IsTraceHandleValid with default FTraceHandles has unexpected behavior on the first frame

UE - Simulation - Physics - Sep 18, 2018

Because both FWorldAsyncTraceState's CurrentFrame and FTraceHandle are default initialized to 0, on the first frame, if a new Asnc Trace starts all default FTraceHandles will reference the same (now ...

Using a Blutility to modify an Actor in a Streaming Level doesn't make it dirty

UE - Gameplay - Oct 11, 2018

Using a Blutility to modify an Actor in a Streaming Level doesn't make it dirty and prompt it to be saved. This was reproduced and tested in 4.19.2 (CL-4033788), 4.20.3 (CL-4369336), 4.21 (CL-44358 ...

UWorld::CleanupWorld causes issues with sublevels when changing maps after building lighting

Tools - Mar 1, 2019

A licensee has reported that UWorld::CleanupWorld is causing issues with assets in Sublevels if you build lighting on the parent level, save all of the maps, and then change to another level. The as ...

Sequential Level Loading in Python causes Crash

UE - Editor - Workflow Systems - Apr 16, 2019

Loading all the levels selected in the Content Browser and running the aforementioned Python script causes the editor to crash Tested in 4.20.3 (CL - 4369336), 4.21.2 (CL - 4753647), 4.22 (CL - 5 ...

Virtual Texturing causes crash

UE - Graphics Features - Jul 29, 2019

Virtual streaming a 4K texture and setting the max texture size to 2048 causes the engine to crash. Tested in 4.21.2 (CL - 4753547), 4.22.3 (CL - 7053647), 4.23 (CL - 7445012), 4.24(CL - 7646041) ...

Set Component Tick doesn't work on Cascade Particle Systems

UE - Niagara - Jul 31, 2019

Changing the Component Tick Interval via Blueprints has no effect on Cascade particle system components. Tested in 4.21.2 (CL - 4753647), 4.22.3 (CL - 7053647), 4.23 P3 (CL - 7445012), 4.24 (CL - ...

Landscape surface type always return "Default"

UE - Simulation - Physics - Dec 26, 2019

The behavior in this bug is a little odd since it is not present in any project that is upgraded to 4.24.1 (CL-10757647), but only those that are created directly in 4.24.1. The behavior is also a l ...

Textures become darker on BSPs when converted to a Static Mesh using Baked Lighting

UE - LD & Modeling - Modeling Tools - BSP - Jan 16, 2020

A BSP converted to a Static mesh shows a much darker texture material when built with Static/Baked lighting. This was reported and tested in 4.24.1 (CL-10757647). This was reproduced in 4.23.1 (CL ...

Sorting a Blueprint variable into a subcategory separates variables into separate category structures

UE - Gameplay - Blueprint - Oct 14, 2019

Within the Blueprint Editor, it is possible to create subcategories for variables to be sorted into. Doing so separates variables not nested into subcategories out into standalone, top-level structu ...

RGB/UINT10 HDR Format not using ST.2084

UE - Rendering Architecture - RHI - Aug 23, 2021

Specification here: [Link Removed] Which is mirrored in engine in FD3D12DynamicRHI::Init (for example): [Image Removed] However, FWindowsPlatformMisc::ChooseHDRDeviceAndColorGamut always returns ...