Pre-UE5 serialized FVariant FVector data corruption when deserialized in UE5

UE - Gameplay - LWC - Jan 15, 2024

FVariant is a struct that implements a union of data types, including FVector. When assigning an FVariant an FVector value in engine versions UE 4.27 or earlier, the FVariant will deserialize incorr ...

Applied external forces to vehicles may be nullified by sleeping

UE - Simulation - Physics - Solver - Jan 12, 2024

If Entering sleeping state and applying external force are same time, the external force is nullified and the vehicle stops immediately. p.Chaos.Solver.SleepEnabled 0 or __ setting SleepLinearVel ...

Double clicking on Interface Function in Blueprint Graph does not take you to the function implementation.

UE - Editor - Jan 11, 2024

When double-clicking on an interface function call within a blueprint, the expected behaviour is that it will take you to the implementation of this function. However, it currently does nothing. ...

Specular/Anisotropy problems with Nanite Meshes

UE - Rendering Architecture - Jan 11, 2024

Specular highlights can disappear with clearcoat materials, when "Clear Coat Enable Second Normal" is enabled ("r.ClearCoatNormal"). ...

UObject Macro Libraries cannot use functions that require a WorldContext

UE - Gameplay - Blueprint Editor - Jan 11, 2024

If you make a Blueprint Macro Library that derives from UObject you are then unable to use any functions that require a WorldContext, like Delay. This is because the WorldContext cannot be assumed l ...

Detect OnHovered event in child widgets even if HitTest(Self/Child) is disabled in RetainerBox

UE - Editor - UI Systems - UMG - Jan 11, 2024

When HitTest(Self/Child) is disabled in RetainerBox, the child widget is assumed to not fire all hit test events. However, in this case, the hit test event is fired in the child widget. This is an i ...

Capturing backtrace of another thread in engine built with clang raises access violation exception

UE - Foundation - Core - Jan 11, 2024

Engine built with Clang throws an exception when calling RtlVirtualUnwind with a different thread ID. Engines built with Microsoft compilers do not occur this problem. For example, if starting PI ...

Some debug modes do not work in PIE

UE - Platform - Mobile - Jan 9, 2024

It looks like the output of the debug pass is ignored, and the final output from the last frame before the pass was enabled is displayed instead. If the pass is modified to return a different textu ...