Custom Primitive Data on BP instance not taking affect while in editor

UE - Rendering Architecture - Apr 5, 2023

Original Repo is from 4.27, however, it still happens in 5.2. This is happening because the Instance Data system does not update the field UPrimitiveComponent::CustomPrimitiveDataInternal from the d ...

ES3.1 preview causes temporary freezing when selecting objects in the viewport on Mac

Tools - May 3, 2019

The editor will freeze for seconds at a time when selecting between objects in the viewport after using ES3.1 preview on a Mac. ...

Morph target for SK_BoxMorph_1 exceeds 1.0, causes the sphere shape to bend inward

Docs - Samples - Jul 10, 2017

In Content Examples, the morph targets assigned to SK_Box_Morph_1 exceed 1.0. While it's not "wrong" for morphs to go beyond that, it doesn't seem like it's a great demonstration in the asset. Goi ...

MaterialCurve of AnimSequence is not working with LOD 1~ if assigned Material manually

OLD - Anim - Apr 3, 2015

MaterialCurve of AnimSequence is not working with LOD 1~ if assigned Material manually. Assigning material to LOD0 seems sharing material info with other LODs but material info is never shared if as ...

Particle AnimTrails do not render on Android with Mali chipset when using OpenGL ES 3.1

UE - Platform - Mobile - Nov 22, 2016

Particle AnimTrails are not rendering on Mali but will render on the Adreno when using the OpenGL ES 3.1. ES2 renders correctly on both devices, just ES 3.1 does not. The devices compared: Working ...

MRQ - MovieGraphEditorExample.py on_executor_finished_delegate not called in 5.6

UE - Virtual Production - Tools - MRQ - Jun 13, 2025

From UDN: We are launching jobs using a modified version of MovieGraphEditorExample.py. In 5.5 everything works fine, but in 5.6 the on_executor_finished_delegate is never getting called when all th ...

Setting Physics Blend Weight to anything between 0 and 1 causes erratic behavior

UE - Simulation - Physics - Jul 27, 2015

If the user simulates all bodies, and then sets the physics blend weight to a decimal value between 0 and 1, the skeletal meshes will spin out of control. This doesn't happen if the physics blend w ...

ChaosCacheManager is not reproducing Trailing Events

UE - Simulation - Physics - Mar 28, 2025

ChaosCacheManager (CCM) is not reproducing Trailing Events. Particles set to track Trailing Events correctly follow the position of the trailing event when the Geometry Collection (GC) is physically ...

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 ...

Nanite Instanced Static Meshes lost selection outlines in UE5.5

UE - Graphics Features - Nanite - Mar 6, 2025

Nanite ISMs lost selection outlines in UE5.5 Actors having an ISM component which uses a static mesh with nanite do not get a selection outline when selected in the editor. Having Nanite is essentia ...