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 ...

ISM + WPO = broken motion vectors?

UE - Graphics Features - Nov 5, 2024

Instanced Static Meshes will have incorrect velocity if a Material uses World Position Offset. Fixed WPO in a material causes significant velocity on the ISM. This was also replicated in //UE5/Rele ...

Global SkyAtmosphere and Clouds Issues (Cloud Shadows)

UE - Rendering - Graphics Features - Dec 3, 2024

Sampling Cloud Shadows when rendering the Sky Atmosphere can incorrectly assume that the view is located at the planet's North Pole. This causes distortion in the shadows when using a sphere-shaped ...

Global SkyAtmosphere and Clouds Issues (Ambient Light)

UE - Rendering - Graphics Features - Dec 3, 2024

Ambient Light on Volumetric Clouds from Sky Atmosphere always is calculated as if the clouds are at the north pole of the planet. Using a sphere-shaped Sky Atmosphere and Volumetric Clouds causes t ...

r.Lumen.Reflections.DownsampleFactor split screen artifact

UE - Graphics Features - Lumen - Dec 6, 2024

In Split-Screen, with "r.Lumen.Reflections.DownsampleFactor" set to 2, it is possible to have vertical colored artifacts on View 1 (the second view). The Licensee reported the artifact occurred on ...

Contact shadows bug in splitscreen

UE - Graphics Features - Dec 11, 2024

Screen Space shadows do not check the view boundary. This can cause extra shadows in split screen, as one view can cast shadows in another view. ...

Substrate SSR reflections are black

UE - Graphics Features - Substrate - Dec 17, 2024

Substrate Materials do not use Screen-Space reflections. Instead, they do not have any reflections (indirect specular) on the surface. ...

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 ...

Water body actor casts static shadow

UE - Graphics Tools - Terrain - Water - Jan 14, 2025

WaterBody Actors will cast static shadows in built lighting even if their Cast Shadow options are disabled. ...

[Interchange][FBX] Bone orientation is different between legacy and interchange import with the ForceFrontXAxis

UE - Editor - Content Pipeline - Import and Export - Jan 16, 2025

When importing FBX files using the Interchange and legacy import with Force Front X Axis enabled, the transforms of the bones in the imported FBX models will not match. ...