Unreal Engine Issues
Unreal Engine Issues
delete_all_material_expressions_in_function Doesn't delete all expressions in one go.
UE - Rendering - Architecture - Materials - May 24, 2024UDN: https://udn.unrealengine.com/s/case/500QP000009NxNBYA0/deleteallmaterialexpressionsinfunction-doesnt-delete-all-expressions-in-one-go?fromCase=1 A UDN user is reporting that the delete_all_mat ...
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 ...
Point light missing issue on PowerVR GE8xxx when GPUScene is enabled
UE - Platform - Mobile - Systems - Sep 17, 2025On PowerVR GE8xxx devices (e.g., GE8320), running with GPUScene enabled on the OpenGL ES path, point/local Lights render nothing or significantly weak result. Withouy GPUScene(UniformView/UBO path), ...
Geometry Collections built with "Use Root Proxies" rendering/transform positions ignore the original root node rotation and can lead to unexpected behaviors
UE - Runtime - Deformable - Nov 17, 2025Geometry Collections (GC) built with "Use Root Proxies" rendering/transform positions ignore the original root node rotation and can lead to unexpected behaviors. If the root node of the GC was rot ...
Getting Vector Parameter Values from a Dynamic Material Instance with 1 or more vector parameters returns an empty array
UE - Rendering - Architecture - Materials - Jan 3, 2023This is not a regression. Tested in //UE5/Release-5.0 CL20979098 The array for Vector Parameters isn't getting populated when called from a Dynamic Material Instance. ...
ReturnUntouchedSceneColorForPostProcessing ignores view overrides and breaks splitscreen
UE - Rendering - Architecture - Sep 17, 2026When a view extension uses ReturnUntouchedSceneColorForPostProcessing and uses split screen, the final view is incorrect (clipped) because ReturnUntouchedSceneColorForPostProcessing doesn't take int ...
Open Formats: USD Reimport - settings for USD not getting stored
UE - VEI - Open File Formats - Oct 16, 2026Legacy USD importer doesn't remember import options after editor restart. Issue affects both 5.7 and 5.8. The user's choice for "Kinds to Collapse" is stored as a editor preference rather than per a ...
Lumen Reflections in Stereo are broken after Nvidia GPU Driver Update
UE - Platform - XR - Jul 29, 2024After updating the NVidia graphics driver to v.552.74+, reflective/mirror materials appear broken and render with black and white lines in VR mode if they are in a level with a Post Process Volume w ...
Does FSlateElementBatcher::AddCachedElements need to check if r.HDR.UI.CompositeMode is enabled?
UE - AI Workflows - UI Systems - Aug 28, 2024When a specific configuration of HDR cvars are set, PIE in a New Editor Window will not render the game world. Settings (For DefaultEngine.ini): ```[SystemSettings] r.AllowHDR=1 r.HDR.Display.Color ...
Crash in FMovieSceneNumericVariant::Set when loading a Level Sequence with Custom Time Warp on Android
UE - ACT Character - Sequencer - Aug 14, 2026On Android, loading a Level Sequence fatals in the async loading thread: Assertion failed: (NewValue & ~PAYLOAD_Bits) == 0 MovieSceneNumericVariant.cpp:133 Unable to store a pointer outside of a ...