HZB Occlusion causes large stalls on the render thread

UE - Rendering Architecture - RHI - Oct 7, 2025

HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...

Vertex color does not work on Skeletal Mesh with Nanite enabled

UE - Graphics Features - Nanite - Oct 7, 2025

Nanite enabled skeletal meshes don't work with materials containing a vertex color node. The vertex color material does work for non-Nanite skeletal meshes and Nanite-enabled static meshes. ...

Converting a mesh to Nanite merges mesh sections with the same material index, but with different material overrides

UE - Anim - Mutable - Oct 6, 2025

When a mesh with multiple sections which point to the same MaterialIndex but have different settings enabled (e.g. bCastShadow is enabled on only one section) is converted to Nanite, the material sl ...

Recompiling an ABP that another ABP has a Property Access dependency on without recompiling/linking the other causes a crash

UE - Anim - Runtime - Anim Blueprints - Oct 2, 2025

The crash comes from the pointers in FAnimSubsystem_PropertyAccess::Library::Indirections in the layer ABP from pointing to old/invalid functions and properties from the trash ABP_Manny, as they hav ...

Update LookupProxy chooser evaluation to work with soft object references.

UE - Anim - Gameplay - Oct 1, 2025

Soft object references in proxy tables, when evaluated return a nullptr, instead of the soft object reference to load. ...

BoxOverlapActors fails to catch an Overlaped actor with a particular scale, from a particular position

UE - Simulation - Core - Sep 30, 2025

BoxOverlapActors fails to overlap a scaled Floor actor with a particular scale, from a particular position and extent. The setup is really specific and described in Steps to Reproduce. The required ...

Loading error for editor only BlueprintNativeEvent functions

UE - Framework - Blueprint Compiler - Sep 26, 2025

The editor-only function in the native parent class is not compiled in the game module, which is why we're getting this error. The Blueprint compiler should follow suit during cooking and not genera ...

Custom Depth range is different than Pixel Depth range

UE - Rendering Architecture - Shaders - Sep 25, 2025

Shaders that compare custom depth and pixel depth get wrong output values because the ranges are different. This error is most noticeable over large distances. The difference in ranges is due to t ...