Note: UNet is deprecated, and will be removed from Unity in the future. A new system is under development. For more information and next steps see this blog post and the FAQ. |
When you are making a multiplayer game, In addition to synchronizing the properties of networked GameObjects, you are likely to need to send, receive, and react to other pieces of information - such as when the match starts, when a player joins or leaves the match, or other information specific to your type of game, for example a notification to all players that a flag has been captured in a “capture-the-flag” style game.
Within the Unity networkingThe Unity system that enables multiplayer gaming across a computer network. More info
See in Glossary High-Level API there are three main ways to communicate this type of information.
Remote actions allow you to call a method in your script across the network. You can make the server call methods on all clients or individual clients specifically. You can also make clients call methods on the server. Using remote actions, you can pass data as parameters to your methods in a very similar way to how you call methods in local (non-multiplayer) projects.
Networking callbacks allow you to hook into built-in Unity events which occur during the course of the game, such as when players join or leave, when GameObjectsThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary are created or destroyed, or when a new SceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary is loaded. There are two types of networking callbacks that you can implement:
Network manager callbacks, for callbacks relating to the network managerA Networking component that manages the network state of a Project. More info
See in Glossary itself (such as when clients connect or disconnect)
Network behaviour callbacks, for callbacks relating to individual networked GameObjects (such as when its Start function is called, or what this particular GameObject should do if a new player joins the game)
Network messages are a “lower level” approach to sending messages (although they are still classed as part of the networking “High level API”). They allow you to send data directly between clients and the server using scripting. You can send basic types of data (int, string, etc) as well as most common Unity types (such as Vector3). Since you implement this yourself, these messages are not associated directly with any particular GameObjects or Unity events - it is up to you do decide their purpose and implement them!
Did you find this page useful? Please give it a rating:
Thanks for rating this page!
What kind of problem would you like to report?
Is something described here not working as you expect it to? It might be a Known Issue. Please check with the Issue Tracker at issuetracker.unity3d.com.
Thanks for letting us know! This page has been marked for review based on your feedback.
If you have time, you can provide more information to help us fix the problem faster.
Provide more information
You've told us this page needs code samples. If you'd like to help us further, you could provide a code sample, or tell us about what kind of code sample you'd like to see:
You've told us there are code samples on this page which don't work. If you know how to fix it, or have something better we could use instead, please let us know:
You've told us there is information missing from this page. Please tell us more about what's missing:
You've told us there is incorrect information on this page. If you know what we should change to make it correct, please tell us:
You've told us this page has unclear or confusing information. Please tell us more about what you found unclear or confusing, or let us know how we could make it clearer:
You've told us there is a spelling or grammar error on this page. Please tell us what's wrong:
You've told us this page has a problem. Please tell us more about what's wrong:
Thanks for helping to make the Unity documentation better!