Unreal Engine Issues
Unreal Engine Issues
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 ...
When moving actors to the current level, their label is reset and displayed incorrectly on the Scene Outliner until the next time it is refreshed
UE - Editor - Workflow Systems - Jul 14, 2025This is a regression, it worked correctly up to UE 5.4, but repros on UE 5.5 and 5.6. Also, this seems related to [Link Removed], which was fixed by CL 40649716/40649749 and integrated into UE 5.6, ...
Channel Mask Parameter does not correctly pull through the Alpha channel from
UE - Rendering Architecture - Materials - Jul 8, 2025The ChannelMaskParameter node in the Material Graph works in most cases, but unusually does not work when extracting the value of the Alpha channel only for Vertex Color input data. ...
Assigning a static mesh to a Mutable Clip Mesh With Mesh Node can crash the editor
UE - Anim - Mutable - Jul 4, 2025Context: The Mutable plugin has a modifier node called Clip Mesh With Mesh that allows Static Mesh modifiers to be assigned as the clip mesh. Under certain circumstances, an assert can be triggered ...
Sequencer - When a subsection has negative play rate, any nested sub-subsections fail to evaluate
UE - Anim - Sequencer - Jul 3, 2025Consider a sequence hierarchy with more than two layers. If the top-level sequence uses a negative timescale on a sub-sequence, the contents inside it animate as expected, but any nested sub-sequenc ...
In a Geometry Collection, enabling Nanite Fallback in a Nanite Enabled collection won't generate a Physics Body when Nanite is disabled
UE - Simulation - Physics - Destruction - Jun 30, 2025In a Geometry Collection, enabling Nanite Fallback in a Nanite Enabled collection won't generate a Physics Body when Nanite is disabled. To verify this, follow the steps provided in the Steps to Re ...
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 ...
Water Body Custom generates Map Check Warnings
UE - Graphics Tools - Terrain - Water - Jun 26, 2025From licensee: Water Body Custom Actors generate this warning during Map Check: WaterBodyCustom_UAID_507C6F36B9215C5B02_1871778061 Static mesh actor has NULL StaticMesh property. To reproduce, si ...
TInstancedStruct used in native actor class loses reference to Instanced UObject after BP recompilation
UE - Foundation - Jun 25, 2025When a TInstancedStruct contains a UObject marked with EditInlineNew and DefaultToInstanced, the reference is lost after compiling the Blueprint but only when the struct is part of a native Actor cl ...
Enabling bUpdateComponentTransformToRootBone in a GeometryCollectionComponent causes broken particles to appear in the wrong location
UE - Simulation - Physics - Destruction - Jun 22, 2025Enabling bUpdateComponentTransformToRootBone in a GeometryCollectionComponent causes broken particles to appear in the wrong location. When that flag is true, the moment the GeometryCollection (GC) ...