Unreal Engine Issues
Unreal Engine Issues
Unfocused Standalone window has reduced performance
UE - Rendering - Architecture - RHI - Aug 25, 2020User description: When I run two windowed standalone instances to test multiplayer, the unfocused window gets about 2-5 fps...but if I focus on it, smooth 120fps, yet the opposite screen is now onl ...
Crash when spawning actor with no viewport initialized
UE - Editor - Nov 22, 2023If an attempt to spawn an actor is made before the Level Editor Viewport is fully initialized (i.e. before it has had a chance to get rendered at least once), and that actor has no specific Factory ...
Crash when a subsystem calls GetSubsystemArray() on its owner while engine code is iterating on subsystems also obtained through GetSubsystemArray()
UE - Gameplay - Aug 6, 2024In some occasions, engine code iterates over a certain subsystem type by calling FSubsystemCollection::GetSubsystemArray() and then calling some method on all subsystems of the returned array. This ...
"FVector contains NaN" on packaged builds for Debug configuration
UE - Graphics Features - Lumen - May 6, 2022Customer Provided Description:This was experienced in UE 5.01 - custom installed engine (No changes to UE code, simply added the Debug build configuration, see the following command): "c:%ue_dire ...
TeleportTo result with Chaos is different from PhysX
UE - Runtime - Simulation - Jun 25, 2021The result with Chaos is not wrong, rather it returns a correct correction vector, that vector is perfectly horizontal to the teleport buried against the landscape mesh. Therefore, teleportation wil ...
Expose light depth and position to Light Functions
UE - Graphics Features - Oct 14, 2019Users have requested that light depth and light position are made available to Light Function Materials.Light Depth We seem to be calculating the per-pixel distance from the light to the surface in ...
Gauntlet test warnings in QAGame Win64 Development BootTest
UE - Rendering - Architecture - RHI - Sep 6, 2023QAGame Win64 Development BootTest: * Ensure: Ensure condition failed: oldValue == newValue [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Private\HAL\ThreadingBase.cpp] [Line: 311] oldVal ...
LevelStreamingPersistence: BP added components don't persist properties in PIE until map actor resave
UE - World Creation - Worldbuilding Tools - Mar 6, 2026Context The LevelStreamingPersistence plugin can be used to remember and restore properties on actors, components and other objects that are part of a streamed level. Persisted properties are resto ...
Prevent unnecessary rebuilds of windows resource files
UE - Foundation - Cpp Tools - UnrealBuildTool - Sep 20, 2023How Necessary are BUILT_FROM_CHANGELIST and BUILD_VERSION in Resource Files? We've been investigating ways to improve the speed of our iterative engine builds, and have found that the vast, vast maj ...
Regarding TObjectPtr performance regression
UE - CoreTech - UObject - Jul 13, 2026This is from the linked EPS case: ============================== When 5.0 first introduced TObjectPtr, the guidance was that it would compile down to raw pointer access in Shipping builds to ensu ...