Sequencer - When a subsection has negative play rate, any nested sub-subsections fail to evaluate

UE - Anim - Sequencer - Jul 3, 2025

Consider a sequence hierarchy with more than two layers. If the top-level sequence uses a negative timescale on a sub-sequence, the contents inside it animate as expected, but any nested sub-sequenc ...

Sphere Mask ArgInvHardness missing multiplication

UE - Rendering Architecture - Materials - Jun 27, 2025

Hi Epic, In MaterialExpressions.cpp UMaterialExpressionSphereMask::Compile(), hardness is not calculated the same way in both <if> conditions. One is missing a multiplication by 0.01f. Specificall ...

[AI] Spatially loaded objects in a WP map that are unloaded do not contribute to the navmesh when Build Paths is run

UE - AI - Navigation - Jun 23, 2025

Using Build Paths does not create a navmesh that also includes any Actors or Objects that are unloaded and spatially loaded. The navigation system appears to load the world within the navigable boun ...

Eye Adaptation Inverse node does not work with volumetric materials

UE - Graphics Features - Jun 23, 2025

The EyeAdaptionInverse node works differently for surface materials and volumetric materials. In surface materials, it allows to have a consistent glow during day and night time, however in a volume ...

Enabling bUpdateComponentTransformToRootBone in a GeometryCollectionComponent causes broken particles to appear in the wrong location

UE - Simulation - Visual - Jun 22, 2025

Enabling bUpdateComponentTransformToRootBone in a GeometryCollectionComponent causes broken particles to appear in the wrong location. When that flag is true, the moment the GeometryCollection (GC) ...

Instanced Static Meshes ignore max World Position Offset Displacement for bounds after UpdateInstanceTransform is called

UE - Graphics Features - Jun 18, 2025

When an Instanced Static Mesh Component (ISMC) uses a material with a non-zero Max World Position Offset Displacement, the bounds are correctly expanded at initialization. However, after calling Upd ...

In editor, sub level instance's streaming state persists incorrectly after toggling Level Behavior without saving

UE - World Creation - Worldbuilding Tools - Level Instances - Jun 11, 2025

When adding a sub level with world partition streaming to a main level where the streaming is also enabled, setting* Level Behavior* of the sub level to Standalone, and saving the result, in the fir ...

Sphere Reflection Captures overridden by Skylight

UE - Graphics Features - Jun 10, 2025

When using non-Lumen lighting and Screenspace reflections off, the skylight location overrides the Reflection Capture location during Build Reflections. This results in a Reflection Capture taken fr ...

Anim State Notifies Don't Consistently Fire Begin/End Events for Looping Anim Sequences

UE - Anim - Runtime - Anim Blueprints - Jun 9, 2025

If you have an Animation Notify State and set it up on an animation to start at the exact beginning of the anim sequence and finish exactly at the end (I have attached a picture of this). It doesn't ...

StructUtils plugin's `FInstancedStruct` in a CPP-defined struct in a `TArray` on an actor component defined in CPP and implemented in BP. Populating the instanced struct in an actor BP's class defaults breaks serialization of the class defaults.

UE - AI - May 30, 2025

Context Instanced structs are great for holding simple data with the main advantage they have is a low memory overhead unlike instanced objects. Problem The problem is in StructUtils plugin's `FIns ...