Compatible Skeleton Animation does not retarget the same on duplicate skeleton

UE - Anim - Rigging - Retargeting - Jan 29, 2026

If a mesh is exported from the engine, reimported as a new skeleton and mesh, and then marked as a compatible skeleton. Animation will have slightly different rotations playing on the skeleton. ...

Texture streaming uses ISM component bounds instead of closest ISM instance

UE - Rendering Architecture - Jan 22, 2026

When regular texture streaming is used (not virtual textures), the largest mips are always loaded for ISM mesh textures whenever the camera is inside the bounds of the ISM even if the instances are ...

Rotated RetainerWidget does not account for rotation during hit testing

UE - Editor - UI Systems - Jan 21, 2026

Hit testing for widgets contained within a RetainerWidget does not correctly account for rotation applied via render transforms . While the content renders with the expected rotation, hover and clic ...

UEditorEngine::OnAllPIEInstancesStarted() called prematurely, multiple times, while PIE clients are starting

UE - Gameplay - Jan 21, 2026

Context UEditorEngine::OnAllPIEInstancesStarted() is a virtual function that gets called when launching Play-in-Editor. It can be overridden if the game project chooses to introduce a subclass of U ...

Sequencer: Camera blends restore to incorrect view target after Keep State

UE - Anim - Sequencer - Jan 20, 2026

When a Level Sequence’s Camera Cut track with When Finished = Keep State is played, the “original state” is persisted into the PreAnimatedStorage array inside FPreAnimatedCameraCutStorage. From the ...

Material Analyzer misreports static params for Material Layers

UE - Rendering Architecture - Materials - Jan 20, 2026

When analyzing materials that use Material Layers, Material Analyzer reports that multiple Material Instances “share the same static parameter array” and therefore recommends reparenting so that onl ...

[Enhanced Input] The action instance data is incorrectly reset when you call "Add mapping context" on the same mapping multiple times

UE - Gameplay - Input - Jan 16, 2026

This is somewhat related to [Link Removed] Closed and was brought up by a [Link Removed] Setting the CVar input.bRespectIM ...

FMovieSceneSkeletalAnimationParams::MapTimeToAnimation returns the wrong value if InFrameRate is not the Tick Resolution

UE - Anim - Sequencer - Jan 16, 2026

FMovieSceneSkeletalAnimationParams::MapTimeToAnimation takes in an FFrameTime and FFrameRate and is supposed to tell you which frame of animation that evaluates to, when accounting for looping, play ...

Character unnecessary step down during PHYS_Flying mode

UE - Gameplay - Player Movement - Jan 15, 2026

When MovementMode is set to PHYS_Flying, the character may unexpectedly step down by MaxStepHeight when colliding with a wall near a ceiling. This occurs because UCharacterMovementComponent::StepUp ...