Autobrake feature in ChaosVehicleMovementComponent is stopping vehicle from sleeping

UE - Simulation - Physics - Mar 5, 2025

In ChaosVehicleMovementComponent::CalcThrottleBrakeInput, autobrake is set when a vehicle is stopped - this means that when the car is virtually stationary, the BrakeOut inout parameter is always 1. ...

[bug] OIT doesn't work correctly with alpha composite blend mode

UE - Graphics Features - Substrate - Mar 4, 2025

When using OIT, AlphaComposite Materials blend as if they are using the Translucent BlendMode. The order of macro #if … #elif cases cause AlphaComposite Materials to take the same route as Transluce ...

AllowAsyncRenderThreadUpdatesEditorGameWorld/AllowAsyncRenderThreadUpdatesEditor CVars are off by default and unsafe in Niagara

UE - Niagara - Mar 4, 2025

This user made a github pull request: [Link Removed] but it was auto rejected. I think that we can consider taking their fixes, but keeping it disabled by default. ...

FBX import freezes in DataPrep

UE - Editor - Content Pipeline - Visual Dataprep - Mar 3, 2025

FBX file import freezes UE while trying to import into DataPrep by the Interchange importer. The import will start, but then a message will pop up stating "Creating snapshot of world content ... " ...

When using 'r.VT.SplitPhysicalPoolSize 64' with nanite meshes, mesh painting does not update in real time (only updates after stroke finished), duplicates mesh painting across separate instances of a mesh, and sometimes doesn't show up in PIE.

UE - Rendering Architecture - Mar 3, 2025

When using Mesh Painting on nanite meshes in 5.5 with 'r.VT.SplitPhysicalPoolSize' set to non-zero values (e.g. 16, 64), several issues occur, such as: 1. Painting doesn't update in real time (only ...

NiagaraSystem with EniagaraGpuComputeTickStage::PostInitViews rarely crashes due to multi-thread race conflicts

UE - Niagara - Mar 1, 2025

NiagaraSystem with EEiagaraGpuComputeTickStage::PostInitViews should not have bSupportsParallelGDME because of possible multi-threaded contention, but FNiagaraSystemInstanceController::GetGpuCompute ...

Niagara - When Interpolated Spawning is disabled, the first frame of each particle unexpectedly does not take into account the Particle Update stage

UE - Niagara - Feb 28, 2025

Foreword: Even if the behavior described here is by design, it is rarely (if ever) expected or desired. This was discussed and agreed to be treated as a bug. Explanation below. When interpolated sp ...

Shader Symbols not Generated for Windows Platform when r.Shaders.Symbols=1

UE - Rendering Architecture - Shaders - Feb 28, 2025

Shader symbols are not generated for the Windows platform. Attempts were made to set the r.Shaders.Symbols=1 value in the projects DefaultEngine.ini, the engines ConsoleVariables.ini and the engine ...

Virtual Texture Data GetNumMips reports one fewer mip than expected

UE - Graphics Features - Feb 27, 2025

FVirtualTextureBuiltData::GetNumMips() can return 1 fewer mip than it should due to a potential clamping issue at the end of FVirtualTextureBuilderDerivedInfo::InitializeFromBuildSettings() where it ...

OnComponentWake Event does not trigger when the physical body is awoken by a Force

UE - Simulation - Physics - Feb 27, 2025

OnComponentWake Event does not trigger when the physical body is awoken by a Force. The steps described on Steps To Reproduce is enough to replicate this behavior. The OnComponentWake event is only ...