Unreal Engine Issues
Unreal Engine Issues
Translucent meshes randomly flicker when using VSM
UE - Rendering - Graphics Features - Jun 23, 2026Flickering can occur on translucent materials, usually in the distance when there is at least one directional light and when using VSM. Flickering seems highly dependent on framerate and timing. L ...
Non-Nanite meshes not being correctly cleared from all levels of VSMs on actor destruction when r.Shadow.Virtual.NonNanite.IncludeInCoarsePages=0
UE - Rendering - Graphics Features - Shadows - Jun 15, 2026When using the r.Shadow.Virtual.NonNanite.IncludeInCoarsePages=0 to optimize VSM performance there are errors in how the VSM is invalidated when actors are destroyed with non-Nanite meshes. The curr ...
Crash when applying Decal material with Distance Cull Fade node to Decal Actor
UE - Rendering - Architecture - Materials - Jun 15, 2026The Editor crashes when applying a Material with a Distance Cull Fade node to a Decal Actor. Fatal error: [Link Removed] [Line: 730] Missing uniform buffer at slot 2, stage SF_Pixel. Please check ...
check(bRenderStateCreated) fires in SendRenderDynamicData_Concurrent called from FRegisterComponentContext::Process
UE - Rendering - Architecture - RHI - May 18, 2026FRegisterComponentContext::Process() in ActorComponent.cpp iterates over SendRenderDynamicDataPrimitives and calls SendRenderDynamicData_Concurrent() on each. The existing guard checks ::IsValid(Pri ...
Wrong WPO motion vectors due to Periodic World Space node
UE - Rendering - Graphics Features - May 13, 2026We've noticed smearing in grass due to wrong motion vectors. This appears to be caused by lack of previous frame support in the periodic world space node. This is how we fixed it: In MaterialTempl ...
Chaos FieldSystem examples in the engine content add field nodes every Tick, which creates too many components
UE - Simulation - Gameplay - May 5, 2026Can we add the field on construction instead of on Tick to avoid the performance overhead caused by creating too many components? ...
Curve Atlas Row Parameter uses derivative ops when Texture Sample connected to curveTime input
UE - Rendering - Architecture - Materials - May 1, 2026When a Curve Atlas Row Parameter node is used with a Texture Sampler connected to the curve time input, the sample type uses derivative ops. This has negative performance implications for Nanite co ...
Blueprints: ComponentClass override causes crash on loading maps with instances saved with base class
UE - Framework - Blueprint - May 1, 2026Context In actor blueprints, you can change an inherited component’s class in the editor by selecting it in a child blueprint and changing its Component Class in the Details panel. Problem When o ...
CharacterMovementComponent boosted upward when falling into acute-angle sloped corner
UE - Gameplay - Player Movement - Apr 14, 2026In UCharacterMovementComponent::TwoWallAdjust, characters can gain unintended upward velocity (slope boosting) when hitting corners with an acute angle (<=90 degrees) while in the Falling movement m ...
Raytraced Hair Lighting using Light Functions atlas and positions the Light function material doesn't render correctly
UE - Rendering - Graphics Features - Apr 9, 2026Light functions don’t render on grooms when using ray traced shadows and positions in the light function material. The setup:A light (point/rect/spot) pointing to a groom hair system. The light's ...