PDI-DrawPoint - Zoomfactor being calculated incorrectly

UE - Graphics Features - Feb 20, 2017

A licensee has reported that the ZoomFactor variable inside of the DrawPoint function is being calculated incorrectly. It currently is calculated using the lesser of the projection matrix's horizont ...

Long thin spinning objects take too long to stop spinning

UE - Simulation - Physics - Solver - Jun 5, 2023

See the SpinningObjectStability test map in the Physics Sandbox. [Link Removed] It's not clear if this is a bug or a side effect of some of our solver shortcuts (e.g., omission of the precession te ...

AreaNavModifiers generated by SplineNavModifierComponent have the component-to-world transform incorrectly applied twice

UE - AI - Navigation - Aug 15, 2025

USplineNavModifierComponent was made available in UE 5.4. It generates several FAreaNavModifier instances covering a region with a certain thickness around a USplineComponent, and worked correctly u ...

FBX animations generated under fractional framerates fail to import

UE - Anim - Runtime - Aug 24, 2022

We now have the following error that is generated in FFbxImporter::ValidateAnimStackif (!FMath::IsNearlyZero(SubFrame, KINDA_SMALL_NUMBER) && !FMath::IsNearlyEqual(SubFrame, 1.0f, KINDA_SMALL_NUMBER ...

Typo in GetAsBoundsArray() from file AABBTree.h on Chaos module

UE - Simulation - Physics - Jul 30, 2025

From file [Engine\Source\Runtime\Experimental\Chaos\Public\Chaos\AABBTree.h], function Chaos::TAABBTree<>::GetAsBoundsArray(): bool GetAsBoundsArray(TArray<TAABB<T, 3>>& AllBounds, int32 NodeIdx, i ...

GeometryCollection clustered by ClusteredGroupIndex does not respect child's gravity setup

UE - Simulation - Physics - Mar 7, 2024

Following code works as a workaround void FClusterUnionManager::HandleAddOperation(FClusterUnionIndex ClusterIndex, const TArray<FPBDRigidParticleHandle*>& Particles, bool bReleaseClustersFirst) ...

Pasting custom data floats from a text editor into a instanced static mesh component crashes the editor

UE - Framework - Components - Aug 5, 2024

When an instanced static mesh component with a material using a PerInstanceCustomData node has its data floats pasted in, the editor crashes with an "Array index out of bounds" error. The licensee w ...

Illegal reference to private object when cooking a child level sequence with a time warp track

UE - Anim - Sequencer - Apr 28, 2025

Slack: [Link Removed] Cook error: UATHelper: Cooking (Windows): LogSavePackage: Warning: UATHelper: Cooking (Windows): Referencers of MovieSceneTimeWarpSection /Game/ChildSequence.ChildSequence: ...

Disabling bLerpUVs in Nanite Settings of Static Mesh causes texture warping in clusters

UE - Graphics Features - Nanite - Jan 21, 2025

The licensee has identified a potential fix by changing if( Settings.bLerpUVs ) to if( Settings.bLerpUVs || UVIndex == 0 ) On line 389 of NaniteBuilder\Private\Cluster.cpp in UE 5.5 ...

Get Material Instance ___ Parameter Value not working for Blend Parameter

UE - Rendering Architecture - Materials - Dec 2, 2022

Reproduced 3/3 times, issue also occurs in //UE5/Release-5.0 - CL 20979098 Binary. Confirmed NOT a Regression. ...