ScavButtIO

BepInEx mod for Casualties Unknown Demo that makes compatible devices vibrate based on your in-game health state using the buttplug.io protocol.

Vibration output is synthesized from seven concurrent wave components driven by live player-state reads: heart rate, bleeding, pain, shock, horror, fibrillation, and cumulative trauma.

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What you need

1. Casualties Unknown Demo

Available free on Steam.

2. BepInEx 5.x

The modding framework the game runs on. If you got the game through Steam it may already be installed — check for a BepInEx/ folder in your game directory. If not, follow the BepInEx installation guide.

3. ScavLib API

A modding helper library for Casualties Unknown.

1. Download ScavLib API.dll from the ScavLib releases page.
2. Place it in <GameDir>/BepInEx/plugins/.

4. Intiface Central

The server that talks to your hardware.

1. Download and install Intiface Central.
2. Launch it before starting the game.
3. Connect your device in Intiface Central (it will be discovered automatically once the game tells it to scan).

5. A buttplug.io-compatible device

Any device supported by Buttplug.io. Vibrating toys, e-stim units, etc.

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Installation (pre-built release)

1. Download ScavButt.dll from the latest release.
2. Create the folder <GameDir>/BepInEx/plugins/ScavButt/.
3. Place ScavButt.dll inside it.
4. Launch Intiface Central and make sure your device is connected there.
5. Start the game. Open the in-game console (default: `) and run:

   butt connect
   butt scan
   

6. Vibration starts automatically as soon as a world loads.

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Usage

Run butt --help in the in-game console to see all commands:

butt <subcommand> [args...]
Subcommands:
  connect     - (Re)connect to Intiface Central
  disconnect  - Disconnect from Intiface Central
  scan        - Start scanning for devices
  stopscan    - Stop scanning for devices
  devices     - List connected devices and their capabilities
  stop        - Stop all devices immediately
  test        - Trigger a test pulse through the wave system (visible in viz, vibrates if connected)
  status      - Show connection state and device count
  viz         - Toggle the wave visualizer overlay  |  butt viz poll — toggle poll-window markers on the graph
  set         - Set a vibration setting  (butt set <key> <value>)
  settings    - List all vibration settings and their current values

Wave visualizer

butt viz opens a real-time oscilloscope overlay that shows all seven wave components and the final mixed output. Useful for demos and for tuning settings without needing a device connected.

butt viz           # toggle the oscilloscope overlay
butt viz poll      # overlay + green markers for each device flush
butt test          # fire a test pulse visible in the viz

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Configuration

Run butt set --help to see all tunable parameters:

Usage: butt set <key> <value>
 [global]
   enable                  Master on/off (true/false)
   intensity               Hardware intensity cap 0–100 (%); bypasses Lovense app limits
   scale                   Global waveform output scale 0.0–1.0 (pre-hardware)
   poll-hz                 Device command rate 1–60 Hz (real-time flush window; game-time sampling stays at 20 Hz)
   ff-threshold            Time.timeScale above which fast-forward behaviour activates (default 1.5)
   silence-ff              Silence vibrations entirely during fast-forward (true/false); false = dampened output instead
 [effects]
   heartbeat               Heartbeat component on/off
   bleed                   Bleed component on/off
   pain                    Pain/shock component on/off
   horror                  Horror component on/off
   fibril                  Fibrillation component on/off
   impact                  Impact transients on/off
   trauma                  Trauma component on/off
 [heartbeat]
   hr-low                  HR below this triggers bradycardia vibration (BPM)
   hr-high                 HR above this triggers tachycardia vibration (BPM)
   amp-brady               Bradycardia peak amplitude 0–1
   amp-tachy               Tachycardia peak amplitude 0–1
   amp-arrest              Cardiac arrest amplitude 0–1
 [bleed]
   bleed-onset             Bleed speed where vibration starts
   bleed-ceil              Bleed speed where amplitude reaches max
   bleed-max-amp           Max bleed amplitude 0–1 (cap so bleed never saturates alone)
 [amplitudes]
   pain-onset              Raw pain value where vibration starts (0–80; PAIN_MILD=10, PAIN_MODERATE=30)
   amp-pain                Pain/shock peak amplitude 0–1
   amp-horror              Horror peak amplitude 0–1
   amp-fibril              Fibrillation peak amplitude 0–1
   amp-trauma              Trauma peak amplitude 0–1

Set a value: butt set intensity 75 — query the current value: butt set intensity. All settings persist across sessions via BepInEx's config file (BepInEx/config/com.scavbutt.scavbutt.cfg).

Run butt settings to see every setting and its current value at once.

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Building from source

Prerequisites

• .NET SDK (any recent version — the project targets .NET Framework 4.8 but the SDK builds it fine)
• Casualties Unknown Demo installed via Steam
• ScavLib API.dll in <GameDir>/BepInEx/plugins/

Steps

1. Clone the repo:

   git clone https://github.com/SapporoKami/cu_butt.git
   cd cu_butt
   

2. Copy the game path template:

   cp ScavButt/GamePath.props.example ScavButt/GamePath.props
   

3. Edit ScavButt/GamePath.props and set <GamePath> to your actual install directory:

   <GamePath>C:\Program Files (x86)\Steam\steamapps\common\Casualties Unknown Demo</GamePath>
   

   On Linux:

   <GamePath>/home/yourname/.steam/steam/steamapps/common/Casualties Unknown Demo</GamePath>
   

4. Build:

   dotnet build ScavButt/ScavButt.csproj -c Release
   

5. The output is at ScavButt/bin/Release/ScavButt/ScavButt.dll. Copy it to <GameDir>/BepInEx/plugins/ScavButt/ScavButt.dll.

You can also pass the path directly without creating GamePath.props:

dotnet build ScavButt/ScavButt.csproj -c Release -p:GamePath="C:\...\Casualties Unknown Demo"

GamePath.props is gitignored and never committed — it stays local to your machine.

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How it works

Once connected, the mod polls player state at 20 Hz and synthesizes a vibration intensity from seven additive components:

Component	Driven by
Heartbeat	Heart rate & beat phase — intensifies during bradycardia, tachycardia, or cardiac arrest
Bleeding	Bleed speed & internal bleeding — slow sine wave that speeds up as blood loss worsens
Pain/Shock	Pain and shock level — constant buzz that scales from 5 Hz to 12 Hz with severity
Horror	Horror level — erratic frequency that random-walks between 1–8 Hz
Fibrillation	Ventricular fibrillation progress — high-frequency chaos (8–15 Hz)
Impact	Spike detection — short transient on sudden trauma events (bone breaks, dismemberment)
Trauma	Cumulative tissue damage — very slow 0.25 Hz background throb

Components are mixed, soft-normalized so the total never exceeds 1.0, and modulated by consciousness, opiates, and painkillers.

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License

MIT — see LICENSE.