Steamworks Matchmaking and UE4 Online Subsystem (Matchmaking not supported?)

Pikkukatit · February 13, 2015, 9:39am

So after being Greenlit we started working on Matchmaking for our game using the Steamworks API and the Unreal Engine Online Subsystem. There isn’t much documentation available for it and we have now run into some issues that haven’t really been documented well and searching for answers yielded no results.

So we tried implementing the it through the Online Subsystem and it simply didn’t work, so we took a look at the Source in GitHub. We found the OnlineSessionInterfaceSteam.cpp and all we could find for Steamworks Matchmaking was that the function StartMatchmaking only has a log call “Matchmaking is not supported on this platform.” and it always returns false. So is the Steam Matchmaking simply not supported at this point (contradicting the Online Subsystem Steam | Unreal Engine Documentation Steam documentation) or is worked on or did we just do it properly?

We also found that some aspects of the Leaderboard system is lacking as well; in the file OnlineLeaderboardInterfaceSteam.cpp function WriteOnlinePlayerRatings does nothing.

So have we just misunderstood something or are these aspects something that are not supported (will there be support?)?

Pikkukatit · February 15, 2015, 1:31pm

Bumping this. There is almost no documentation so we really have no clue on what is the problem if it’s supported and if it’s not an answer on the future of Steamworks support from Epic would be greatly appreciated.

Pikkukatit · February 19, 2015, 8:09am

Bumpity bump. Answers ticket can be found here if someone else is facing the same issues and wants to upvote: Steamworks Matchmaking with UE4 OnlineSubsystem not supported? - Platform & Builds - Unreal Engine Forums

Stephen_Ellis · February 19, 2015, 6:17pm

Hi Pikkukatit,

I spoke with one of our engineers about this, and he will reply to the AnswerHub post as soon as he is able.

>Steamworks Matchmaking with UE4 OnlineSubsystem not supported? - Platform & Builds - Unreal Engine Forums

Cheers

Pikkukatit · February 20, 2015, 7:43am

Thank you, Stephen, we got it working now and matchmaking is live

I’ll quote his answer here in case someone stumbles here, but you can lock the thread if you want to:

Sorry for the confusion and apologies for lack of documentation.

The StartMatchmaking function is an Xbox LIVE specific function that has no analogue on Steam.

Steam works with matchmaking as long as you use the Sessions APIs and the Create/Destroy/Update/JoinSession calls.

Looking at the ShooterGame example, you should be able to see how sessions are created/updated/destroyed by a server and how they are found/joined by a client. There is also Start/EndSession, but that is not quite as important on the Steam platform.

When you create the session settings and set FOnlineSessionSettings::bUsesPresence=true, you will use Valve’s lobby APIs. If this is false, you will be using Valve’s GameServer APIs. Lobbies give you free authentication and also access to their newer/more straightforward matchmaking APIs. However, the GameServer APIs are required if you plan to do standalone dedicated servers. I would suggest you go the lobby route for now as it is newer and should save you some time.

Specific Steam implementations are found in

OnlineSessionAsyncLobby.h/.cpp

OnlineSessionAsyncServer.h/.cpp

As for leaderboards, again I believe WriteOnlinePlayerRatings was some function written for one of the console platforms that may not have an analogue in Steam, or if it does, wasn’t implemented. That being said, leaderboards still should work without this. The function WriteLeaderboards should do what you want.