User Guide

Purpose

NsSession gives multiplayer rooms with a 5-letter code, like KXQTP. The host opens a map and gets a code. A friend types the code and joins. A room is a Steam lobby when Steam runs, and a LAN session in other cases. When the nearby Steam search finds nothing, a second search looks in every region.

NsSession has no UI, no session browser, no player names, and no map setting. Your game gives the map, shows the status lines, closes its menus, and opens the title map after a leave.

Setup

1. Copy the NsSession folder into the Plugins folder of your project.
2. Open the project and enable NsSession in Edit > Plugins. It also enables OnlineSubsystem, OnlineSubsystemUtils, and SteamSockets.
3. For C++, add "NsSession" to the dependencies of your game module in Build.cs.
4. Restart the editor.

For Steam rooms, also do these steps:

1. Enable the engine plugin OnlineSubsystemSteam in your project.
2. Set up Steam and the Steam net driver in DefaultEngine.ini.
3. In DefaultEngine.ini, set the connection class of the Steam net driver:

[/Script/SteamSockets.SteamSocketsNetDriver]
NetConnectionClassName="/Script/NsSessionSteam.NsSteamNetConnection"

Steam rooms work on Win64 only. Other platforms use LAN rooms.

Quick Start

1. Make a widget with a Host button, a text box for the code, a Join button, and a status text.
2. In the widget graph, call Get Ns Session Subsystem.
3. On Host, call Host Room and pick your gameplay map in the Map pin.
4. On Join, call Join Room with the text of the code box.
5. On Event Construct, bind On Room Status. In the event, set the status text to Get Status Text of the status.
6. Show Get Room Code in the HUD of the host.
7. Set the Play In Editor options to 2 players and Play Standalone.
8. Press Play. Host on one window, and join with the code on the other.

In C++:

#include "NsSessionSubsystem.h"

// RoomMap is a TSoftObjectPtr<UWorld> property of the menu.
void UMyMenu::Host()
{
    UNsSessionSubsystem::Get(this)->HostRoom(RoomMap.ToSoftObjectPath());
}

void UMyMenu::Join(const FString& Code)
{
    UNsSessionSubsystem::Get(this)->JoinRoom(Code);
}

// Bound to OnRoomStatus. OnRoomStatus is a dynamic event, so this handler is a UFUNCTION.
void UMyMenu::HandleRoomStatus(const FNsRoomStatus& Status)
{
    StatusText->SetText(Status.GetDefaultText());
}

Common Tasks

Host a room

1. Call Host Room with the map of the room.
2. Read the return value. False means that the host did not start.

The subsystem makes a new code and opens the map as a listen server. After the map loads, it creates the session that carries the code. Blueprint shows two Host Room nodes. The node with a Map pin of type World gives a map picker.

Join a room

1. Call Join Room with the code that the player typed.
2. Bind On Room Status to show the progress.

The code is not case sensitive, and spaces at the start and end do not count. The join searches LAN and Steam at the same time, and joins the first room with the code.

Show the room code in the HUD

1. Call Get Room Code. It is empty when this machine is not in a room.
2. Call Get Room Network to show Lan or Steam.

Show the status

1. Bind On Room Status, or call Get Last Status Text each frame.
2. Read Failed of the status. True means that the host or the join stopped.

For your own text, read Status of the status and pick your own line. Get Status Text gives the default English line.

Close the menus when the room opens

1. Bind On Room Entered.
2. In the event, close the menus.

On Room Entered fires each time a map loads as a listen server or as a client.

Leave a room

1. Call Leave Room.
2. Open your title map.

Leave Room stops the searches and ends the session on this machine. It does not open another map.

Show why a player came back to the title

1. In the title menu, call Consume Last Failure.
2. When it returns true, show Get Status Text of the status.

It gives the failure of a lost connection (Host Left or Connection Failed) one time.

Test without Steam

1. Start the game with the -lanroom command line option.

Play In Editor always uses LAN. Each Play In Editor window has its own LAN session.

Join an address directly

1. Call Join Direct Address with an address, for example 127.0.0.1.

This is for tests. It uses no code and no session.

Settings

UNsSessionSubsystem reads these values from Config/DefaultGame.ini. They do not show in the editor.

[/Script/NsSession.NsSessionSubsystem]
GameTag=MyGame
MaxPlayers=6

Give each game its own GameTag when two games share one Steam app ID, such as the Spacewar test app.

Debug

The plugin has no console commands or console variables.

Troubleshooting

Limits

• One room for each game instance.
• No session browser. A player needs the code.
• Play In Editor and -lanroom always use LAN.
• Steam rooms and the worldwide search work on Win64 only.
• Leave Room does not open another map.

Contact

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