Unreal Engine Issues
Unreal Engine Issues
HideBoneByName translates bone to parent which breaks skinning
UE - Anim - Jul 30, 2024Calling HideBoneByName on a bone causes that bone (and all it's children) to be translated to the parent bone's location. This code in UpdateRefToLocalMatricesInner is responsible: bool bNeedToHid ...
Landscape has a seam when scale is set to a decimal
UE - Graphics Tools - Terrain - Landscape - Jan 13, 2023Regression: Tested in UE5/Release-5.0 at CL 20979098, this issue does occur so it is not a regression. This issue occurs if the scale set for the landscape has a decimal value that is not 0.5. Sett ...
FViewElementPDI::DrawLine calls for SDPG_World are not rendered in PIE or in Game
UE - Rendering - Architecture - RHI - Jan 7, 2026When View.Family->EngineShowFlags.CompositeEditorPrimitives is false in the function RenderEditorPrimitivesForDPG. This code picks which version of the batched lines to renderconst FBatchedElements ...
Custom expression additional outputs don't work when connected to World Position Offset
UE - Rendering - Architecture - Materials - Jun 24, 2026Custom expression additional outputs are considered (0,0,0) when connected to WPO. ...
LiDAR not importing colors correctly for .E57 Point Clouds
UE - Editor - Content Pipeline - Jan 6, 2023Reproduced 3/3 times, issue does not occur in //UE5/Release-5.0 - CL 20979098 Binary. Confirmed Regression. LiDAR plugin is version .08 in UE5.0.3, and version 1.0 in UE5.1.0 ...
Open Formats: Reimport PIE - Reimporting an asset during PIE overwrites the bAllowCPUAccess value to true
UE - Editor - Content Pipeline - Import and Export - May 22, 2025When reimporting a static mesh asset before PIE execution, the value of bAllowCPUAccess is false. If reimporting a static mesh asset while PIE is running, the value of bAllowCPUAccess is true. In a ...
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 - Core - Systems - 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 ...