py` using command `python server.py` on a command prompt. 4. You should start seeing messages being logged inside Unity and the command prompt. Specifically, Unity will send request with a message `Hello` 10 times, and Python will simply reply `World` 10 times. There is a one second sleep between each reply on the server (to simulate long processing time of the request). Please read the comments inside `PythonFiles/server.py` and `UnityProject/Assets/NetMQExample/Scripts/` and you will understand everything more deeply. **The most important thing is that you should follow the 4 getting started steps first. Don't skip it!** ❣️ After you've understood most of the stuff but it's not advanced enough, you should consult the official [ØMQ - The Guide](http://zguide.zeromq.org/page:all). ## Requirements * [PyZMQ](https://pyzmq.readthedocs.io/en/latest/) is the Python bindings for [ZeroMQ]((http://zeromq.org/)). You can install it using `pip install pyzmq` command or see more installation options [here](http://zeromq.org/bindings:python) or [here](https://github.com/zeromq/pyzmq). * [NetMQ](https://netmq.readthedocs.io/en/latest/) is a native C# port of ZeroMQ. Normally you need to install this using `NuGet` package manager inside `Visual Studio` when you want to build a .NET application, or you could install using `.NET CLI`. But for this repository here, you don't need to do any of the installation because we've already included `AsyncIO.dll` and `NetMQ.dll` for you inside `UnityProject/Assets/NetMQExample/Plugins/` directory. If you want to build your own `dll` files, please take a look at [this issue](https://github.com/valkjsaaa/Unity-ZeroMQ-Example/issues/7). ## Known Issues Based on [this issue](https://github.com/zeromq/netmq/issues/631), the NetMQ implementation is not working nicely with Unity. If you create more than one ZeroMQ client in Unity, the Unity editor will freeze. ## Troubleshooting * While both server and client are running and communicating fine, I kill the server process, restart the server, then both server and client seem to not be communicating anymore. Why don't they continue communicating? Is this a bug? No, this is the expected behavior of ZeroMQ because of the simplicity of the code. It's mentioned in the guide [here](http://zguide.zeromq.org/page:all#Ask-and-Ye-Shall-Receive). If you want to make the code better, which is not the focus of this example, you can learn more about ZeroMQ as suggested in the screenshot below. ![troubleshooting-1.PNG](img/troubleshooting-1.PNG) The problem is that when you restart the server, the server won't reconnect to the old client anymore. You have to restart the client also. ## Disclaimer This repository is designed to be a **minimal learning resource** for getting started. It's not a fully working high-level package. After you understand the example, my job is done. Most of the code are just copies from the official ZeroMQ tutorial. I try to make this as simple to grasp as possible, so I only log the message to the console and nothing fancy. This is to minimize the unnecessary learning curve. ## TODO * [ ] Add a complicated example of how to use it for real * [ ] Show how to do this with SocketIO. SocketIO is another approach I found very viable and stable. I use `BestHTTP` package in Unity for SocketIO client and use `python-socketio` as SocketIO server. And it does not have the issue of making Unity editor freezes.