Packed Level Actors will create ISMs with inverted normals when a portion of static meshes have negative scales. This is apparent with two-sided materials.

UE - World Creation - Worldbuilding Tools - Feb 17, 2025

Packed level actors will create ISM instances with inverted normals when the selection of meshes used to create the packed level actor contains a subset of meshes with negative scales. This is the ...

Bundled compute PSO compilation stalling tender thread

UE - Rendering Architecture - RHI - Feb 13, 2025

EA Motive has pointed out a potential bug they found related task graph synchronization and when compiling compute PSOs: [Link Removed]. From the screenshot they sent over, it seems that a task grap ...

Deleting transient actor marks level dirty

UE - World Creation - Worldbuilding Tools - Feb 6, 2025

The licensee has noticed that the deletion of a transient actor still marks the scene as dirty and asks it to be saved. Checking the source it was noted that the transient flag is not verified on de ...

ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision

UE - Simulation - Physics - Jan 27, 2025

ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision. The licensee reports one of their users reported this issue and they were able to reproduce a fe ...

A Skeletal Mesh simulating physics that hits a Geometry Collection Actor with OneWayInteraction true, OneWayInteractionLevel 1, and is using Damage Propagation (default) will be accelerated so fast it immediately disappears by hitting the world limits

UE - Simulation - Physics - Destruction - Jan 20, 2025

A Skeletal Mesh simulating physics that hits a Geometry Collection Actor with OneWayInteraction true, OneWayInteractionLevel 1, and is using Damage Propagation (default) will be accelerated so fast ...

Navigation: Exiting game while async nav building tasks are running can cause null pointer access of OctreeController.NavOctree from worker thread

UE - AI - Navigation - Jan 14, 2025

Context Projects can turn on the project setting bDoFullyAsyncNavDataGathering to execute navigation mesh building tasks on worker threads. Some of these tasks will access the NavOctree, whose life ...

Params in material instance disappear when grouping is changed in material with a material layer

UE - Rendering Architecture - Materials - Jan 11, 2025

If there is a texture parameter within a specific material attribute stream in the base material and also within the base material layer, they must have the same parameter group otherwise the parame ...

A Simulating Physics component with StartAwake = false will be awoken by a Welded component

UE - Simulation - Physics - Jan 10, 2025

A Simulating Physics component with StartAwake = false will be awoken by a Welded component If a welding occurs during the call to OnCreatePhysicsState, this breaks the start awake disabled flag. Th ...

Can't get accurate Anim Notify State elapsed duration while in a montage.

UE - Anim - Gameplay - Dec 13, 2024

When GetCurrentAnimationNotifyStateTimeRatio is used inside of a montage it can return the wrong time ratio in certain cases. ...

Swapping the C++ Root Component from a Child BP class, pressing Save, Compile, but not Saving afterwards, will leave the Root Component in a locked state, meaning the it cannot be viewed or edited in the Details Panel after an Editor restart

UE - Gameplay - Blueprint - Dec 9, 2024

Swapping the C++ Root Component from a Child BP class, pressing Save, Compile, but not Saving afterwards, will leave the Root Component in a locked state, meaning the it cannot be viewed or edited i ...