Cannot add to Override Materials array of a Static Mesh Component

UE - Graphics Features - May 23, 2017

Materials cannot be added to the Override Materials array in a static mesh component because attempting to add elements to the array fails. Regression: Yes - using the plus button to add to the arr ...

DeltaTime returns inaccurate time when Tick Interval is positive

UE - Gameplay - May 30, 2017

When disabling/enabling tick at runtime, if (TickInterval == 0) then DeltaTime returns as the length of a frame, but if (TickInterval > 0) DeltaTime returns as the length between when tick was disab ...

RecastNavMesh fails to delete when grouped with NavMeshBoundsVolume - Top Down project

UE - AI - May 31, 2017

While testing in //UE4/Release-4.16 CL 3466753 in Binary – I encountered an issue when deleting NavMeshBoundsVolume and RecastNavMesh. The NavMeshBoundsVolume is deleted but the RecastNavMesh remain ...

Transform track can't be edited for Spawnable empty actor in Sequencer

UE - Anim - Sequencer - Oct 2, 2017

Transform track for a spawnable Empty Actor always shows 0, 0, 0 and it can't be edited. I could repro this in 4.17.2 and 4.18 Preview 2. This does not happen in 4.15.3 and 4.16.3. So this could b ...

Adding a camera cut track through sequencer scripting does not set the movie scene's camera cut track

UE - Anim - Sequencer - Mar 13, 2020

When adding a camera cut track through sequencer scripting there is no way to set the camera cut track on the movie scene, which is how the add track menu determines if a new one can be added. This ...

BlackboardComponent observer can be called for the wrong key

UE - AI - BehaviorTree - Feb 7, 2023

We need to, at least, prevent this by clearing observers when running a new BT using a different blackboard. Must also think that this might affect licensees relying on the current behavior (might h ...

TranslucentVolumeAmbient is darkened in InjectTranslucencyLightingVolume pass when using VSMs with r.Shadow.Virtual.ForceOnlyVirtualShadowMaps is Off

UE - Graphics Features - Shadows - Nov 18, 2024

CSM targets are still created and affect the InjectTranslucencyLightingVolume pass when moving in a project that only uses VSM causing over brightening of fog planes and other translucent meshes. r ...

Compiling any material in UE 5.5.1 without ShaderCompiler JobCache results in a crash

UE - Rendering Architecture - Shaders - Jan 15, 2025

Compiling any material with r.ShaderCompiler.JobCache=0 causes ShaderCompileWorker to crash. Reproduction steps cause a crash during Editor startup, but this bug may affect other scenarios where mat ...

Popping Ribbon UVs

UE - Niagara - Mar 10, 2025

Please see the Additional Link for related UDN information. The UV popping described can be subtle, depending on settings; it's affected by spawn rate and GPU vs CPU. The popping shown in the gif t ...

Editor primitives render incorrectly in stereoscopic with instanced stereo

UE - Platform - XR - Aug 17, 2016

Trigger box icons move around when oculus head movement is used. Found in //UE4/Release-Staging-4.13 @ 3090357 QA-Promotion map Edit: 08-22: This affects volumes as well as their editor icons, upd ...