Unreal Engine Issues
Unreal Engine Issues
Artifacts appear on translucent particle systems during camera motion blur
UE - Rendering Architecture - Jul 23, 2025Translucent particle systems exhibit visual artifacts when the camera moves, even though motion vectors are disabled for the particle emitters. While switching the Translucency Pass to "After Motio ...
Custom Primitive Data color widget not applying correctly to static mesh components in Blueprint editor.
UE - Rendering Architecture - Materials - Jul 23, 2025Context Custom Primitive Data is used to store custom data in an index array that is accessible through Blueprint and code. This allows for variations across instances of the same mesh without needi ...
The speed and delay of Animators is increased in exports when the scene contains 3D Grass
TM - Rendering - Jul 23, 2025Reported in SF [Link Removed] For animators (translators and rotators), when the scene contains the 3D Grass materials, videos exported from the scene will display animators delay and speed up abou ...
Farfield shadow in lumen scene
UE - Graphics Features - Jul 21, 2025Shadows in the Lumen Scene from Lumen's Direct Lighting do not match the world when in the Lumen Far Field. This leads to shadows where there should not be any, and missing shadows where there shou ...
Montage Editor: Mouse Wheel Cannot Scroll to the Bottom of notify section when there are many track.
UE - Anim - Runtime - Jul 21, 2025When a large number of notify tracks are added in the Montage Editor, the mouse wheel scroll does not allow the user to reach the bottom-most tracks. Only by manually dragging the scrollbar can the ...
Unable to change Actor Coloration View Modes in PIE
UE - World Creation - Worldbuilding Tools - Jul 20, 2025When in PIE changing Actor Coloration view modes from the viewport visualisation mode [Liit] -> [Actor Coloration] -> ... Does not update correctly when switching view mode and sometimes isn't corr ...
Soft angular constraints solve velocity like hard constraints
UE - Simulation - Physics - Jul 17, 2025Soft angular constraints are solving velocity like hard constraints. Instead of swinging back and forth, the affected body just snaps to 45 degrees. Check the steps to reproduce for more details. Th ...
Structured log automated decimal number tests fail in languages / cultures that use commas instead of periods
UE - Foundation - Jul 17, 2025The following Localisation Tests in "Engine\Source\Runtime\Core\Tests\Logging\StructuredLogFormatTest.cpp:275" TestLoc(LOCTEXT("Float", " {Float} "), ANSITEXTVIEW(R"(128.25)")); TestLoc(LOCTEXT ...
Performance slowdown when ray tracing is disabled due to SetResidencyPriority
UE - Rendering Architecture - RHI - Jul 17, 2025When a game is compiled with ray tracing disabled (D3D12_RHI_RAYTRACING=0) and the GPU the game is running on becomes low on VRAM, frame time is negatively impacted and doesn't recover. The D3D12_RH ...
Niagara Regression - Looping particle with Spawn Burst Instantaneous on time 0.0 flickers for a frame between loops
UE - Niagara - Jul 16, 2025Note: This worked correctly up to UE 5.4, but repros from UE 5.5 up to mainline latest. If a Niagara Emitter is set up with "Spawn Burst Instantaneous" on time 0.0, and the spawned particle(s) have ...