Light function does not work with volumetric fog when not compatible with light atlas

UE - Graphics Features - Mar 28, 2025

Light functions do not work as intended with volumetric fog when using clamped mask textures which are not compatible with the light function atlas. In light functions materials, when using any UV ...

Lighting Channels Do Not Function with 78+ Lights on Actor

UE - Graphics Features - Oct 20, 2017

Lighting channels do not function when the number of lights affecting actors is 79 or higher. Any number of lights that is 78 or fewer will honor lighting channel assignments. ...

Broken hair material with light function

UE - Graphics Features - Dec 19, 2024

Hair Materials do not react to Light Functions in the same way as other Materials. There is a visual difference between a Directional Light at 1 lux with no Light Function and a Directional Light at ...

Camera Position Node in Light Function Materials does not function once applied to a light

UE - Rendering Architecture - Materials - May 25, 2023

In the material editor, the preview will change with the camera position. Similar to [Link Removed] though the light will still emit when applied. Investigating Regression info ...

Incorrect Lighting With Exponential Height Fog And Light Function Atlas

UE - Graphics Features - Jul 29, 2024

There currently is a mismatch occurring when light function atlases are used in conjunction with exponential height fog. When the flag r.VolumetricFog.UsesLightFunctionAtlas is enabled, light shafts ...

Regression: "Object Position" node in Light Function materials did not compile up to UE 5.0. Starting with 5.1, it compiles but outputs garbage values

UE - Rendering Architecture - Materials - Aug 26, 2024

Up to UE 5.0, when the "Object Position" node is used in the Material Editor as part of a material with Light Function domain, attempting to compile the material results in the following error: "[SM ...

Light Function and World Position in 5.4

UE - Graphics Features - Nov 4, 2024

When rendering a Light Function into the Translucency Lighting Volume, the World Position Material Expression returns the position relative to the Camera (unrotated), not the World. This can be mor ...

Camera Position node does not work with Light Functions

UE - Graphics Features - Sep 9, 2020

When a Light Function material is applied to a light source, and after using a camera position node and plugging that node into the Emissive Color option there is no light being emitted from the lig ...

Light Functions displayed on Large Translucent Meshes cause rendering errors

UE - Graphics Features - Sep 14, 2015

Light Functions are stretching and flickering on large translucent surfaces. Translucents Surface:[Image Removed] Opaque Surface:[Image Removed] ...

Light Function Material with Volumetric Fog Causes Screen-Space Banding

UE - Graphics Features - Jul 12, 2018

With a light function being used on a light and volumetric fog enabled if you move the camera around it will cause screen-space banding at the edges of the screen. Found in 4.19 CL# 4033788, 4.20 P ...