ScarCore Communication System

What you get

ScarCore Communication System adds working multiplayer communication to your game: server-authoritative text chat, voice chat with push-to-talk, adjustable voice volume (master, per-player and mic gain), a quick-messages panel, a per-player mute list, and a live ping readout. You add one component to your PlayerController and press Play. That is the whole setup.

Everything is Blueprint-friendly and nothing is hard-coded to a platform. Your DefaultEngine.ini decides whether you are on Steam, EOS, LAN or a dedicated server, and the plugin adapts to whatever it finds.

Quick start

1. 01Install and enable. In the Epic Games Launcher, install the plugin to your engine version (4.27 to 5.7) from your Fab Library. Then in your project: Edit > Plugins, search "ScarCore", tick Enabled, restart.
2. 02Add the component. Open your PlayerController Blueprint, click Add Component, and add ScarCore Communication Component.
3. 03Pick the UI. Select the component and set Main Widget Class to ScarCoreBaseUI.
4. 04Set up your platform in one click. Open Edit > Project Settings > ScarCore Communication, pick Target Platform (Steam / EOS / Local / Null), and click Apply Platform Config. It writes the DefaultEngine.ini entries for you, online subsystem plus voice. Restart the editor.

Local / Null needs no credentials. It is the one to pick for LAN, dedicated servers, direct-IP and single-machine standalone testing.

Press Play with 2 or more players on a listen server. You see the chat panel bottom-left, mic and speaker buttons above it, and the ping top-right. Press Enter to type, M to turn your mic on, hold V to talk, and N to hear everyone else.

Online subsystem config

The fast way is Project Settings > ScarCore Communication > Apply Platform Config, which writes all of this for you. The blocks below are the manual equivalent and a reference for exactly what gets written. Put your chosen block in YourProject/Config/DefaultEngine.ini and restart the editor, since Unreal loads the subsystem once at startup.

LAN / local testing (Null)

[Voice]
bEnabled=true

[OnlineSubsystem]
bHasVoiceEnabled=true
DefaultPlatformService=Null

Steam

Enable the Online Subsystem Steam plugin in Edit > Plugins first, and have the Steam client running when you test.

[Voice]
bEnabled=true

[OnlineSubsystem]
bHasVoiceEnabled=true
DefaultPlatformService=Steam

[OnlineSubsystemSteam]
bEnabled=true
SteamDevAppId=480
GameServerQueryPort=27015
bRelaunchInSteam=false
bVACEnabled=false

[/Script/OnlineSubsystemSteam.SteamNetDriver]
NetConnectionClassName="OnlineSubsystemSteam.SteamNetConnection"

[/Script/Engine.GameEngine]
!NetDriverDefinitions=ClearArray
+NetDriverDefinitions=(DefName="GameNetDriver",DriverClassName="OnlineSubsystemSteam.SteamNetDriver",DriverClassNameFallback="OnlineSubsystemUtils.IpNetDriver")

Epic Online Services (EOS)

Enable the Online Subsystem EOS plugin, create an artifact at dev.epicgames.com/portal, and fill in your own ids. The encryption key must be exactly 64 hex characters.

[Voice]
bEnabled=true

[OnlineSubsystem]
bHasVoiceEnabled=true
DefaultPlatformService=EOS

[OnlineSubsystemEOS]
bEnabled=true

[/Script/OnlineSubsystemEOS.NetDriverEOS]
bIsUsingP2PSockets=true

[/Script/Engine.GameEngine]
!NetDriverDefinitions=ClearArray
+NetDriverDefinitions=(DefName="GameNetDriver",DriverClassName="OnlineSubsystemEOS.NetDriverEOS",DriverClassNameFallback="OnlineSubsystemUtils.IpNetDriver")

[/Script/OnlineSubsystemEOS.EOSSettings]
DefaultArtifactName=DefaultArtifact
bEnableOverlay=true
bEnableSocialOverlay=true
bUseEAS=true
bUseEOSConnect=true
bUseEOSSessions=true
+Artifacts=(ArtifactName="DefaultArtifact",ClientId="<id>",ClientSecret="<secret>",ProductId="<id>",SandboxId="<id>",DeploymentId="<id>",EncryptionKey="<64-hex-chars>")

Dedicated servers (optional tuning)

No special setup is needed. The component detects dedicated servers and runs no UI or timers there. Voice works on dedicated and direct-IP servers by default, because the custom relay sends compressed frames over the game connection, so no OnlineSubsystem session is required. The values below are just sensible network tuning.

[/Script/OnlineSubsystemUtils.IpNetDriver]
NetServerMaxTickRate=60
MaxClientRate=30000
MaxInternetClientRate=30000

[/Script/Engine.GameSession]
MaxPlayers=64

Mic sensitivity (optional)

[Voice]
SilenceDetectionThreshold=0.01
MicNoiseGateThreshold=0.01
MicInputGain=1.0
MicOutputGain=1.0

Mobile permissions (only if you ship there)

; Android - DefaultEngine.ini
[/Script/AndroidRuntimeSettings.AndroidRuntimeSettings]
+ExtraPermissions=android.permission.RECORD_AUDIO
+ExtraPermissions=android.permission.MODIFY_AUDIO_SETTINGS
+ExtraPermissions=android.permission.INTERNET
+ExtraPermissions=android.permission.ACCESS_NETWORK_STATE

; iOS - DefaultEngine.ini
[/Script/IOSRuntimeSettings.IOSRuntimeSettings]
AdditionalPlistData=<key>NSMicrophoneUsageDescription</key><string>Voice chat with other players.</string>

Default controls

The widget binds these keys on its own, with no Project Settings > Input work and no Blueprint wiring. Every key is a property under the widget Class Defaults (ScarCore | Input | Auto-Bindings) if you want different ones, and Auto Register Key Bindings = false turns the whole thing off so you can wire your own.

The settings you will actually touch

Everything lives on the component, in the Details panel under the ScarCore categories. These are the ones that matter day-to-day. The rest, such as colours, rate limits and UI visibility toggles, are right next to them and self-explanatory.

Build your own UI

Design a normal Widget Blueprint with any layout, art and animations you want. The plugin finds its widgets by name and wires them up automatically.

1. 01Content Browser > right-click > User Interface > Widget Blueprint, and pick ScarCoreCommunicationWidget as the parent class. For an existing WBP, open it and use File > Reparent Blueprint.
2. 02Design your layout. Wherever a feature should live, add the matching widget from the table below and rename it to the exact name shown.
3. 03Tick Is Variable on each of those widgets, at the top of the Details panel.
4. 04On the component, set Main Widget Class to your new widget. Chat, voice, popups and key bindings all work in your layout.

The named widgets

A layout that works

Canvas Panel
  ChatPanel            Vertical Box      bottom-left
    ChatScrollBox      Scroll Box
    HorizontalBox
      ChatInputTextBox Editable Text Box
      SendButton       Button
  VoicePanel           Horizontal Box    above the chat
    MicButton          Button
    SpeakerButton      Button
  PingTextBlock        Text Block        top-right
  QuickMessagesPanel   Vertical Box      centered, Collapsed
  PlayerListContainer  Border            right side, Collapsed
    PlayerListPanel    Vertical Box
  OpenPlayerListButton Button            near the voice row

Icons and styling

In your widget Class Defaults you will find texture slots for every state: Mic On / Off Icon, Speaker On / Off Icon, icons for the open-list button, and per-row speaker icons for the mute list. Assign a texture and the plugin stamps it onto the button whenever the state changes, with hover and pressed tints applied for free. One texture per state is enough. Leave a slot empty to keep whatever brush you designed.

Custom popup rows

• Quick messages: make a WBP with parent ScarQuickMessageRow, add a Button named RowButton and a Text Block named RowLabel, then set Quick Message Row Class on your main widget.
• Mute list: make a WBP with parent ScarPlayerMuteRow, add a Button named MuteButton and a Text Block named NameText, then set Player Mute Row Class.

Animation hooks

Four events fire on your widget so you can play UMG animations: BP On Player List Show / Hide Requested when Tab opens or closes the mute list, and BP On Chat UI Hide / Show Requested when Escape hides the chat and Enter brings it back. Visibility and the mouse cursor are already handled by the time they fire, so the animation is pure polish.

Quick messages and the mute list

Quick messages

Canned phrases players send without typing. Fill the Quick Messages array in your widget Class Defaults, one entry per row, in order. In game: C opens the panel, Up and Down pick, Enter sends, Escape closes. Messages go through the normal chat pipeline, filter and rate limit included. The panel auto-closes after sending and shows the mouse cursor while open, both configurable.

Per-player mute list

Tab opens a roster of every other player in the session with a speaker icon per row. Click to mute or unmute that player locally. The muted player is not notified, nobody else is affected, and the choice sticks for the whole match, even across a reconnect. The list refreshes itself every second while open, and works on clients as well as the host.

From Blueprint, Mute Player, Is Player Muted and Get Active Remote Voice Players on the component let you build the same feature into your own scoreboard instead.

Blueprint API

Component functions

Widget functions

Events

Five-minute recipes

• Welcome message: PlayerController BeginPlay, branch Is Local Player Controller, Delay 0.5s, then Add Local Message with sender "System".
• Server announcement: a Run-on-Server event that calls Send Chat Message Colored with your announcement colour.
• Mute checkbox in your settings menu: checked = Hard Mute Mic, unchecked = Unhard Mute Mic.
• Talking indicator over heads: override On Remote Player Talking Changed, find the matching PlayerState in the GameState Player Array, and toggle an icon on their pawn.
• Mute from your scoreboard: Get Active Remote Voice Players for the roster, Is Player Muted for current state, and Mute Player on your button.
• Ping in your own HUD: a 1s timer that calls Get Current Ping Ms and writes it to your text block.
• Voice volume slider: drop a Slider named VoiceVolumeSlider (Min 0, Max 1) into your widget and it auto-controls master voice volume with no wiring. For a settings menu, bind your own slider On Value Changed to Set Voice Output Volume instead.
• Per-player volume: build a row list from Get Active Remote Voice Players, give each row a slider, and call Set Player Voice Volume with the player id and value. Use Set Mic Input Gain for the player own transmit level.

Test it, then ship it

Testing chat and voice on one PC

Play dropdown > Number of Players = 2, Net Mode = Play As Listen Server. For chat, keeping Run Under One Process is fine: type in one window and watch it in both. For voice, untick Run Under One Process so each player is its own standalone process, since they would otherwise share one audio session.

Both windows share your single mic, so split the roles: in the host window press M for mic on, and in the client window press N for speaker on. Talk, and the client plays your voice back. With Use Push To Talk off, M and N behave like a normal game. With it on, hold V to talk.

Shipping checklist

• DefaultEngine.ini has the voice block plus your platform block.
• Steam: real App ID (not 480) and the Online Subsystem Steam plugin enabled.
• EOS: real artifact ids and a 64-character hex encryption key.
• Component on the PlayerController your shipped GameMode actually uses, with Main Widget Class set.
• Custom UI: parent class is ScarCoreCommunicationWidget, named widgets spelled exactly, Is Variable ticked.
• Startup states reviewed: Start With Mic On and Start With Speaker Muted match your design.
• Voice path chosen: Use Custom Voice Relay stays ON for dedicated and direct-IP servers; flip OFF only for session-based OSS voice. Debug Voice Loopback is OFF.
• Blocked Words filled with a real list, and Quick Messages filled if you use the panel.
• Default keys do not clash with your game bindings; rebind in Class Defaults if they do.
• Mic permissions added for Android and iOS if you ship there.
• One Shipping build, two real players, chat and voice confirmed.

When something is off

License and support

You can use the plugin in unlimited personal and commercial games, customise it through Blueprint children, and ship it inside your packaged game on any platform.

You cannot resell or redistribute the plugin itself, upload it anywhere, or bundle it in tools or asset packs meant for other developers.