Unreal Engine Issues

Screen Probes and Specular Firefly Flickering near screen edges

Lumen's rough specular indirect lighting buffer can have fireflies along the bottom and right edges of the screen. Also tested in //UE5/Main, CL: 35177423 ...

Using Fracture/Chaos Destruction with TSR as Anti-Aliasing Method generates smeared images.

Using Fracture/Chaos Destruction with TSR as Anti-Aliasing Method generates smeared images whenever the debris are moving. The client pointed out that the issue might come from GeometryCollectionCom ...

Ambient Occlusion darkens the entire scene in VR Preview

A sampling result of DistanceFieldAOHistory is shifted to a wrong position.

DistanceFieldAOHistory introduces ghosting at low scalability and low screen percentages. This can lead to AO artifacts and a ghosting effect from the character. This issue was also observed on //U ...

Modifying FSuggestProjectileVelocityParameters::ResponseParam.CollisionResponse modifies FCollisionResponseParams::DefaultResponseParam

FSuggestProjectileVelocityParameters was introduced in 5.4 and has a FCollisionResponseParams member that's initialized as a mutable reference to FCollisionResponseParams::DefaultResponseParam. str ...

BakedSourceTexture missing from Sprite in packaged game

The UPaperSprite::BakedSourceTexture will be nullptr in a packaged game if the sprite is not referenced by the UGameInstance.  The attached sample project demonstrates this scenario. ...

Play options menu vanishes sometimes

There seems to be something wrong with how we close menus and submenus as submenus are opened and closed based on mouse interaction. In particular, we seem to sometimes close the whole menu hierarch ...

World is initialized twice when opened through the Content Browser

When opening a Level from the Content Browser, the world gets initialized twice. This initialization process can be quite long, especially for big world using world partition. There doesn't seem to ...

HZB Occlusion causes large stalls on the render thread

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 ...

Subobject of garbage actor may be reassigned to newly created actor on the client

When an actor channel is cleaned up, the actor and its subobjects in the CreateSubObjects array are destroyed/marked as garbage in DestroyActorAndComponents. However, default subobjects are not adde ...