Animated characters may appear in A pose after loading a file with Path Tracer enabled

TM - Rendering - Mar 12, 2025

When saving a file with Path Tracer enabled at the time of save, animated characters will appear in an A pose state. This will persist until Path Tracer is disabled. Occurs in Twinmotion 2024.1.2 a ...

Importing static mesh while a PIE session is running permanently breaks nanite on the asset

UE - Editor - Content Pipeline - Import and Export - Mar 12, 2025

Importing a Static Mesh during PIE can cause it to never enable Nanite, even if it reports that Nanite is enabled. To re-enable Nanite on the mesh, the asset needs to be deleted and imported again ...

FJsonObjectConverter::ExportCallback_WriteISO8601Dates allows for writing FDateTime that does not have ticks

UE - CoreTech - Mar 12, 2025

Context: `FJsonObjectConverter` is a built-in UE class that makes it easy to convert JSON objects to and from UStructs, including `FDateTime`, which implements a date and time. Problem: An uniniti ...

Deadlock running anim modifiers that affect bone tracks on multiple sequences

UE - Anim - Runtime - Mar 11, 2025

Running anim modifiers that affect bone tracks can deadlock the editor when applied to multiple anim sequences. ...

Shading error after flipping normals on mesh

TM - Interoperability - Mar 11, 2025

As far as I can guess is that in the initial state of the object, the vertex normals are as they come from the DCC, but after the modeling operation they get recalculated somehow that doesn't match ...

GPU crash accessing Scene_GPUScene_GPUScenePrimitiveSceneData

UE - Rendering Architecture - RHI - Mar 11, 2025

Incorrect derivative ops detection when Add node is used with Nanite Pass Switch node in material graph

UE - Graphics Features - Mar 11, 2025

Plugging an Add node which adds a constant value into a Nanite Pass switch node results in derivative ops to be detected where there should be none (which show up as red in the No Derivative Ops deb ...

Duplicating SkeletalMesh in packaged game causes crash

UE - Graphics Features - Nanite - Mar 11, 2025

This code worked until UE5.4. NaniteResource added in 5.5 causes this issue. ...

Ensure failing when compiling Macro Library blueprints

UE - Framework - Blueprint Compiler - Mar 10, 2025

When painting on a landscape with edit layers, there are UV distortions happening across the boundaries of paint layers when material is using SetMaterialAttributes

UE - Graphics Tools - Terrain - Landscape - Mar 10, 2025

Context Landscape Edit Layers enables users to paint landscapes using non-destructive layers, and can add multiple layers to the landscape that can be edited independently from each other. Problem ...