MULTIPLAYER MOBILE GAMES (UNITY)

Transcription

1 MULTIPLAYER MOBILE GAMES (UNITY)

2 Hello! MY NAME IS NOAM GAT Tacticsoft We make strategy MMOs And you are?

3 1 MULTIPLAYER GAMES Definition and scope

4 A multiplayer game is a game played by multiple people - Captain Obvious

5 HOWEVER There are several criteria to distinguish between them, with technical consequences.

6 HOW DO THE PEOPLE PLAY THE SAME GAME? Local (Single Device) Network Badlands World of Warcraft King of the Opera Clash of Clans Hearthstone Fifa?

7 THIS (TECHNICAL) LECTURE IS ALL ABOUT NETWORKED Local Multiplayer is awesome IMO very unexplored territory But it is technically equivalent to a single player game

8 HOW OFTEN ARE PEOPLE UPDATED? Turn Based Real Time Chess World of Warcraft Hearthstone Quake King of the Opera Fifa Clash of Clans?

9 WHO RUNS THE WORLD? Clients (P2P) Servers Old games New games

10 WHY DID P2P ARCHITECTURES FALL OUT OF FASHION? Servers are cheaper Less connectivity issues (port forwarding etc) Easier to prevent cheating If one of the players has the authority, it is called a server.

11 2 MULTIPLAYER CHECKLIST Building blocks for most multiplayer games

12 MULTIPLAYER FLOW Lobby Match Conclusion

13 LOBBY Devices don t know about each other yet They come to a central place and get grouped to each other Not the most interesting of tasks Don t reinvent.

14 MULTIPLAYER FLOW Lobby Match Conclusion

15 MATCH One central entity (Server) is in charge of the PERSISTENT GAME STATE The clients send actions to it, it notifies everyone of changes to the world The server can be one of the clients.

16 PERSISTENT GAME STATE? The compact representation of the game s state. (The Model of MVC) Chess? Game board FPS? Player positions, stats The clients have to be able to build their perspective of the game from it.

17 SINGLE AUTHORITY FOR EACH OBJECT Make sure not to have two entities in charge of the same object Character owned by client Projectiled owned by server Environment simulated separately Multiple management causes desyncs, flickers and unnecessary overhead

18 ACTIONS AND CHANGES The client has to notify the server of its actions. It can do so in several ways: State updates (I am in X=1,Y=4) State deltas (I moved up) Actions (Jump) The client has to update from the server. Not always symmetric.

19 TRADEOFFS State Based Delta / Action Based Robust Secure Simple Compact Cheap

20 Lobby Game Conclusion

21 Conclusion In case of a metagame, server updates the bookkeeper of the match results. High scores Rankings XP The bookkeeper is often the lobby.

22 3 UNITY MULTIPLAYER Let's build stuff.

23 Many different possibilities WWW Class (HTTP requests) Legacy Unity Networking UNet (New in Unity 5.1) Asset Store (Photon, Parse etc)

24 Many different possibilities WWW Class (HTTP requests) Legacy Unity Networking UNet (New in Unity 5.1) Asset Store (Photon, Parse etc)

25 UNet

26 UNet Latest in-house evolution of Unity s networking efforts. Lets you select which GameObjects to synchronize, and how.

27 UNet (1 of 4) Create a NetworkManager. Select Offline (Lobby), online (Match) scenes and per-client Prefab. Debugging Lobby GUI

28 UNet (2 of 4) Create a NetworkIdentity. Decide who takes care of this network-synced object, and how data is transferred.

29 UNet (3 of 4) Manage objects. Enable / disable components based on whether the client controls this instance of a player.

30 UNet (4 of 4, optional) Manage sync. Smoothly transition between state snapshots rather than pop between them.

31 UNet Video Tutorials gamertogamedeveloper.com 21 episode long video tutorial of creating a project with UNet. Includes source code of final project!

32 Legacy Warning Legacy Unity Networking and UNet don t mix! Check documentation to make sure you are using consistent components.

33 Parse

34 Parse A Backend as a Service owned by facebook. Not created just for game development, but is useful in this domain.

35 Parse (1 of 3) Create objects.

36 Parse (2 of 3) Retrieve objects (from the same client or others).

37 Parse (3 of 3) Query objects (from the same client or others).

38 Parse A simpler and slightly less Unityish solution. If you can define your multiplayer layer as database interactions, this is be a very simple way to approach it.

39 Parse Very well documented SDK. Costs money to scale up, but has a generous free offer that you won t pass until you have MANY users.

40 4 HACKATHON TIPS Let's build stuff.

41 AIM FOR THE SUNNY SCENARIO Robust multiplayer handling is hard. Assume everything with the connection is fine.

42 FORGET ABOUT SECURITY / CHEATING Its OK to give clients more than they need to know if it makes things easier for you. For now.

43 GET THE NETWORKING POC DONE QUICK Think of the solution that suits your game. Get to a point where two clients share data ASAP.

44 LOVE THY NEIGHBOUR You will share similar difficulties with the other groups. Use the power of the group to solve things faster.

45 Thanks! ANY QUESTIONS? You can find me