UInstancedStaticMeshComponent::AddInstances does not appear to be adding per-instance previous transforms when enabled

UE - Graphics Features - Dec 3, 2025

Instanced static mesh component does not add instances transforms to PerInstancePrevTransform array when using UInstancedStaticMeshComponent::AddInstances. Additionally Updating the transforms of th ...

Unreal Engine Fails to Launch with Vulkan SM6 RHI and RenderDoc Auto-Attach Enabled

UE - Rendering Architecture - RHI - Dec 3, 2025

When launching Unreal Engine with the Vulkan RHI, SM6 and RenderDoc Auto Attach on Startup enabled, the engine fails to initialize with the error: “A compatible Vulkan Driver is required to run the ...

PlayerCollision visualization incorrect on LandscapeSplineMesh when Nanite is enabled

UE - Graphics Features - Nanite - Dec 3, 2025

From licensee: I’ve found an issue with the visualization of PlayerCollisions when using LandscapeSplineMesh with a mesh that has Nanite enabled. The Chaos collisions shown in the Chaos Visual Debu ...

Pass names appear as "RDGEvent" in Unreal Insights when r.rhisetgpucaptureoptions=1

UE - Rendering Architecture - RHI - Dec 2, 2025

When capturing a trace in Unreal Insights, all r.rhisetgpucaptureoptions=1 (r.RDG.Events=3) all RDG pass events appear simply as RDGEvent, without the actual name due to the logic for RDG_EVENT_SCOP ...

FStateTreeRunParallelStateTreeTask and TStateTreePropertyRef

UE - AI - StateTree - Dec 2, 2025

When using a state tree that has a StateTreePropertyRef as a parameter in parallel any references will fail to resolve using the GetPropertyRef node. ...

Standalone Level Instance with WorldPartition world don't load in editor

UE - World Creation - Worldbuilding Tools - Level Instances - Dec 2, 2025

A WorldPartition map used as a level instance that's set to standalone mode doesn't load its actors in the editor. ...

Not all MidPhases are enumerated in TSimCallbackObject::OnMidPhaseModification

UE - Simulation - Core - Dec 2, 2025

Newly generated MidPhases are copied into the array accessible in the NarrowPhase after the OnPreSimulate callback is invoked. As a result, it is not possible to modify newly created MidPhases withi ...

Memory leak in Landscape edit mode

UE - Graphics Tools - Terrain - Landscape - Nov 28, 2025

PIE also rendering in-active / unfocused editor viewport

UE - Graphics Features - Nov 28, 2025

In 5.8, after entering PIE, the editor will start doing two SceneRenders per frame. This dramatically drops performance. Presumably this second render is for the inactive / unfocused editor viewport ...

SaveGeneratedTexture2DAsset can crash when overwriting an existing asset

UE - Texture - Nov 28, 2025

SaveGeneratedTexture2DAsset can crash for a variety of reasons when overwriting an existing texture asset. When no existing asset exists, the function simply moves the provided transient Texture ass ...