Unreal Engine Issues

FILTER_COMMANDLINE_LOGGING cannot be used without forcing UE_COMMAND_LINE_USES_ALLOW_LIST

There's two ways to affect the commandline in CommandLine.cpp: FILTER_COMMANDLINE_LOGGING - for filtering certain or all args (if left empty) from the log. UE_COMMAND_LINE_USES_ALLOW_LIST - for on ...

HideBoneByName translates bone to parent which breaks skinning

Calling 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 ...

Memory leak when Lumen is disabled but r.MeshCardRepresentation=1

When Lumen is disabled, but the cvar "r.MeshCardRepresentation" is set to 1, Lumen will continuously enqueue object removal from the Lumen Scene, without ever emptying the array of primitives to rem ...

Cook Determinism - Construction Scripts and ChildActorComponent issues with DiffCooks

To step through the issue, in the -DiffOnly cook add a breakpoint to UChildActorComponent::OnRegister and UChildActorComponent::OnUnregister. It should hit 4 times:Once when LoadPackage loads the ma ...

Crash after generating HLODs for merged meshes that have all triangles culled

In UE 5.4, some config variables are not getting saved correctly, due to the new User/Editor rules.

A lot of properties are not getting saved correctly to custom configuration files. This looks like that it can be cause by the FConfigContext::PerformLoad function. New conditionals have been added ...

Nested PackedLevelActor bounds issue

Reflection Captures permanently unload with world streaming

When a reflection capture is unloaded due to streaming, it cannot be reloaded when the player returns to that area in the world because FReflectionCaptureData::OnDataUploadedToGPUFinal deletes the C ...

UHapticFeedbackEffect_SoundWave Initialize does not populate Raw Data in the HapticsBuffer

From the UDN:  >  Open HapticsFeedbackEffect.cpp and naivgate ~ line 150; note HapticBuffer has length populated but never write the actual buffer data. LikeReplySelect as Best Seems like a simple f ...

GPU ISM LOD uses bounds length instead of radius

When calculating LOD for instances on GPU in NaniteCullingCommon.ush we use:float RadiusSq = length2(LocalBoxExtent); This doesn't exactly match the CPU logic for static mesh component LOD select ...