Unreal Engine Issues
Unreal Engine Issues
Wrong calculation of "MaxAllocatedCountEstimate" inside FNiagaraRendererRibbons::GenerateDynamicData()
UE - Niagara - Mar 20, 2026Starting with UE 5.4, function FNiagaraRendererRibbons::GenerateDynamicData() from file [NiagaraRendererRibbons.cpp] attempts to calculate DynamicData->MaxAllocatedCountEstimate as such: DynamicDat ...
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 ...
Numerous LogMetal: Warning: AsyncCopyFromBufferToBuffer on overlapping ranges Warnings
UE - Graphics Features - Mar 13, 2018Numerous LogMetal: Warning: AsyncCopyFromBufferToBuffer on overlapping ranges Warnings Warnings do not appear to be linked to any visual/performance problems in the editor. Could be safely ignored. ...
Foliage's Landscape Layers are not reflected when Landscape is rotated
UE - LD & Modeling - Terrain - Landscape - Feb 19, 2020This problem seems to occur because Rotation is not taken into account when calculating Weight. I have confirmed that it can be solved by calculating the rotation as follows.float ULandscapeCompone ...
New Viewport Resolution setting increases every time a new PIE window is launched
UE - Editor - UI Systems - Slate - Sep 2, 2022When closing a PIE viewport, we write the size back to the New Viewport Resolution setting in case the window was resized during play. However, we do not account for the window border, and write bac ...
Roughness rendering differently on Macs
UE - Graphics Features - Oct 4, 2016The roughness value for Macs renders differently (less rough or glossy) compared to Windows. It also seems to render as expected within the Material Editor preview window, but when applied to an obj ...
FBX files with multiple Meshes with only 1 unwrap per mesh will have invalid Light Map coordinates assigned
Tools - Jun 8, 2014An FBX with Multiple Meshes and only one unwrap per mesh (no 2nd UV channel) will import the first mesh in the file correctly but will produce invalid lightmass settings on each additional mesh impo ...
Setting size of GameViewportClient gives different results on Android than in Editor
UE - Platform - Mobile - Feb 9, 2017Setting size of GameViewportClient gives different results on Android than in Editor OpenGL ES renders with the viewport origin in the bottom left, so that's potentially related to the problem. A ...
Unable to increment TMap value if Key is zero
UE - Gameplay - Feb 24, 2017Unable to increment TMap value if Key is zero. Changing the TMap Key to 1 on Add will allow the Value of "Key 0" to be incremented. User Description: It seems as if the 'Find' node for the newly ...
GetStaticRayTracingGeometries doesn't check if mesh has ray tracing disabled
UE - Rendering - Graphics Features - Ray Tracing - Nov 12, 2025An ensure is hit for static raytracing geometry because skeletal mesh assets that had ray tracing disabled were not handled in: FSkeletalMeshSceneProxy::GetStaticRayTracingGeometries The concurrent ...