Feiner, COMS W4172, Spring 2018

Introduction to Networking in Unity

Carmine ElvezioProf. Steve Feiner

COMS 4172March 22, 2018

Basic Networking Concepts

Server/Client communication handled by Unity

Clients connect to listening server

Single server—multiple clients

Unity applications can be configured as server, client, or host

Hosts in UNET are servers with a local client instance

Clients control local “players”

Players can be configured to have local authority

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Feiner, COMS W4172, Spring 2018

Networking in Unity

New networking system introduced in 2015: UNET

Older, deprecated net framework still present—do not use!

Deprecated components are labeled

UNET

High-level scripting API (HLAPI)

Lower-level transport API

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UNET

http://docs.unity3d.com/Manual/UNetUsingHLAPI.html4

Feiner, COMS W4172, Spring 2018

NetworkManager

The starting point of a basic networked application—use it!

This can be used to easily configure both server and client through a single component

Exposes settings for player, other prefab objects, and some network transmission settings

http://docs.unity3d.com/Manual/UNetManager.htmlhttp://docs.unity3d.com/ScriptReference/Networking.NetworkManager.html 5

NetworkManager

Network Address

Client will try to connect to this IP over specified port

Server Bind To IP

Server can listen to specific IP address

Can configure matchmaking settings from this component as well

Derive from NetworkManager for more advanced control over settings & callbacks

http://docs.unity3d.com/Manual/UNetManager.htmlhttp://docs.unity3d.com/ScriptReference/Networking.NetworkManager.html 6

Feiner, COMS W4172, Spring 2018

NetworkManager

Enable Advanced Configuration to tune performance for your application

Add/Remove/Edit QoS Channels to specify behavior per channel

Unreliable—send message with no guarantees of receipt

Reliable—All messages will be sent, may slow updates

AllCostDelivery,ReliableFragmented, etc.

http://docs.unity3d.com/Manual/UNetManager.htmlhttp://docs.unity3d.com/ScriptReference/Networking.NetworkManager.htmlhttp://docs.unity3d.com/ScriptReference/Networking.QosType.htmlhttp://blogs.unity3d.com/2014/06/11/all-about-the-unity-networking-transport-layer/ 7

NetworkHUD

Very convenient GUI that can be used in all deployments to easily control network settings at runtime

Also has editor controls

Click LAN Host to create Server/Client application

Click LAN Server Only to create server

Click LAN client to create client

Need to specify target IP

http://docs.unity3d.com/Manual/class-NetworkManagerHUD.html8

Feiner, COMS W4172, Spring 2018

NetworkServer

Get Handle to a NetworkManager in the scene

GameObject.GetComponent<NetworkManager>()

Start Server with NetworkManagerName.StartHost() or NetworkManagerName.StartServer()

Get access to server through NetworkServer

NetworkManager provides handles to some NetworkServer features

Alternatively, create NetworkServer object and start with NetworkServer.Listen(PortNumber)

Register Handlers with NetworkServer.RegisterHandler(MsgType.Type, FuncName)

http://docs.unity3d.com/Manual/class-NetworkServer.htmlhttp://docs.unity3d.com/ScriptReference/Networking.NetworkServer.html 9

NetworkClient

Get Handle to a NetworkManager in the scene

GameObject.GetComponent<NetworkManager>()

Start Client with NetworkManagerName.StartHost() or NetworkManagerName.StartClient()

Get access to client through NetworkManager.Client, which returns client object, or NetworkClient.Instance

You can also configure an external client (useful for assigning specific instantiation behavior)

Alternatively, start system using NetworkClient.Connect(IPAddress, Port)

Register Handlers with ClientObj.RegisterHandler(MsgType.Type, FuncName)

http://docs.unity3d.com/Manual/class-NetworkClient.htmlhttp://docs.unity3d.com/ScriptReference/Networking.NetworkClient.Connect.html 10

Feiner, COMS W4172, Spring 2018

NetworkIdentity

NetworkIdentity is Component that must be attached to all GameObjects that will interact over the network

Attaching it will delay the Start Function & enabling of the GameObjects and attached components until network communication is established

Set Server Only to prevent spawning on clients

http://docs.unity3d.com/Manual/class-NetworkIdentity.html11

NetworkIdentity

Local Player Authority: Allow client to own network objects instantiated for the client specifically

Required to allow clients to send “Commands” to server

AssetID: ID of Prefab used to create object

SceneID: ID of object in the scene (the GUID of scene objects)

NetworkID: ID of object in current network session

12http://docs.unity3d.com/Manual/class-NetworkIdentity.html

Feiner, COMS W4172, Spring 2018

NetworkBehaviour

NetworkBehaviours allow for special UNET-compatible functions and variables that can be executed over the network

Derives from MonoBehaviour

Objects with NetworkBehaviours will not start until spawned by a NetworkServer with NetworkServer.Spawn()

May also be spawned automatically by NetworkServer, if already present in scene

http://docs.unity3d.com/Manual/class-NetworkBehaviour.htmlhttp://docs.unity3d.com/ScriptReference/Networking.NetworkBehaviour.html 13

NetworkBehaviour

Synchronized variables for basic types

Tag variables with [SyncVar]

Network-based Callback Registration

OnStartServer, OnStartClient, OnSerialize, OnDeSerialize, etc.

{Client/Server}-specific functions

Allow you to specify methods that can be executed only on the server or client, with [Server] or [Client] tags, respectively

http://docs.unity3d.com/Manual/class-NetworkBehaviour.htmlhttp://docs.unity3d.com/ScriptReference/Networking.NetworkBehaviour.html 14

Feiner, COMS W4172, Spring 2018

NetworkBehaviour

RPC Calls to Client

Allow server to invoke methods on clients

Add [ClientRpc] tag

Add “Rpc” before method name

http://docs.unity3d.com/Manual/class-NetworkBehaviour.htmlhttp://docs.unity3d.com/ScriptReference/Networking.NetworkBehaviour.html 15

NetworkBehaviour

Client-to-Server Commands

Allow client to invoke methods on Server

Need Local Player Authority on attached NetworkIdentity

Add [Command] tag

Add “Cmd” before method name

http://docs.unity3d.com/Manual/class-NetworkBehaviour.htmlhttp://docs.unity3d.com/ScriptReference/Networking.NetworkBehaviour.html 16

Feiner, COMS W4172, Spring 2018

NetworkBehaviour

Network-based Events

Event system, powered by network messages, that can trigger other behaviors throughout project

Create delegate for your event

Declare member of that delegate

Add [SyncEvent] tag to event members

http://docs.unity3d.com/Manual/class-NetworkBehaviour.htmlhttp://docs.unity3d.com/ScriptReference/Networking.NetworkBehaviour.html 17

NetworkTransform

Component allowing network synchronization of GameObject transformation components

As with standard NetworkBehaviour, optimized to send updates when object state is changed

Sync Options:

Transform, Rigidbody2D/3D

Change NetworkSendRate for more frequent updates (smoothing the transformation)

Set to 0 for objects that will not update (over network) after creation

http://docs.unity3d.com/Manual/class-NetworkTransform.html18

Feiner, COMS W4172, Spring 2018

NetworkTransform

Smooth translation on clients with InterpolateMovement

The higher the number, the faster the interpolation

Smooth rotation on clients with InterpolateRotation

The higher the number, the faster the interpolation

Set rotation axis with RotationAxis

Set CompressRotation to Low/High and SyncAngularVelocity, to further customize rotation behavior

http://docs.unity3d.com/Manual/class-NetworkTransform.html19

Thank You!Questions?

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