Modular Horror System Documentation

The Modular Horror System (built with blueprints) is a flexible and highly customizable toolkit designed to help you kickstart your horror game development. This system includes essential features such as enemy AI, dynamic lighting, footstep sound effects, and camera effects. It also comes with a demo map to showcase each feature in action, allowing for a quick setup and understanding of how to integrate these mechanics into your own project.

Technical Details

UE Versions

Unreal Engine 5.6
Unreal Engine 5.7

Number of Blueprints

70+ Classes
14 Structures
4 Enums

Input

Keyboard and Mouse

Quick Start

Import the System: Import the Modular Horror System into your Unreal Engine 5.6 or 5.7 project
Open the Demo Map: Navigate to the demo map to see all systems in action
Review Blueprints: Each system is modular and can be used independently
Customize: Adjust configurable variables to match your game's needs

Blueprint Systems

BP_Light (Lighting Blueprint)

The lighting system allows for dynamic and flexible control of light properties, enabling a variety of horror lighting effects, such as flickering and changes in intensity.

Configurable Variables

Powered? (Boolean) - Toggle the light on or off
Intensity - Controls the brightness of the light
Radius - Defines the light's attenuation radius
Volumetric Intensity - Adjusts the volumetric fog contribution for atmospheric effects
Light Color - Easily change the light color via the variable
Light Sound - Play sounds such as buzzing or flickering noises with the light
Flicker (Boolean) - Toggle flickering behavior on or off
Flicker Duration (Min/Max) - Control the random flicker speed between the minimum and maximum duration to create a natural flicker effect

Usage

Place the BP_Light blueprint in your level
Adjust the configurable variables in the Details panel
Enable Flicker for dynamic horror lighting effects
Set Light Sound to add atmospheric audio cues

BP_AI (Enemy AI Blueprint)

This blueprint controls the enemy behavior, including vision, hearing, movement, and roaming capabilities. It also interacts with the player through noise detection and line of sight.

Configurable Variables

Can Roam? (Boolean) - Enable/disable the enemy's ability to roam around the environment randomly
Can Hear? (Boolean) - Toggle the enemy's ability to hear player noises
Can See? (Boolean) - Toggle the enemy's vision to detect the player
Speed - Controls how fast the enemy moves when patrolling or chasing the player
Roam Radius - Defines the roaming area size where the enemy can randomly patrol
Roam Wait Duration - Time between random roaming behavior for more natural movement patterns
Tracking Player? (Boolean) - Toggles when the enemy detects and follows the player
v0.9: dead - Dead state variable that prevents attacks once an enemy is marked as dead
v0.9: deathDuration - Configurable time before enemy is destroyed (if ragdoll is disabled)

Improvements (v0.9)

Improved Movement: Enhanced enemy AI movement and rotation behavior
Death Handling:
- Checks for ragdoll on death
- If enabled, enemy ragdolls
- If disabled, enemy is destroyed after deathDuration
Dead State: Prevents attacks once an enemy is marked as dead
Removed Debug Logic: Cleaned up debug code for better performance
Fixed Destruction: Resolved issue where AI was not being destroyed properly on death

Usage

Place BP_AI in your level
Configure detection settings (Can See, Can Hear)
Set Roam Radius to define patrol area
Adjust Speed based on your game's difficulty curve
Enable Tracking Player for chase sequences
v0.9: Configure death behavior (ragdoll vs. destruction) and set deathDuration if needed

BP_Trigger_OG (Original Trigger Blueprint)

The original trigger blueprint that supports basic overlap and interaction-based events for quick gameplay mechanics prototyping.

Key Features

Simple setup for overlaps and manual triggers
Supports basic actions like teleport, show/hide, sound, and widget display
Works well for linear sequences or prototyping

Configurable Variables

Player - The actor interacting with or triggering the event
Trigger Type (Enum) - Defines how the trigger activates (e.g., Overlap, Manual)
Event - The action that occurs (e.g., play sound, show widget)
Do Once? (Boolean) - If true, trigger runs only once
Did Leave (Boolean) - True if the player has exited the trigger zone
Show Box (Debug) (Boolean) - Displays a visible box for debugging
Widget Duration - Length of time the widget remains visible

Usage

Place BP_Trigger_OG in your level
Set Trigger Type (Overlap for automatic, Manual for scripted)
Configure the Event that should occur
Enable Do Once for one-time events
Use Show Box for debugging during development

BP_Trigger_New (New Trigger Blueprint)

An advanced version of the trigger system built to work seamlessly with the New Interaction System introduced in v0.2. This blueprint integrates interaction types like Use, and Knock, allowing for more immersive, reusable, and scalable gameplay logic.

Key Features

Compatible with all interaction types (Use, Knock, etc.)
Modular logic that allows triggers on interact—not just overlaps
Supports more complex conditions and public variables for designer flexibility
v0.9: Refactored event trigger logic - removed sequence nodes, replaced with clean, event-based execution for easier adding, adjusting, and removal of interactions

Additions (v0.9)

Blackout Event: New event trigger that targets existing BP lights
- Can be applied globally or filtered by specific light tags
- Useful for dramatic lighting effects and scares

Usage

Place BP_Trigger_New in your level
Configure interaction type (Use, Knock, etc.)
Set up conditions and events
Test with the player's interaction system
v0.9: Use the Blackout event to control multiple lights simultaneously

Note: Other trigger functions may be added in future updates, but the blueprint is created in a way for you to easily modify and extend.

BP_Footsteps (Footstep Sound System)

The BP_Footsteps system is responsible for playing footstep sounds based on the surface type the player is walking on. It traces the physical material of the surface beneath the player and plays the corresponding sound.

Current Sounds

Default - Played when no specific surface type is detected
Carpet - Played when the player walks on a carpet surface
Wood - Played when the player walks on a wooden surface
Tile - Played when the player walks on a tiled surface
Grass - Played when the player walks on a grassy surface

Adding New Sounds

Assign a new Physical Material to the desired mesh or surface in your project
Physical materials can be found or created in the folder: Materials > Footstep
Once the physical material is set, modify the BP_Footsteps blueprint to include the new sound logic for that material in the Switch on Physical Surface node

Usage

Ensure your level surfaces have Physical Materials assigned
The system automatically detects surface type and plays appropriate sounds
Add custom surfaces by creating new Physical Materials and updating the blueprint

BP_Flashlight (Flashlight Blueprint)

The BP_Flashlight system provides dynamic control over flashlight settings, ensuring customizable intensity, color, and range. It integrates directly into the player's camera for seamless usability.

Configurable Variables

Intensity - Controls the brightness of the flashlight
Color - Defines the flashlight's light color
Radius - Adjusts the attenuation radius (range) of the flashlight
Temperature - Alters the light's warmth/coolness for different atmospheres
Outer Cone - Controls the flashlight beam's spread angle
v0.9: aimHeight - Variable for adjusting held item positioning (e.g. flashlight in hand)

Improvements (v0.9)

New Animation: The player now visibly holds and aims the flashlight instead of it simply spawning as a light source
Camera Attachment: Flashlight light source is now attached to the camera for consistent alignment and movement
Improved Falloff: Enhanced flashlight falloff and shadow behavior
Refined Lighting: Stronger atmosphere with improved visual consistency
Fixed Auto Depth-of-Field: Hand/flashlight no longer blurred when using the flashlight
Fixed Crouching: Resolved flashlight animation issues while crouching

Usage

The flashlight is integrated into the player blueprint
Adjust variables in the BP_Flashlight component
Modify Intensity and Radius for different gameplay scenarios
Use Temperature to create different atmospheric moods
Adjust Outer Cone to control beam spread
v0.9: Use aimHeight to fine-tune the flashlight's position in the player's hand

Inventory System

The inventory system provides a clean horizontal inventory bar with fully modular item logic.

Included Items

🔦 Flashlight (battery-powered, fully animated)
🔋 Battery
🗝️ Key
📖 Journal (lore + alerts)
📷 Camera (Added light source)
💊 Painkillers
🔫 Pistol
🔨 Crowbar
🪛 Screwdriver

Features

Pickup, use, and description display
"Use" icon appears only when contextually valid
Interface-based functions for easy access
Blueprint child support for expansion
v0.9: Inventory can optionally open only if the player has items (toggleable with clear comment for easy enable/disable)
v0.9: Easy Starting Items setup (function + variables/structure) to quickly add/remove default inventory items
Stamina bar auto-hides until used, then hides again at full (v0.8)

Journal Alert System (v0.9)

Added an alert UI widget system for journal updates.

Journal triggers can optionally display a "Journal Updated" notification
Configurable duration input to automatically hide alerts after X seconds
Clean, non-intrusive UI feedback

Usage

Configure journal entries in your project
Set the alert duration (or disable if not needed)
Alerts will automatically appear when journal is updated

Interaction System

Interact with doors, radios, light switches, phones, weapons, tools, and puzzles.

Features

Crosshair-based interaction feedback
Pickup, use, move, and inspect objects
Item-locked interactions (keys, tools, camera)
Match-rotation puzzle support (e.g. frame alignment)
v0.9: Refactored BP_Interactable event trigger logic - removed sequence nodes, replaced with clean, event-based execution for easier adding, adjusting, and removal of interactions

Light Switches (v0.9)

Light switches now have reusable event trigger function hooks that use the same event trigger system as other interactables.

Event Triggers: Light switches can now trigger external actions (e.g. fans, props, or other systems)
Improved Functions: Enhanced light switch functions for better reliability
Performance: Improved performance and reliability of light switch interactions
Fixed: Resolved issue where light switches would play multiple sounds on initial use

Usage

Place a light switch in your level
Configure the event triggers in the Details panel
Connect to other systems (fans, props, etc.)
Test the interaction system

Weapons & Tools

New gameplay systems expand combat and puzzle mechanics.

Pistol

Hit detection with impact response
Bullet and shell casing spawning
Muzzle VFX, firing audio, and first-person animation

Crowbar

Swing-based melee system
v0.9: Improved swing detection
v0.9: Added variables: swingDistance and swingHitRadius for better control
Breakable object support

Screwdriver

Tool-based vent interactions
Directional screw removal

Equip Manager

New UnequipAll logic cleanly removes current items
Simplifies switching between tools and weapons

Lumen Integration

This project uses Lumen for advanced global illumination and reflections. Lumen is active by default, providing high-quality lighting and real-time global illumination without needing baked lighting. Ensure your system supports Lumen for the best performance and visual quality.

Additional Features

Audio Files: 100+ (Cues, Waves, Attenuations)
Camera Sway System: Immersive camera sway effect for enhanced realism and tension
Fog System: Showcases volumetric fog in action, providing visual examples for those unfamiliar with how to use volumetric fog effectively in their horror games

Additional Blueprints

BP_HiddenText (v0.9)

A new actor that uses a Text Render component to show or hide text based on event triggers.

Features

Shows or hides text based on event triggers
Enables contextual reveals (e.g. turning on a lamp reveals hidden text)
Perfect for environmental storytelling and clues

Usage

Place BP_HiddenText in your level
Configure the text content
Set up event triggers to show/hide the text
Use with light switches or other interactables for contextual reveals

BP_Fan (v0.9)

A new actor that supports on/off states and rotates when activated.

Features

Supports on/off states
Rotates when activated
Designed to be triggered via event systems (e.g. light switches)

Usage

Place BP_Fan in your level
Connect to event triggers (light switches, buttons, etc.)
Fan will rotate when activated

Materials & Assets

Materials (v0.9)

Wall and Doorframe Materials: Fully exposed parameters with world-aligned texture scaling (auto-scale, no visible seams)
Material Instances: Created for walls and doorframes for fast, non-destructive customization
Ceiling and Flooring Textures: New textures with fully parameterized materials
Ceiling and Flooring Material Instances: World-aligned texture scaling to eliminate visible tiling and hard seams

Meshes (v0.9)

Modular Wall Meshes: New wall pieces for level building
Modular Doorframe Meshes: New doorframe pieces for level building

Usage

Find materials in the Materials folder
Use material instances for quick customization without modifying base materials
World-aligned scaling automatically handles texture tiling
Use modular meshes for efficient level building

FAQ

How do I add custom footstep sounds?

Create a new Physical Material in Materials > Footstep
Assign it to your surface mesh
Open BP_Footsteps and add a new case to the Switch on Physical Surface node
Assign your sound to the new case

Can I use individual systems without importing everything?

Yes! The system is modular. You can use individual blueprints (BP_Light, BP_AI, etc.) without importing the entire system.

How do I customize the flashlight?

Adjust the configurable variables in the BP_Flashlight component:

Intensity for brightness
Radius for range
Temperature for color warmth
Outer Cone for beam spread

What's the difference between BP_Trigger_OG and BP_Trigger_New?

BP_Trigger_OG is the original trigger system for basic overlap events. BP_Trigger_New integrates with the Interaction System and supports Use, Knock, and other interaction types for more complex gameplay logic.

Support

Discord: Join our Discord server for community support
Documentation: This documentation is continuously updated
Video Tutorials: Coming soon

Future Updates

Future updates may be added to further expand the system, ensuring it can grow based on user feedback and new developments in horror game design.