Unreal Engine Issues

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

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

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 ...

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. ...

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 ...

Artifacts in imported GLB and GLTF files

Reported in SF [Link Removed] Client reports that many of their GLB and GLTF files they use appear with visual artifacts when imported to Twinmotion. These artifacts only appear in Twinmotion and n ...

Crash when moving map assets used as level instances

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

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 ...