Book Image

Unity Multiplayer Games

By : Alan R. Stagner
Book Image

Unity Multiplayer Games

By: Alan R. Stagner

Overview of this book

Unity is a game development engine that is fully integrated with a complete set of intuitive tools and rapid workflows used to create interactive 3D content. Multiplayer games have long been a staple of video games, and online multiplayer games have seen an explosion in popularity in recent years. Unity provides a unique platform for independent developers to create the most in-demand multiplayer experiences, from relaxing social MMOs to adrenaline-pumping competitive shooters. A practical guide to writing a variety of online multiplayer games with the Unity game engine, using a multitude of networking middleware from player-hosted games to standalone dedicated servers to cloud multiplayer technology. You can create a wide variety of online games with the Unity 4 as well as Unity 3 Engine. You will learn all the skills needed to make any multiplayer game you can think of using this practical guide. We break down complex multiplayer games into basic components, for different kinds of games, whether they be large multi-user environments or small 8-player action games. You will get started by learning networking technologies for a variety of situations with a Pong game, and also host a game server and learn to connect to it.Then, we will show you how to structure your game logic to work in a multiplayer environment. We will cover how to implement client-side game logic for player-hosted games and server-side game logic for MMO-style games, as well as how to deal with network latency, unreliability, and security. You will then gain an understanding of the Photon Server while creating a star collector game; and later, the Player.IO by creating a multiplayer RTS prototype game. You will also learn using PubNub with Unity by creating a chatbox application. Unity Multiplayer Games will help you learn how to use the most popular networking middleware available for Unity, from peer-oriented setups to dedicated server technology.
Table of Contents (14 chapters)
Unity Multiplayer Games
About the Author
About the Reviewers

Moving hit detection to the server

Our first order of business is to move the raycast function to the server.

We have a readymade solution for this—we can simply mark our Fire function as an RPC, and instead of calling it directly, we broadcast an RPC instead.

First, we'll modify our Fire function as follows:

void Fire()
  // this code should never execute on any machine other than the server/host
  if( !Network.isServer )

  RaycastHit hit;
  if( Physics.Raycast( transform.position, transform.forward, out hit, 100f, HitLayers ) )
    // let a script on the object handle taking damage
    hit.collider.SendMessage( "TakeDamage", Damage, SendMessageOptions.DontRequireReceiver );

We'll then send an RPC to call the Fire function rather than directly calling it:

void Update()
  if( networkView.isMine && Input.GetMouseButtonDown( 0 ) )
    // if we're the server, just directly call the function
    // remember, server cannot use RPCMode.Server, the RPC is...