Unreal Engine Issues

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

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 ...

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

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

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 ...

Shading error after flipping normals on mesh

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

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

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

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

Ensure failing when compiling Macro Library blueprints

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

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

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 ...