When a Niagara User Parameter is renamed, mesh bindings on Niagara Mesh Renderers are not updated, and the binding is silently broken

UE - Niagara - Mar 13, 2025

In Niagara, Mesh Renderers expose a "Meshes" array for selecting the meshes to be rendered. On each array entry, a property "Mesh Parameter Binding" is available and allows the user to override that ...

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 ...

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. ...

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 ...

Popping Ribbon UVs

UE - Niagara - Mar 10, 2025

Please see the Additional Link for related UDN information. The UV popping described can be subtle, depending on settings; it's affected by spawn rate and GPU vs CPU. The popping shown in the gif t ...

Crash when moving map assets used as level instances

UE - World Creation - Worldbuilding Tools - Level Instances - Mar 10, 2025

AssetRegistry has poor performance when a large map is resaved: Directory IO

UE - Foundation - Data Pipeline - Cooker - Mar 10, 2025

IO cost of directory scans is one of the costs present in the AssetRegistry when a large map is resaved. Maps can have external actors which all have to be rescanned and reported to the map for incl ...

Resetting material instance parameters to default value does not update the appearance of the object that the material is applied to

UE - Rendering Architecture - Materials - Mar 10, 2025

When a material instance with exposed parameters is applied to a landscape; the parameters set to a new value and then reset to back the default value, the landscape does not respect the new default ...