HZB Occlusion causes large stalls on the render thread

UE - Rendering Architecture - RHI - Oct 7, 2025

HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...

TMap "Categories" meta propagates into structs it shouldn't apply to

UE - Gameplay - Gameplay Tags - Sep 22, 2025

When using TMap with "Categories" meta UPROPERTY tag for gameplay tags, it propagates into structs that it shouldn't reaching into. The expectation is that it would only impact the layer of gameplay ...

LODs with screen size 0 in legacy assets are incorrectly converted to 1 on load

UE - Editor - Content Pipeline - Sep 11, 2025

When loading a mesh asset (static or skeletal) created in an old version of Unreal (e.g. 4.10), any LOD whose LOD screen size was originally set to 0, is converted to 1. This causes LODs that would ...

StopMontage with different BlendOutTime not taken into account after first StopMontage

UE - Anim - Gameplay - Nov 19, 2024

When an animation is currently blending out due to automatic blend out or GameplayLogic, further StopMontage with specific BlendOut will not update the time to blend out of the current blending out ...

[StateTree] Reentering current state immediately after exiting does not reset variables on tasks with "Should State Change on Reselect"

UE - AI - StateTree - Nov 7, 2024

Context State Tree Tasks have a configurable default value 'Should State Change on Reselect' which controls whether the task receives a EnterState/ExitState if completion of the current state is fo ...

AppleARKit forces view projection matrix according to device viewport

UE - Platform - XR - Nov 5, 2024

[Link Removed] ...

The tooltip of a UPROPERTY enum is not refreshing in UDetailsView

UE - Editor - UI Systems - Oct 15, 2024

There is an issue with UPROPERTY enums where the tooltip does not update as expected. When the DetailViewWidget is refreshed, the tooltips appear correctly. For example, ToggleShowingOnlyAllowedPro ...

Lumen doesn't use correct sky light settings when GI scalability changes from Low to High

UE - Graphics Features - Lumen - Sep 24, 2024

When the Global Illumination scalability settings are changed in the editor from High to Medium, they primarily act on the r.Lumen.DiffuseIndirect.Allow and r.SkyLight.RealTimeReflectionCapture.  No ...

Runtime Virtual Texture (RVT) baked mips using Streaming Virtual Texture (SVT) only bakes the base colour

UE - Graphics Features - Sep 13, 2024

Using Streaming Virtual Textures for the lower mips of an RVT using Base Color, Roughness, Normal seemingly leads to both roughness and normal being sampled as 0. This causes a significant shading a ...

Affect Indirect Lighting While Hidden can affect the environment after data layer unload in editor

UE - Graphics Features - Sep 9, 2024

After setting Affects Indirect Lighting While Hidden but before saving the level, the emissive contribution persistents through datalayer visibility toggles. This does not appear to occur in PIE, on ...