Module Loading - LCK Documentation

What Problem Does This Solve?

When integrating LCK into your Unreal project, you need to know:

Which modules to enable (core vs. optional)
Loading order (some modules must load before others)
Platform-specific modules (Windows vs. Android)
Audio plugin priorities (FMOD vs. Wwise vs. Unreal Audio)

This page explains module dependencies so you can configure your project correctly.

When to Read This

Read this when:

First-time LCK integration
Adding audio middleware (FMOD, Wwise, Vivox)
Troubleshooting module loading errors
Building for multiple platforms
Creating custom audio sources

Skip this if you’re just using the default tablet with UnrealAudio.

Module Hierarchy

LCKVulkan (EarliestPossible) ← Android Vulkan interop
    ↓
LCKCore (PostDefault) ← Recording subsystem
    ├── LCKAudio (PostDefault) ← Audio framework
    ├── LCKWindowsEncoder (PostDefault, Win64 only)
    ├── LCKAndroidEncoder (PostDefault, Android only)
    └── LCKAndroidGallery (PostDefault, Android only)
    ↓
LCKTablet (Default) ← High-level service
    └── LCKUI (Default) ← UI components
    ↓
Optional Audio Plugins (Default):
    ├── LCKFMOD
    ├── LCKWwise (Win64, Android)
    ├── LCKVivox
    └── LCKOboe (Android only)

Loading Phases Explained

Phase	When It Loads	What It’s For
`EarliestPossible`	Before engine init	Critical low-level systems (Vulkan interop)
`PostDefault`	After engine, before game	Core functionality (encoders, audio)
`Default`	Standard game module loading	UI, high-level systems, optional plugins

Never change LCKVulkan loading phase. It must load at EarliestPossible for Android Vulkan interop to work. Changing it will break Quest recording.

Core Modules (Required)

LCKCore

Phase: PostDefault
Platforms: All
What it does:

ULCKRecorderSubsystem — Low-level recording control
ULCKTelemetrySubsystem — Analytics
ULCKDeveloperSettings — Project configuration
Encoder factory interface

Dependencies: None (base module) When to use: Always required. This is the foundation.

LCKAudio

Phase: PostDefault
Platforms: All
What it does:

ILCKAudioSource interface
FLCKAudioMix for combining sources
Audio channel management

Dependencies: LCKCore When to use: Always required if you want audio in recordings.

LCKTablet

Phase: Default
Platforms: All
What it does:

ULCKSubsystem — World subsystem
ULCKService — High-level recording API
ALCKTablet — Tablet actor
ULCKTabletDataModel — State management

Dependencies: LCKCore, LCKUI When to use: Use this unless you’re building completely custom UI. Most developers want this.

LCKUI

Phase: Default
Platforms: All
What it does:

ULCKButton — Interactive 3D buttons
ULCKSlider — Slider controls
Recording state visualization

Dependencies: LCKCore When to use: Use if you want 3D UI components (buttons, sliders) in your world.

Platform-Specific Modules

Platform-specific modules are automatically loaded by LCK. You don’t need to manually enable them in your .Build.cs file.

Windows Only

LCKWindowsEncoder

Phase: PostDefault
Platforms: Win64
What it does: Windows Media Foundation encoder (H.264, AAC, MP4) Technologies:

IMFSinkWriter for muxing
IMFTransform for H.264 encoding
Direct3D 11 texture interop

Auto-loaded: Yes (on Windows builds)

Android Only

LCKAndroidEncoder

Phase: PostDefault
Platforms: Android
What it does: NDK MediaCodec encoder (H.264, AAC, MP4) Technologies:

AMediaCodec for encoding
AMediaMuxer for MP4 container
Vulkan/EGL texture interop

Auto-loaded: Yes (on Android builds)

LCKAndroidGallery

Phase: PostDefault
Platforms: Android
What it does: Save recordings to Android gallery Features:

MediaStore integration
Gallery notifications
Scoped storage support

Auto-loaded: Yes (on Android builds)

LCKVulkan

Phase: EarliestPossible
Platforms: Android
What it does: Vulkan interop for Quest devices Critical: Must load before engine initialization Auto-loaded: Yes (on Android builds)

Optional Audio Plugins

Audio plugins are optional and must be manually enabled if you want to use them.

Audio Priority Order

When multiple audio plugins are available, LCK uses this priority for game audio:

LCKFMOD (highest priority)
LCKWwise
LCKUnrealAudio (built-in, always available)

Only ONE game audio source is active at a time. Microphone and voice chat can run alongside game audio.

LCKFMOD

Phase: Default
Platforms: Win64, Android
Requires: FMODStudio plugin
What it does: Capture FMOD game audio Features:

DSP-based capture from master bus
Zero-copy audio pipeline
Automatic FMOD detection

How to enable:

// YourGame.Build.cs
PublicDependencyModuleNames.Add("LCKFMOD");

LCKWwise

Phase: Default
Platforms: Win64, Android
Requires: Wwise plugin
What it does: Capture Wwise game audio Features:

Output capture callback
3rd-order ambisonic support
Stereo downmix

How to enable:

// YourGame.Build.cs
PublicDependencyModuleNames.Add("LCKWwise");

LCKVivox

Phase: Default
Platforms: All
Requires: VivoxCore plugin
What it does: Capture Vivox voice chat Features:

Microphone capture (outgoing voice)
Incoming voice capture (other players)
Thread-safe callbacks

How to enable:

// YourGame.Build.cs
PublicDependencyModuleNames.Add("LCKVivox");

LCKOboe (Android Low-Latency Mic)

Phase: Default
Platforms: Android only
What it does: Google Oboe microphone capture Features:

Low-latency audio input
AAudio/OpenSL ES abstraction
Optimized for Quest

How to enable:

// YourGame.Build.cs
if (Target.Platform == UnrealTargetPlatform.Android)
{
    PublicDependencyModuleNames.Add("LCKOboe");
}

Build.cs Configuration

Minimal Setup (Core Only)

// YourGame.Build.cs
public class YourGame : ModuleRules
{
    public YourGame(ReadOnlyTargetRules Target) : base(Target)
    {
        // Minimum required
        PublicDependencyModuleNames.AddRange(new string[] {
            "LCKCore"  // Recording subsystem
        });
    }
}

This gives you low-level recording via ULCKRecorderSubsystem. No UI, no service.

Standard Setup (With Tablet UI)

public class YourGame : ModuleRules
{
    public YourGame(ReadOnlyTargetRules Target) : base(Target)
    {
        PublicDependencyModuleNames.AddRange(new string[] {
            "LCKCore",    // Required
            "LCKTablet",  // High-level service
            "LCKUI"       // UI components
        });
    }
}

This gives you ULCKService and the default tablet actor. Recommended for most developers.

Full Setup (With Audio Middleware)

public class YourGame : ModuleRules
{
    public YourGame(ReadOnlyTargetRules Target) : base(Target)
    {
        PublicDependencyModuleNames.AddRange(new string[] {
            "LCKCore",
            "LCKTablet",
            "LCKUI"
        });
        
        // Optional: FMOD integration
        if (Target.Platform == UnrealTargetPlatform.Win64 ||
            Target.Platform == UnrealTargetPlatform.Android)
        {
            PublicDependencyModuleNames.Add("LCKFMOD");
        }
        
        // Optional: Vivox voice chat
        PublicDependencyModuleNames.Add("LCKVivox");
        
        // Optional: Android low-latency mic
        if (Target.Platform == UnrealTargetPlatform.Android)
        {
            PublicDependencyModuleNames.Add("LCKOboe");
        }
    }
}

Plugin Configuration (.uproject)

Basic Plugin Entry

{
  "Plugins": [
    {
      "Name": "LCK",
      "Enabled": true
    }
  ]
}

Optional Audio Plugins

{
  "Plugins": [
    {
      "Name": "LCK",
      "Enabled": true
    },
    {
      "Name": "LCKFMOD",
      "Enabled": true,
      "Optional": true,
      "SupportedTargetPlatforms": ["Win64", "Android"]
    },
    {
      "Name": "LCKWwise",
      "Enabled": true,
      "Optional": true,
      "SupportedTargetPlatforms": ["Win64", "Android"]
    }
  ]
}

Why Optional: true? If the plugin isn’t present (e.g., FMOD plugin not installed), the game will still launch without errors.

Checking Module Availability at Runtime

// Check if FMOD module is loaded
bool bFMODLoaded = FModuleManager::Get().IsModuleLoaded("LCKFMOD");

// Check if Wwise module is loaded
bool bWwiseLoaded = FModuleManager::Get().IsModuleLoaded("LCKWwise");

// Get all loaded audio plugins
ULCKDeveloperSettings* Settings = ULCKDeveloperSettings::Get();
TArray<FLCKAudioPluginInfo> LoadedPlugins = Settings->GetLoadedAudioPlugins();

for (const FLCKAudioPluginInfo& Plugin : LoadedPlugins)
{
    UE_LOG(LogLCK, Log, TEXT("Audio plugin loaded: %s (priority %d)"), 
        *Plugin.Name, Plugin.Priority);
}

Common Configurations

Quest VR Game (Android)

PublicDependencyModuleNames.AddRange(new string[] {
    "LCKCore",
    "LCKTablet",
    "LCKUI",
    "LCKOboe"  // Low-latency mic
});

Auto-loaded: LCKVulkan, LCKAndroidEncoder, LCKAndroidGallery

PC VR Game (Windows)

PublicDependencyModuleNames.AddRange(new string[] {
    "LCKCore",
    "LCKTablet",
    "LCKUI"
});

Auto-loaded: LCKWindowsEncoder

Cross-Platform with FMOD

PublicDependencyModuleNames.AddRange(new string[] {
    "LCKCore",
    "LCKTablet",
    "LCKUI",
    "LCKFMOD"
});

Multiplayer with Vivox Voice Chat

PublicDependencyModuleNames.AddRange(new string[] {
    "LCKCore",
    "LCKTablet",
    "LCKUI",
    "LCKVivox"  // Capture voice chat
});

Plugin Settings UI

LCK provides a visual plugin settings UI in Project Settings: Location: Project Settings → Plugins → LCK SDK → Audio Plugins

What you can configure:

Enable/disable audio plugins
Set audio priorities
View warnings when multiple game audio sources are enabled

If you enable multiple game audio plugins (e.g., FMOD + Wwise), LCK will show a warning. Only ONE will be active at runtime based on priority order.

Troubleshooting

”Module ‘LCKFMOD’ could not be found”

Problem: You enabled LCKFMOD but don’t have the FMOD plugin installed. Solution: Either install FMOD plugin, or remove LCKFMOD from your .Build.cs and set "Optional": true in .uproject.

”LCKVulkan failed to load on Android”

Problem: LCKVulkan loading phase was changed or Vulkan isn’t enabled. Solution:

Verify LCKVulkan loads at EarliestPossible (check plugin settings)
Enable Vulkan in Android Project Settings → Mobile → Vulkan

Multiple audio sources active

Problem: You have FMOD, Wwise, and UnrealAudio all enabled. Solution: Only ONE game audio source can be active. Check priority order or disable unused plugins.

Key Takeaways

Core is required — Always include LCKCore

Platform modules auto-load — Don’t manually enable LCKWindowsEncoder/LCKAndroidEncoder

Audio plugins are optional — Only add what you need (FMOD, Wwise, Vivox)

One game audio source — FMOD > Wwise > UnrealAudio priority

LCKVulkan must load early — Never change its loading phase

Architecture — System architecture overview
Audio Overview — Audio system details
Types & Structs — Data structures

​What Problem Does This Solve?

​When to Read This

​Module Hierarchy

​Loading Phases Explained

​Core Modules (Required)

​LCKCore

​LCKAudio

​LCKTablet

​LCKUI

​Platform-Specific Modules

​Windows Only

​LCKWindowsEncoder

​Android Only

​LCKAndroidEncoder

​LCKAndroidGallery

​LCKVulkan

​Optional Audio Plugins

​Audio Priority Order

​LCKFMOD

​LCKWwise

​LCKVivox

​LCKOboe (Android Low-Latency Mic)

​Build.cs Configuration

​Minimal Setup (Core Only)

​Standard Setup (With Tablet UI)

​Full Setup (With Audio Middleware)

​Plugin Configuration (.uproject)

​Basic Plugin Entry

​Optional Audio Plugins

​Checking Module Availability at Runtime

​Common Configurations

​Quest VR Game (Android)

​PC VR Game (Windows)

​Cross-Platform with FMOD

​Multiplayer with Vivox Voice Chat

​Plugin Settings UI

​Troubleshooting

​”Module ‘LCKFMOD’ could not be found”

​”LCKVulkan failed to load on Android”

​Multiple audio sources active

​Key Takeaways

​Related

What Problem Does This Solve?

When to Read This

Module Hierarchy

Loading Phases Explained

Core Modules (Required)

LCKCore

LCKAudio

LCKTablet

LCKUI

Platform-Specific Modules

Windows Only

LCKWindowsEncoder

Android Only

LCKAndroidEncoder

LCKAndroidGallery

LCKVulkan

Optional Audio Plugins

Audio Priority Order

LCKFMOD

LCKWwise

LCKVivox

LCKOboe (Android Low-Latency Mic)

Build.cs Configuration

Minimal Setup (Core Only)

Standard Setup (With Tablet UI)

Full Setup (With Audio Middleware)

Plugin Configuration (.uproject)

Basic Plugin Entry

Optional Audio Plugins

Checking Module Availability at Runtime

Common Configurations

Quest VR Game (Android)

PC VR Game (Windows)

Cross-Platform with FMOD

Multiplayer with Vivox Voice Chat

Plugin Settings UI

Troubleshooting

”Module ‘LCKFMOD’ could not be found”

”LCKVulkan failed to load on Android”

Multiple audio sources active

Key Takeaways

Related