LXR - Light Detection

ClusterFact Games - Code Plugins - Nov 13, 2021

LXR is highly optimized plugin for detecting if actor is illuminated and how much and which color illuminance actor receives.

  • Supported Platforms
  • Supported Engine Versions
    4.26 - 4.27, 5.0
  • Download Type
    Engine Plugin
    This product contains a code plugin, complete with pre-built binaries and all its source code that integrates with Unreal Engine, which can be installed to an engine version of your choice then enabled on a per-project basis.

| Discord | Documentation | Example Project |

v1.3 LXR : Ultimate Light Detection - Not just Detection!

  • A lot of optimizations.
  • Light Sense system enables actors to "see" light.
  • Actors can remember state of light with the new Light Memory system.
  • New Documentation articles, guides, setup, examples.

v1.2 LXR : Ultimate Light Detection - Just Got Better!

  • A lot of optimizations.
  • New Octree based relevancy detection
  • A lot of helper functions to make different gameplay based on light color
  • New awesome Documentation page.

LXR : Ultimate Light Detection

LXR is a highly optimized plugin for detecting if an actor is visible to a light source as well as to what degree they are lit, and which color the actor receives.

LXR is a multi-threaded and tick-optimized performant solution, even when multiple light sources are present.

LXR dynamically optimizes check interval based on the subject's distance to light sources.

LXR Supports all unreal dynamic light types: point, spot, rect and directional lights.

The plugin calculates illuminance (lux) an actor receives based on physically-based lighting using the same math that Unreal uses for rendering illuminance.

Although LXR uses Unreal's own equations for calculating illuminance, the final illuminance calculated by LXR is still an approximation.

LXR is Smart, Fast and Easy.


Dynamically optimizes check interval based on distance to light source.


LXR is optimized to the bone.

Multithread ensures blazingly fast checks even in extreme conditions.

Smart mode makes sure that CPU time is allocated where it's needed.

Octree mode to only check nearby relevant lights.


LXR extremely easy to use.

One component for detecting one component for light sources.

Known issues:

  • For now LXR does not calculate illuminance from static lighting but I am researching a feasible way to do that.
  • Detection of rectlights is not perfect, yet!

For more information head to LXR Documentation

Technical Details


  • Light detection
  • Smart
  • Fast
  • Easy

Code Modules:

  •  LXR, Runtime 

Number of Blueprints: 1 : Debug widget for Illuminance.

Number of C++ Classes: 4

Supported Development Platforms: Windows

Supported Target Build Platforms: Windows

Support : Discord link

Documentation: Documentation

Example Project: Here (Unreal 5)

Pre-build projects: Showcase / Example