Unreal Engine Issues

SpringArmComponent with "Use Camera Lag Substepping" does not handle fluctuating frame rates correctly

The description of SpringArmComponent's "Use Camera Lag Substepping" option says "sub-step camera damping so that it handles fluctuating frame rates well". However, as noted and explained by a licen ...

Calling SetupAttachment/AttachToComponent with 'this' as the parent inside a USceneComponent subtype's C++ ctor for nested component subobjects will result in all instances of the nested default subobject trying to attach to the CDO at registration time.

This occurs because the 'AttachParent' property is a UPROPERTY, and as a result when we create a new instance of a USceneComponent subtype, any USceneComponent subtypes it owns are treated as instan ...

Action event in the blueprint graph leads to state dirty.

BP state get dirty if the BP graph have action input event. Regression: Yes, it is not reproduced in 4.16.3 This issue is not related to Blueprint Compilation Manager. ...

GAS: RemoveReplicatedLooseGameplayTag on unadded tag causes it to be replicated

A UDN user found that calling AbilitySystemComponent->RemoveReplicatedLooseGameplayTag(TagToRemove); while the gameplay tag was not in the TagMap, will create an entry for it with count 0, see ...

FMediaFoundationMovieStreamer::Init() returns true even if the movie could not open.

UWorld::GetNetMode returns incorrect value during UGameInstance::StartPlayInEditorGameInstance

During PIE instance initialization, there seems to be a window during which UWorld::GetNetMode will not return the expected value: before the instance's NetDriver has been created but after UGameIns ...

GPU Particle Collision causes shaking when set to bounce with low resilience.

A particle emitter with GPU sprites on certain settings will shake violently as they collide with the ground. This requires there to be a strong Const Acceleration module and Collision with low resi ...

LIVE: Code projects using TextureRenderTarget2D will not build because UTextureRenderTarget is undefined in TextureRenderTarget2D

If a TextureRenderTarget2D is used in a code class, the build of the project will fail with an error stating that the UTextureRenderTarget base class is undefined. The line #include "Engine/TextureR ...

Toggling a Spline component from an open/closed loop through bp's isn't reflected

Toggling a Spline component from an open/closed loop through bp's isn't reflected ...

BP class variables aren't created for component templates not loaded in an uncooked server build due to component class NeedsLoadForServer() API override.

See UDN thread for details. Essentially we need to ensure that class variables are created for SCS components even if the template isn't loaded as a result of a NeedsLoadForServer() API override. O ...