====== Lab 8: Networking ======

{{:public:t-vien-14-1:lab8-screen.png?300|}}

===== Goal =====

The goal of this lab is to create a very simple shared virtual environment using Unity's networking support. 

===== Preparation =====

  * Nothing

===== Documentation =====

  * Unity's [[https://docs.unity3d.com/Documentation/Components/NetworkReferenceGuide.html|Networking Reference Guide]]
  * This lab is based on the [[http://cgcookie.com/unity/2011/12/20/introduction-to-networking-in-unity/|CG Cookie Introduction to Networking]] video tutorial

===== Procedure =====

  - **Empty Scene** Make an empty scene with a ground and a directional light. Position the camera such that you have a good view of the ground plane.
  - **Create Network Manager** Create a new ''GameObject'' (**GameObject->CreateEmpty**) and name it "NetworkManager". Create a new C# script called "Networking.cs" and attach it to this new game object. Paste the following code into this script:<code csharp>using UnityEngine;
using System.Collections;

public class Networking : MonoBehaviour {

	public GameObject playerPrefab;
	public Transform spawnObject;
	bool initialized = false;

	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
	
	}

	void OnGUI() {
		if(!initialized) {
			if(GUI.Button (new Rect(10,10,100,30),"Start Server")) {
				Network.InitializeServer(32,2500,true);
			}
			if(GUI.Button (new Rect(10,100,100,30),"Start Client")) {
				Network.Connect ("127.0.0.1",2500);
			}
		}

	}

    void OnServerInitialized() {
		initialized = true;
		Debug.Log ("Server Initialized");
		spawnPlayer();
	}

	void OnConnectedToServer() {
		initialized = true;
		spawnPlayer();
	}

	void spawnPlayer() {
		Network.Instantiate(playerPrefab, spawnObject.position, Quaternion.identity,0);
	}
}
</code>
  - **Create Player** Create a regular cube (**GameObject->CreateOther->Cube**). Change its name to "NetworkPlayer". Add a ''CharacterMotor'' component to it (**Component->Character->CharacterMotor**). Add a ''NetworkView'' component to it (**Component->Miscellaneous->NetworkView**). Create a new C# script called "CharacterMovement.cs" and add the following code to it:<code csharp>using UnityEngine;
using System.Collections;

public class CharacterMovement : MonoBehaviour {

 	public float speed = 5.0f;
	public float gravity = 5.0f;

	private CharacterController cc;

	// Use this for initialization
	void Start () {
		cc = GetComponent<CharacterController>();
	}
	
	// Update is called once per frame
	void Update () {
		if(networkView.isMine) {
			cc.Move (new Vector3(Input.GetAxis ("Horizontal")*speed*Time.deltaTime, -gravity*Time.deltaTime, Input.GetAxis("Vertical")*speed*Time.deltaTime));
		}
	}
}</code>
  - **Turn Player into Prefab** Drag your ''NetworkedPlayer'' object into the project panel to create a Prefab and **delete** the original instance in the Hierarchy view.
  - **Create a Spawn Point** Create a new empty game object and call it "SpawnPoint". Place it well **above** the plane. 
  - **Finalize Networking** Choose the ''NetworkManager'' and drag the ''NetworkPlayer'' **PreFab** into the ''Player Prefab'' property and drag the ''SpawnObject'' game object into the ''Spawn Object'' property.
  - **Build Stand Alone** Go to **File->Build Settings...** and press **Player Settings...**. Under **Resolution** check the box marked **Run in Background**. Build a stand alone application and run it. Press **Start Server** in the application. Make sure you can move the box with the arrow keys. Start a second instance of the application but chose **Start Client** this time. Make sure you can move the cube, and see it move in both applications!