Unreal Engine Issues
Unreal Engine Issues
Missing UV Clamping or Clear in SunAlphaPS_Mobile
UE - Platform - Mobile - Nov 13, 2025In: void SunAlphaPS_Mobile( float2 InUVs[8] : TEXCOORD0, in FStereoPSInput StereoInput, out HALF_TYPE OutColor : SV_Target0 ) { OutColor = SunUnBias(SunShaftAndDofTexture.Sample(SunShaftAndDo ...
Incorrect config property serialization for UStructs used as TMap keys or contained in a TSet with a single value. Diffs taken from default-value of each member type, instead of from default-value of the struct
UE - CoreTech - Nov 18, 2024Consider a UStruct with some basic type members, each one with a default value specified in the struct. Also consider a TSet or TMap with that struct as keys, used inside a UObject as a UProperty an ...
Lumen tile classification flicker
UE - Rendering - Graphics Features - Lumen - Apr 19, 2023While we suggest using screenpercentage at 25%, it is visible at higher percentages. Video showing the flickering:https://udn.unrealengine.com/s/contentdocument/0694z00000Qw4jPAAR ...
Sphere Mask ArgInvHardness missing multiplication
UE - Rendering - Architecture - Materials - Jun 27, 2025Hi Epic, In MaterialExpressions.cpp UMaterialExpressionSphereMask::Compile(), hardness is not calculated the same way in both <if> conditions. One is missing a multiplication by 0.01f. Specificall ...
GAS: Duration GameplayEffects applying same GameplayCue tag will on authority end all on-going GameplayCueNotifies when first cue expires
UE - Gameplay - Gameplay Ability System - Aug 16, 2024When multiple duration GameplayEffects apply a GameplayCue with the same tag, the network authority game instance (standalone & servers) will remove all GameplayCues with that tag from the AbilitySy ...
PDI-DrawPoint - Zoomfactor being calculated incorrectly
UE - Rendering - Graphics Features - Feb 20, 2017A licensee has reported that the ZoomFactor variable inside of the DrawPoint function is being calculated incorrectly. It currently is calculated using the lesser of the projection matrix's horizont ...
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 ...
Long thin spinning objects take too long to stop spinning
UE - Simulation - Core - Jun 5, 2023See the SpinningObjectStability test map in the Physics Sandbox. [Link Removed] It's not clear if this is a bug or a side effect of some of our solver shortcuts (e.g., omission of the precession te ...
FBX animations generated under fractional framerates fail to import
UE - Anim - Runtime - Aug 24, 2022We now have the following error that is generated in FFbxImporter::ValidateAnimStackif (!FMath::IsNearlyZero(SubFrame, KINDA_SMALL_NUMBER) && !FMath::IsNearlyEqual(SubFrame, 1.0f, KINDA_SMALL_NUMBER ...
Disabling bLerpUVs in Nanite Settings of Static Mesh causes texture warping in clusters
UE - Rendering - Graphics Features - Nanite - Jan 21, 2025The licensee has identified a potential fix by changing if( Settings.bLerpUVs ) to if( Settings.bLerpUVs || UVIndex == 0 ) On line 389 of NaniteBuilder\Private\Cluster.cpp in UE 5.5 ...