描述
Runtime Directory Watcher brings native Win32 file-system watching and async texture loading straight to Unreal Engine 5 Blueprints—with zero C++ required.
Watch any folder at runtime (including packaged builds) and react instantly to file additions, edits, deletions, and renames on the game thread. Seamlessly stream external images straight into UTexture2D without hitching your frame rate. Perfect for digital signage, virtual production, kiosks, hot-folder texture pipelines, and live modding.
Key Features
Watch Any Folder at Runtime
Supports absolute paths in PIE, Standalone, and packaged Win64 builds. Watch multiple directories simultaneously, each running on an isolated low-priority background thread.
4 Game-Thread Blueprint Events
Safely react to OnFileAdded, OnFileModified (with built-in 200ms debouncing), OnFileRemoved, and OnFileRenamed (delivers OldPath $\rightarrow$ NewPath). All events broadcast on the Game Thread, making them 100% safe for UMG and Actors.
Async Hot-Folder Texture Loader
LoadTextureFromFileAsync decodes PNG, JPG, and BMP files on a background thread pool via ImageWrapper, then generates transient UTexture2D assets on the game thread without causing frame hitches.
Copy-Safe File Loading
Includes an exclusive-open readiness check with automatic retries ($3 \times 100\text{ms}$). Files still being exported by Photoshop, Blender, or File Explorer are waited on rather than throwing instant load failures.
Overflow-Resilient Native I/O
Powered by native Win32 overlapped I/O (ReadDirectoryChangesW with a 64KB buffer)—never fragile polling. Features automatic resyncing on buffer overflow to prevent silent event loss.
Extension & Subtree Filtering
Case-insensitive wildcard filters (e.g., .png, .jpg, .) per watcher, with simple toggles to switch between top-level directory watching or recursive subfolder scanning.
Zero Setup Blueprint Subsystem
Built on UEngineSubsystem—automatically instanced with no Actors or Components to place in your scene. Access anywhere via Get Engine Subsystem.
Use Cases
Target WorkflowApplicationDigital Signage & Kiosks
Drop new graphics into a local folder; UMG slideshows update automatically without restarting the app.
Virtual Production / LED Walls
Art teams save assets directly from Photoshop or Substance; UE scene textures refresh instantly live on set.
Live Modding & UGC
Allow players to drop custom textures, skins, or audio files into a directory to populate in-game assets.
Hot-Reloading Data
Watch JSON or CSV config files to trigger live data parsing on OnFileModified.
Multi-Screen & Network Setups
Drive content dynamically across multiple machines via shared network folders.
Why Choose This Plugin?
Unreal Engine's built-in FDirectoryWatcher is editor-only and strictly C++.
Runtime Directory Watcher bridges this gap by providing a thin, high-performance C++ engine subsystem exposed 100% to Blueprints. It eliminates background polling loops in favor of low-overhead OS event notifications, delivering absolute reliability for shipping applications.
Dependency: None (Standalone Subsystem, native ImageWrapper integration)
Thread Safety: Multi-threaded I/O, main thread safety guaranteed via FTSTicker queue draining.
Quick Setup Guide (60 Seconds)
Enable the plugin in your project and restart the engine.
In any Blueprint, call Get Engine Subsystem $\rightarrow$ Runtime Directory Watcher Subsystem.
Call StartWatchingDirectory (specify your target path, e.g., C:/MyHotFolder, set Watch Subtree = true, and filter by *.png).
Bind your logic to OnFileAdded $\rightarrow$ LoadTextureFromFileAsync $\rightarrow$ Set Brush from Texture on your UMG Image.
Support & Community
Got questions or feature requests? Reach out directly via Facebook:
Documentation: https://docs.google.com/document/d/e/2PACX-1vT_PBFy4SQ3C_SF5HEu43qF_UtaQ1EIvqizWjmXdsC64MLzT17MXKXQCZUPqdim1zXTYQv9sfx9ERVw/pub