Unreal Engine Issues
Unreal Engine Issues
Implied Decal Blend Modes don't properly account for Material Attributes usage
UE - Rendering - Architecture - Sep 28, 2021I've attached a project with the necessary materials that demonstrate this issue. I would expect that just because a Set Material Attributes node is inside a material graph it wouldn't affect the de ...
Having a block in layout before switching to overlay strategy affects the overlay output.
UE - Anim - Mutable - Mar 5, 2026Issue: If "Resizable" Layout Strategy contains a block, it will influence the "Overlay" Layout Strategy. Expected behavior: When using "Overlay" Layout Strategy, it should disregard whatever the "R ...
Nanite Landscape Visibility Layer Crash
UE - Graphics Tools - Terrain - Landscape - Jun 10, 2026Upon saving the level after creating the landscape and painting visibility, the editor crashes. When you restart the editor and load the level, you are greeted with a warning in the upper right corn ...
VisualizeTexture with the BMP flag causes a crash when any mip over mip0 is requested
UE - Rendering - Architecture - Dec 18, 2024When a mip level higher than 0 is requested in VisualizeTexture, the engine will crash. The root cause appears to be VisualizeTexture.cpp:924, on which an incorrect mip level is used to read a non-m ...
[CrashReport][Crash] Engine!FSceneViewport::UpdateViewportRHI() [SceneViewport.cpp]
UE - Rendering - Architecture - RHI - May 29, 2026#200 crash out of 2101 in UE 5.8 on Windows#34 crash for UE - Rendering - Architecture in UE 5.8 on Windows#20 crash for UE - Rendering - Architecture - RHI in UE 5.8 on WindowsAssertion failed: IsI ...
UnkownRef Mips can cause TextureStreaming peaks during loading
UE - Rendering - Graphics Features - Mar 27, 2023UnkownRef Mips is meant to fix/workaround the problem where some textures are used for rendering but they don't have any component references them (such as texture used by PP effects) These UnkownR ...
Lumen Card Sharing is active on material with custom primitive data
UE - Rendering - Graphics Features - Lumen - Aug 13, 2025The wrong emissive value may be used on Nanite objects with custom primitive data when Lumen card sharing is enabled. This issue can be mitigated with: r.LumenScene.SurfaceCache.AllowCardSharing 0 ...
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 ...