Creating a multiplayer game where the players are on different maps.

[anonymous_user_3311af6b]

Hey there.

I am starting a new project. I am wondering if anyone knows of a way (through blueprint or c++) that I could have a LAN game going, where the players are sending data to each other, but are on different maps.

So, the first player could be looking at a battlemap, for example, and influencing things that happen in the game world for the other players in the match.

Any ideas?

[anonymous_user_73746a831 (anonymous_user_73746a83)]

I made a post here with a general idea of this. You’ll have to add some custom networking code.

@zerosum0x0;507784

The network documentation is still sort of fragmented and incomplete, even among the high level details of it. You’ll probably have to analyze source and packet captures. Cheating communities might be a source for documentation, haven’t looked into it though.

I think the default network now supports more than 64 players (or it has always been a rumour), not sure about multiple maps though. There’s a MMO framework for sale, which stress tested 100+ players, but it’s all in blueprints and only had 1 map I think.

If it doesn’t support multiple maps, you can maybe do seamless travel. If you do decide to roll your own RPC and replication, I suggest ENet, it’s a great reliable/unreliable channel-based cross-platform UDP library with a permissive MIT license. You might have to hack the engine for multi-map support, but for replication you can probably create a custom actor to inherit everything from. But yea, the default network library really only seems scoped to match-based games like FPS and MOBAs (at least from what I can tell).

Just had an epiphany: I’m 90% sure you can easily do MMO style multi-zones with Unreal default networking. Each zone/map you just have an Unreal server on a different static DNS/IP or port listening. When a player zones, you network travel to that particular zone/map server IP/port. You can also set up a world server that these zone servers intercommunicate with outside of Unreal’s networking, which would let you do things like global chat. Hell, you could even keep an open connection to the world server on clients, but again that’d be outside of Unreal’s networking (again, ENet would shine here).

This is basically the design of EverQuest, which had a login server where after authenticating you were passed a packet with all the realm/world servers. You picked one and connected to it. After selecting a character, you were sent a packet with your character’s current zone port. When you zoned, you were given a packet with the new port. The world server also spawned and closed the zone servers as needed to free resources (i.e. no ones in a zone, bring it down. need an instance? spawn a zone server).

Depending on the goal, you could do this with one giant map and areas that aren’t connected.

[anonymous_user_7e341a86]

hmm very interesting! Thanks for the response. The post was very valuable.

The thing I’m worried about is:
if I have a detailed scene with lots of 3d stuff happening, and then on the same map have just a simple UI that is capable of running on tablets and smart phones, will the tablet/smartphone instance of the game incur a performance hit because of the things happening else where on the map, even if they are not rendering all that stuff?

Also worried about application size here - ideally the mobile version that has the strategic view would not even need to store all the 3d graphic resources used by the desktop version of the game. Ideally, the desktop ‘host’ version of the game will not need to take into account the fact that the game is also running on mobile. This is another reason for wanting to do multiple maps.

The mobile versions of this game will only need to use RPC’s to send messages to the desktop ‘host’- they won’t need to do any synchronous as the game will be turn based.
Hope the rest of this info helps/

[CreatureNZ]

You can do this in C++ but it isn’t particularly straight forward. If you look in to the engine code for the Beacon system, specifically the party beacon objects you will find a way of opening connections between users.

[thevfxguy13]

Would Level Streaming be helpful in this case?

[Starkium]

sorry to necro, but curious about expanding upon the above. What if there is a container map that has an actor that passes the logic back and forth and for each client you either spawn sub map for the 3d or simple map for the mobile and do communication that way

I Image it would be kind of a pain if scale was different. I have a case that I am looking into for my own project where a VR player is large over a small version of the map the other non vr players play in. So I think what would happen in my case if that the movements of the non VR players would be scaled or something and then sent to vr player where tiny instances of the non vr characters move on the tiny map. This gets even more weird when considering I want the vr player to drop ai onto the map in his world that end up spawning in the non vr world. As far as handling the AI stuff and character interactions I think using something like GAS would probably do the trick for handling that, but geez IDK about how I’m going to scale the movement properly. Seems like an odd scenario

[BrUnO_XaVIeR]

Actors only spawn to the persistent world.
Player connections exist in the persistent map, streamed levels won’t affect connections.