Blend Stack node doesn't have a valid FDeltaTimeRecord

UE - Anim - Runtime - Apr 19, 2024

The blend stack node doesn't generate any values for its DeltaTimeRecord.  This can be tested with the fix for [Link Removed] shelved at 32747789.  Since there isn't a tick record directly associate ...

Add Substrate Material Support to Lumen Performance Overview

UE - Graphics Features - Substrate - Feb 10, 2025

There is a discrepancy when inspecting Substrate materials in the Lumen Performance Overview. Compared to viewing non-Substrate materials the overview show all surfaces in red indicating that Lumen ...

Disabled Skeletal Mesh Sections cause Shadow Ray Tracing Flicker

UE - Graphics Features - Ray Tracing - Dec 12, 2025

If a skeletal mesh has a section disabled the ray traced shadow will flicker when the camera or itself moves. Previously in 5.6.0 no raytraced shadow would appear if a section was disabled. This wa ...

Cannot move instances of a hierarchical static mesh component in the blueprint editor viewport

UE - Gameplay - Components - Apr 12, 2016

Can move individual mesh instances of a regular instanced mesh component in the blueprint editor, but not hierarchical ones. Originally reported as a pull request in [Link Removed], but we rejected ...

Landscape components render black

UE - LD & Modeling - Terrain - Landscape - Dec 1, 2016

Workaround:Open the Landscape Material and click SaveReload the level Landscape components render black upon first-time compile. Observed in QA-Landscape - several chunks of the Landscape were bla ...

Ensure fires during nativized build while packaging for any BP class based on UAnimNotify

OLD - Anim - Oct 25, 2018

Cooking will fail while attempting to convert a non-data-only Blueprint class based on the native UAnimNotify class when Blueprint nativization is enabled. Workaround in lieu of a fix would be to e ...

Certain combinations of 'bRenderStatic' and 'bNoSkeletonUpdate' on SkeletalMeshComponent produce undesirable behavior.

UE - Graphics Features - Aug 7, 2019

Issues observed:  - When bRenderStatic is on and bNoSkeletonUpdate is off, CachedMeshDrawCommands takes a significant chunk of time, because the scene primitive transform is being updated every fra ...

Landscape Tessellation Issues

UE - LD & Modeling - Terrain - Landscape - Sep 23, 2019

We are having a display issue with tiled landscapes displaying well below full tessellation in editor, but displaying fine in game. We can "fix" this issu by unchecking "Use Default Falloff" in deta ...

SetCollisionEnabled shouldn't check owner

UE - Simulation - Physics - Nov 8, 2019

Attempting to set the collision of a component to NoCollision while the actor's collision is disabled will prevent the component's collision from changing. This is because of the early exit in UPrim ...

Physics Constraint Actor Won't Disable Collision Between Two Actors That Are Already Colliding

UE - Simulation - Physics - Feb 17, 2020

Meshes that are colliding that are set as constraint actors don't follow the Physics Constraint Actors "Disable Collision" parameter if they are colliding prior to being set as constrained actors. ...