Lav et multiplayer bilspil med PUN 2

At lave et multiplayer-spil i Unity er en kompleks opgave, men heldigvis forenkler flere løsninger udviklingsprocessen.

En sådan løsning er Photon Network. Helt konkret tager den seneste udgivelse af deres API kaldet PUN 2 sig af serverhosting og giver dig fri til at lave et multiplayer-spil, som du vil.

I denne tutorial vil jeg vise, hvordan man laver et simpelt bilspil med fysiksynkronisering ved hjælp af PUN 2.

Unity version brugt i denne øvelse: Unity 2018.3.0f2 (64-bit)

Del 1: Opsætning af PUN 2

Det første trin er at downloade en PUN 2-pakke fra Asset Store. Den indeholder alle de scripts og filer, der kræves til multiplayer-integration.

Åbn dit Unity-projekt og gå derefter til Asset Store: (vindue -> Generelt -> AssetStore) eller tryk på Ctrl+9
Søg efter "PUN 2- Free" og klik derefter på det første resultat eller klik her
Importer PUN 2-pakken, efter at overførslen er færdig

Efter pakken er importeret skal du oprette et Photon App ID, dette gøres på deres hjemmeside: https://www.photonengine.com/
Opret en ny konto (eller log ind på din eksisterende konto)
Gå til applikationssiden ved at klikke på profilikonet og derefter "Your Applications" eller følg dette link: https://dashboard.photonengine.com/en-US/PublicCloud
Klik på siden Applikationer "Create new app"

På oprettelsessiden, for Photon Type, vælg "Photon Realtime" og for navnet, skriv et vilkårligt navn og klik derefter "Create"

Som du kan se, er applikationen som standard den gratis plan. Du kan læse mere om prisplaner her

Når applikationen er oprettet, skal du kopiere app-id'et, der er placeret under app-navnet

Gå tilbage til dit Unity-projekt og gå derefter til Window -> Photon Unity Networking -> PUN Wizard
Klik på "Setup Project" i PUN Wizard, indsæt dit app-id og klik derefter "Setup Project"

PUN 2 er nu klar!

Del 2: Oprettelse af et bilspil med flere spillere

1. Oprettelse af en lobby

Lad os starte med at oprette en lobbyscene, der vil indeholde lobbylogik (gennemgang af eksisterende rum, oprettelse af nye rum osv.):

Opret en ny scene og kald den "GameLobby"
I "GameLobby"-scenen skal du oprette et nyt GameObject og kalde det "_GameLobby"
Opret et nyt C#-script og kald det "PUN2_GameLobby" og vedhæft det derefter til "_GameLobby"-objektet
Indsæt koden nedenfor i "PUN2_GameLobby" scriptet

PUN2_GameLobby.cs

using System.Collections.Generic;
using UnityEngine;
using Photon.Pun;
using Photon.Realtime;

public class PUN2_GameLobby : MonoBehaviourPunCallbacks
{

    //Our player name
    string playerName = "Player 1";
    //Users are separated from each other by gameversion (which allows you to make breaking changes).
    string gameVersion = "1.0";
    //The list of created rooms
    List<RoomInfo> createdRooms = new List<RoomInfo>();
    //Use this name when creating a Room
    string roomName = "Room 1";
    Vector2 roomListScroll = Vector2.zero;
    bool joiningRoom = false;

    // Use this for initialization
    void Start()
    {
        //Initialize Player name
        playerName = "Player " + Random.Range(111, 999);

        //This makes sure we can use PhotonNetwork.LoadLevel() on the master client and all clients in the same room sync their level automatically
        PhotonNetwork.AutomaticallySyncScene = true;

        if (!PhotonNetwork.IsConnected)
        {
            //Set the App version before connecting
            PhotonNetwork.PhotonServerSettings.AppSettings.AppVersion = gameVersion;
            PhotonNetwork.PhotonServerSettings.AppSettings.FixedRegion = "eu";
            // Connect to the photon master-server. We use the settings saved in PhotonServerSettings (a .asset file in this project)
            PhotonNetwork.ConnectUsingSettings();
        }
    }

    public override void OnDisconnected(DisconnectCause cause)
    {
        Debug.Log("OnFailedToConnectToPhoton. StatusCode: " + cause.ToString() + " ServerAddress: " + PhotonNetwork.ServerAddress);
    }

    public override void OnConnectedToMaster()
    {
        Debug.Log("OnConnectedToMaster");
        //After we connected to Master server, join the Lobby
        PhotonNetwork.JoinLobby(TypedLobby.Default);
    }

    public override void OnRoomListUpdate(List<RoomInfo> roomList)
    {
        Debug.Log("We have received the Room list");
        //After this callback, update the room list
        createdRooms = roomList;
    }

    void OnGUI()
    {
        GUI.Window(0, new Rect(Screen.width / 2 - 450, Screen.height / 2 - 200, 900, 400), LobbyWindow, "Lobby");
    }

    void LobbyWindow(int index)
    {
        //Connection Status and Room creation Button
        GUILayout.BeginHorizontal();

        GUILayout.Label("Status: " + PhotonNetwork.NetworkClientState);

        if (joiningRoom || !PhotonNetwork.IsConnected || PhotonNetwork.NetworkClientState != ClientState.JoinedLobby)
        {
            GUI.enabled = false;
        }

        GUILayout.FlexibleSpace();

        //Room name text field
        roomName = GUILayout.TextField(roomName, GUILayout.Width(250));

        if (GUILayout.Button("Create Room", GUILayout.Width(125)))
        {
            if (roomName != "")
            {
                joiningRoom = true;

                RoomOptions roomOptions = new RoomOptions();
                roomOptions.IsOpen = true;
                roomOptions.IsVisible = true;
                roomOptions.MaxPlayers = (byte)10; //Set any number

                PhotonNetwork.JoinOrCreateRoom(roomName, roomOptions, TypedLobby.Default);
            }
        }

        GUILayout.EndHorizontal();

        //Scroll through available rooms
        roomListScroll = GUILayout.BeginScrollView(roomListScroll, true, true);

        if (createdRooms.Count == 0)
        {
            GUILayout.Label("No Rooms were created yet...");
        }
        else
        {
            for (int i = 0; i < createdRooms.Count; i++)
            {
                GUILayout.BeginHorizontal("box");
                GUILayout.Label(createdRooms[i].Name, GUILayout.Width(400));
                GUILayout.Label(createdRooms[i].PlayerCount + "/" + createdRooms[i].MaxPlayers);

                GUILayout.FlexibleSpace();

                if (GUILayout.Button("Join Room"))
                {
                    joiningRoom = true;

                    //Set our Player name
                    PhotonNetwork.NickName = playerName;

                    //Join the Room
                    PhotonNetwork.JoinRoom(createdRooms[i].Name);
                }
                GUILayout.EndHorizontal();
            }
        }

        GUILayout.EndScrollView();

        //Set player name and Refresh Room button
        GUILayout.BeginHorizontal();

        GUILayout.Label("Player Name: ", GUILayout.Width(85));
        //Player name text field
        playerName = GUILayout.TextField(playerName, GUILayout.Width(250));

        GUILayout.FlexibleSpace();

        GUI.enabled = (PhotonNetwork.NetworkClientState == ClientState.JoinedLobby || PhotonNetwork.NetworkClientState == ClientState.Disconnected) && !joiningRoom;
        if (GUILayout.Button("Refresh", GUILayout.Width(100)))
        {
            if (PhotonNetwork.IsConnected)
            {
                //Re-join Lobby to get the latest Room list
                PhotonNetwork.JoinLobby(TypedLobby.Default);
            }
            else
            {
                //We are not connected, estabilish a new connection
                PhotonNetwork.ConnectUsingSettings();
            }
        }

        GUILayout.EndHorizontal();

        if (joiningRoom)
        {
            GUI.enabled = true;
            GUI.Label(new Rect(900 / 2 - 50, 400 / 2 - 10, 100, 20), "Connecting...");
        }
    }

    public override void OnCreateRoomFailed(short returnCode, string message)
    {
        Debug.Log("OnCreateRoomFailed got called. This can happen if the room exists (even if not visible). Try another room name.");
        joiningRoom = false;
    }

    public override void OnJoinRoomFailed(short returnCode, string message)
    {
        Debug.Log("OnJoinRoomFailed got called. This can happen if the room is not existing or full or closed.");
        joiningRoom = false;
    }

    public override void OnJoinRandomFailed(short returnCode, string message)
    {
        Debug.Log("OnJoinRandomFailed got called. This can happen if the room is not existing or full or closed.");
        joiningRoom = false;
    }

    public override void OnCreatedRoom()
    {
        Debug.Log("OnCreatedRoom");
        //Set our player name
        PhotonNetwork.NickName = playerName;
        //Load the Scene called Playground (Make sure it's added to build settings)
        PhotonNetwork.LoadLevel("Playground");
    }

    public override void OnJoinedRoom()
    {
        Debug.Log("OnJoinedRoom");
    }
}

2. Oprettelse af en præfabrikeret bil

Bilpræfabrikatet vil bruge en simpel fysikcontroller.

Opret et nyt GameObject og kald det "CarRoot"
Opret en ny terning og flyt den ind i "CarRoot"-objektet og skaler den derefter op langs Z- og X-aksen

Opret et nyt GameObject og navngiv det "wfl" (forkortelse for Wheel Front Left)
Tilføj Wheel Collider-komponenten til "wfl"-objektet og indstil værdierne fra billedet nedenfor:

Opret et nyt GameObject, omdøb det til "WheelTransform" og flyt det derefter ind i "wfl"-objektet
Opret en ny cylinder, flyt den ind i "WheelTransform"-objektet og drej og skaler den ned, indtil den matcher Wheel Collider-dimensionerne. I mit tilfælde er skalaen (1, 0,17, 1)

Dupliker til sidst "wfl"-objektet 3 gange for resten af hjulene og omdøb hvert objekt til henholdsvis "wfr" (Hjul foran højre), "wrr" (Hjul bagtil højre) og "wrl" (Hjul bagtil venstre)

Opret et nyt script, kald det "SC_CarController" og indsæt derefter koden nedenfor i det:

SC_CarController.cs

using UnityEngine;
using System.Collections;

public class SC_CarController : MonoBehaviour
{
    public WheelCollider WheelFL;
    public WheelCollider WheelFR;
    public WheelCollider WheelRL;
    public WheelCollider WheelRR;
    public Transform WheelFLTrans;
    public Transform WheelFRTrans;
    public Transform WheelRLTrans;
    public Transform WheelRRTrans;
    public float steeringAngle = 45;
    public float maxTorque = 1000;
    public  float maxBrakeTorque = 500;
    public Transform centerOfMass;

    float gravity = 9.8f;
    bool braked = false;
    Rigidbody rb;
    
    void Start()
    {
        rb = GetComponent<Rigidbody>();
        rb.centerOfMass = centerOfMass.transform.localPosition;
    }

    void FixedUpdate()
    {
        if (!braked)
        {
            WheelFL.brakeTorque = 0;
            WheelFR.brakeTorque = 0;
            WheelRL.brakeTorque = 0;
            WheelRR.brakeTorque = 0;
        }
        //Speed of car, Car will move as you will provide the input to it.

        WheelRR.motorTorque = maxTorque * Input.GetAxis("Vertical");
        WheelRL.motorTorque = maxTorque * Input.GetAxis("Vertical");

        //Changing car direction
        //Here we are changing the steer angle of the front tyres of the car so that we can change the car direction.
        WheelFL.steerAngle = steeringAngle * Input.GetAxis("Horizontal");
        WheelFR.steerAngle = steeringAngle * Input.GetAxis("Horizontal");
    }
    void Update()
    {
        HandBrake();

        //For tyre rotate
        WheelFLTrans.Rotate(WheelFL.rpm / 60 * 360 * Time.deltaTime, 0, 0);
        WheelFRTrans.Rotate(WheelFR.rpm / 60 * 360 * Time.deltaTime, 0, 0);
        WheelRLTrans.Rotate(WheelRL.rpm / 60 * 360 * Time.deltaTime, 0, 0);
        WheelRRTrans.Rotate(WheelRL.rpm / 60 * 360 * Time.deltaTime, 0, 0);
        //Changing tyre direction
        Vector3 temp = WheelFLTrans.localEulerAngles;
        Vector3 temp1 = WheelFRTrans.localEulerAngles;
        temp.y = WheelFL.steerAngle - (WheelFLTrans.localEulerAngles.z);
        WheelFLTrans.localEulerAngles = temp;
        temp1.y = WheelFR.steerAngle - WheelFRTrans.localEulerAngles.z;
        WheelFRTrans.localEulerAngles = temp1;
    }
    void HandBrake()
    {
        //Debug.Log("brakes " + braked);
        if (Input.GetButton("Jump"))
        {
            braked = true;
        }
        else
        {
            braked = false;
        }
        if (braked)
        {

            WheelRL.brakeTorque = maxBrakeTorque * 20;//0000;
            WheelRR.brakeTorque = maxBrakeTorque * 20;//0000;
            WheelRL.motorTorque = 0;
            WheelRR.motorTorque = 0;
        }
    }
}

Vedhæft SC_CarController script til "CarRoot" objektet
Fastgør Rigidbody-komponenten til "CarRoot"-objektet og skift dens masse til 1000
Tildel hjulvariablerne i SC_CarController (Wheel Collider for de første 4 variabler og WheelTransform for resten af de 4)

For Center of Mass-variablen skal du oprette et nyt GameObject, kalde det "CenterOfMass" og flytte det ind i "CarRoot"-objektet
Placer "CenterOfMass"-objektet i midten og lidt nedad, sådan her:

Til sidst skal du til testformål flytte hovedkameraet ind i "CarRoot"-objektet og rette det mod bilen:

Opret et nyt script, kald det "PUN2_CarSync" og indsæt derefter koden nedenfor i det:

PUN2_CarSync.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Photon.Pun;

public class PUN2_CarSync : MonoBehaviourPun, IPunObservable
{
    public MonoBehaviour[] localScripts; //Scripts that should only be enabled for the local player (Ex. Car controller)
    public GameObject[] localObjects; //Objects that should only be active for the local player (Ex. Camera)
    public Transform[] wheels; //Car wheel transforms

    Rigidbody r;
    // Values that will be synced over network
    Vector3 latestPos;
    Quaternion latestRot;
    Vector3 latestVelocity;
    Vector3 latestAngularVelocity;
    Quaternion[] wheelRotations = new Quaternion[0];
    // Lag compensation
    float currentTime = 0;
    double currentPacketTime = 0;
    double lastPacketTime = 0;
    Vector3 positionAtLastPacket = Vector3.zero;
    Quaternion rotationAtLastPacket = Quaternion.identity;
    Vector3 velocityAtLastPacket = Vector3.zero;
    Vector3 angularVelocityAtLastPacket = Vector3.zero;

    // Use this for initialization
    void Awake()
    {
        r = GetComponent<Rigidbody>();
        r.isKinematic = !photonView.IsMine;
        for (int i = 0; i < localScripts.Length; i++)
        {
            localScripts[i].enabled = photonView.IsMine;
        }
        for (int i = 0; i < localObjects.Length; i++)
        {
            localObjects[i].SetActive(photonView.IsMine);
        }
    }

    public void OnPhotonSerializeView(PhotonStream stream, PhotonMessageInfo info)
    {
        if (stream.IsWriting)
        {
            // We own this player: send the others our data
            stream.SendNext(transform.position);
            stream.SendNext(transform.rotation);
            stream.SendNext(r.velocity);
            stream.SendNext(r.angularVelocity);

            wheelRotations = new Quaternion[wheels.Length];
            for(int i = 0; i < wheels.Length; i++)
            {
                wheelRotations[i] = wheels[i].localRotation;
            }
            stream.SendNext(wheelRotations);
        }
        else
        {
            // Network player, receive data
            latestPos = (Vector3)stream.ReceiveNext();
            latestRot = (Quaternion)stream.ReceiveNext();
            latestVelocity = (Vector3)stream.ReceiveNext();
            latestAngularVelocity = (Vector3)stream.ReceiveNext();
            wheelRotations = (Quaternion[])stream.ReceiveNext();

            // Lag compensation
            currentTime = 0.0f;
            lastPacketTime = currentPacketTime;
            currentPacketTime = info.SentServerTime;
            positionAtLastPacket = transform.position;
            rotationAtLastPacket = transform.rotation;
            velocityAtLastPacket = r.velocity;
            angularVelocityAtLastPacket = r.angularVelocity;
        }
    }

    // Update is called once per frame
    void Update()
    {
        if (!photonView.IsMine)
        {
            // Lag compensation
            double timeToReachGoal = currentPacketTime - lastPacketTime;
            currentTime += Time.deltaTime;

            // Update car position and velocity
            transform.position = Vector3.Lerp(positionAtLastPacket, latestPos, (float)(currentTime / timeToReachGoal));
            transform.rotation = Quaternion.Lerp(rotationAtLastPacket, latestRot, (float)(currentTime / timeToReachGoal));
            r.velocity = Vector3.Lerp(velocityAtLastPacket, latestVelocity, (float)(currentTime / timeToReachGoal));
            r.angularVelocity = Vector3.Lerp(angularVelocityAtLastPacket, latestAngularVelocity, (float)(currentTime / timeToReachGoal));

            //Apply wheel rotation
            if(wheelRotations.Length == wheels.Length)
            {
                for (int i = 0; i < wheelRotations.Length; i++)
                {
                    wheels[i].localRotation = Quaternion.Lerp(wheels[i].localRotation, wheelRotations[i], Time.deltaTime * 6.5f);
                }
            }
        }
    }
}

Vedhæft PUN2_CarSync-scriptet til "CarRoot"-objektet
Tilslut PhotonView-komponenten til "CarRoot"-objektet
I PUN2_CarSync tildeles SC_CarController-scriptet til Local Scripts-arrayet
I PUN2_CarSync tildel kameraet til Local Objects-array
Tildel WheelTransform-objekter til Wheels-arrayet
Tilslut endelig PUN2_CarSync-scriptet til arrayet Observerede komponenter i Photon View
Gem "CarRoot" objektet i Prefab og placer det i en mappe kaldet Ressourcer (dette er nødvendigt for at kunne skabe objekter over netværket)

3. Oprettelse af et spilniveau

Game Level er en scene, der indlæses efter tilslutning til rummet, hvor al handlingen finder sted.

Opret en ny Scene og kald den "Playground" (Eller hvis du vil beholde et andet navn, så sørg for at ændre navnet på denne linje PhotonNetwork.LoadLevel("Playground"); på PUN2_GameLobby.cs).

I mit tilfælde vil jeg bruge en simpel scene med et fly og nogle kuber:

Opret et nyt script og kald det PUN2_RoomController (Dette script vil håndtere logikken inde i rummet, som at skabe spillerne, vise spillerlisten osv.), og indsæt derefter koden nedenfor i det:

PUN2_RoomController.cs

using UnityEngine;
using Photon.Pun;

public class PUN2_RoomController : MonoBehaviourPunCallbacks
{

    //Player instance prefab, must be located in the Resources folder
    public GameObject playerPrefab;
    //Player spawn point
    public Transform[] spawnPoints;

    // Use this for initialization
    void Start()
    {
        //In case we started this demo with the wrong scene being active, simply load the menu scene
        if (PhotonNetwork.CurrentRoom == null)
        {
            Debug.Log("Is not in the room, returning back to Lobby");
            UnityEngine.SceneManagement.SceneManager.LoadScene("GameLobby");
            return;
        }

        //We're in a room. spawn a character for the local player. it gets synced by using PhotonNetwork.Instantiate
        PhotonNetwork.Instantiate(playerPrefab.name, spawnPoints[Random.Range(0, spawnPoints.Length - 1)].position, spawnPoints[Random.Range(0, spawnPoints.Length - 1)].rotation, 0);
    }

    void OnGUI()
    {
        if (PhotonNetwork.CurrentRoom == null)
            return;

        //Leave this Room
        if (GUI.Button(new Rect(5, 5, 125, 25), "Leave Room"))
        {
            PhotonNetwork.LeaveRoom();
        }

        //Show the Room name
        GUI.Label(new Rect(135, 5, 200, 25), PhotonNetwork.CurrentRoom.Name);

        //Show the list of the players connected to this Room
        for (int i = 0; i < PhotonNetwork.PlayerList.Length; i++)
        {
            //Show if this player is a Master Client. There can only be one Master Client per Room so use this to define the authoritative logic etc.)
            string isMasterClient = (PhotonNetwork.PlayerList[i].IsMasterClient ? ": MasterClient" : "");
            GUI.Label(new Rect(5, 35 + 30 * i, 200, 25), PhotonNetwork.PlayerList[i].NickName + isMasterClient);
        }
    }

    public override void OnLeftRoom()
    {
        //We have left the Room, return back to the GameLobby
        UnityEngine.SceneManagement.SceneManager.LoadScene("GameLobby");
    }
}