Nanite Skeletal Mesh uses incorrect LOD for raytracing

UE - Graphics Features - Nanite - Jan 13, 2025

LOD0 for some Nanite Skeletal meshes is used for ray tracing scenes on some platforms  because some FSkinnedSceneProxy are incorrectly considered "always visible" ...

GPU Crash from invalid SRV in CreateShaderResourceView due to integer underflow

UE - Graphics Features - Ray Tracing - Jan 13, 2025

The GPU crashes after the ray tracing geometry builder attempts to create a shader resource view with an invalid offset. ...

Building Geometry Stops UTickableWorldSubsystem Ticking

UE - Gameplay - Jan 13, 2025

Can be mitigated by reopening the Level. There is a repro project provided by the licensee on the case ticket. ...

[Interchange][FBX] Fail to import attributes animation curves with key values as integer

UE - Editor - Content Pipeline - Import and Export - Jan 13, 2025

cf[-https://forums.unrealengine.com/t/5-5-not-able-to-import-animation-curves-since-5-3-5-5/2267442/4-] Be carefull there is 2 bugs reported on that Forum and I think they are not related. The firs ...

A Simulating Physics component with StartAwake = false will be awoken by a Welded component

UE - Simulation - Physics - Jan 10, 2025

A Simulating Physics component with StartAwake = false will be awoken by a Welded component If a welding occurs during the call to OnCreatePhysicsState, this breaks the start awake disabled flag. Th ...

Keep Simulation Changes will persist only a subset of changed properties

UE - Editor - Jan 10, 2025

As per the steps to reproduce, Keep Simulation Changes will often only copy back the most recent property changed on a simulating Actor back to the version of the Actor in the Editor level. It is no ...

Substrate Add node only adds the first Substrate Slab's Emissive value when "Use Parameter Blending" is enabled

UE - Graphics Features - Substrate - Jan 10, 2025

As per the steps to reproduce, the Substrate Add node only adds the first Substrate Slab's Emissive value when "Use Parameter Blending" is enabled. Leaving "Use Parameter Blending" unchecked on the ...

Material Emissive Color not working with SkyAtmosphereIlluminance Material Expression

UE - Graphics Features - Jan 9, 2025

A licensee has reported that they are unable to use an emissive material utilizing the SkyAtmosphereLightIlluminance material expression together with Nanite and Lumen. The linked UDN has some more ...

Unnatural de-overlap occurs when moving inside a mesh-type collision located far from the origin

UE - Simulation - Physics - Jan 8, 2025

The problem appears to occur when the distance from an edge is mixed with positive and negative values in VectorEPA function. The following workaround is suggested that uses absolute values of dista ...

Editor FPS has significant drop when moving a BSP brush in level with multiple BSPs

UE - AI - Navigation - Jan 8, 2025

Editor performance plummets when moving BSP brushes in a level with several other BSP brushes present. Navmesh regeneration is the main cause as the full bounds for all BSP are used to determine whi ...