Soft angular constraints solve velocity like hard constraints

UE - Simulation - Core - Jul 17, 2025

Soft angular constraints are solving velocity like hard constraints. Instead of swinging back and forth, the affected body just snaps to 45 degrees. Check the steps to reproduce for more details. Th ...

Runtime Virtual Texture samples at low precision for very large volumes

UE - Graphics Features - May 31, 2022

When using a runtime virtual texture with a resolution of greater than 2^24 we can start to see a lack of precision in sampling when the sampling UVs get closer to 1. To see this we need to be usin ...

Raw Input plugin fails to process some negative values

UE - Gameplay - Input - Aug 22, 2023

Came from a UDN: [Link Removed] Proposed fix is to change `FRawInputWindows::ParseInputData` to use this logic instead: ``` ... USHORT BitSize = ValueCapsBuffer[iValue].BitSize; LONG SizeMask ...

Crash when moving map assets used as level instances

UE - World Creation - Worldbuilding Tools - Level Instances - Mar 10, 2025

Custom fallback mesh LODs for Nanite-enabled meshes not working

UE - Graphics Features - Sep 15, 2025

Creating a custom fallback mesh with LOD for Nanite-enabled meshes with multiple materials, results in mesh LODs with errors. As the number of material sections (material slots) decreases with coars ...

SkyLight Leaking does not affect reflections when the SkyLight is static but static lighting is disallowed

UE - Graphics Features - Sep 10, 2025

Reflections do not receive SkyLight leakage contribution from a static SkyLight when static lighting is disallowed. This is caused by the function UpdateSkyIrradianceGpuBuffer checking if the SkyLig ...

NaN Present on IOS after UE5.6 Because of Removal of MobileSpecularGGX

UE - Platform - Mobile - Sep 24, 2025

In UE5.6 MobileSpecularGGX was removed and now mobile devices also run D_GGX. The problem is that there are still cases where very bright values are produced (image 1) and thus NaNs appear in the Bl ...

Changing the Global Time Dilation to a very small value and returning it to a large value (by either using the slomo console command or directly in BP) makes Physics simulating ragdolls fly off into space.

UE - Simulation - Core - Sep 26, 2024

Changing the Global Time Dilation to a very small value and returning it to a large value (by either using the slomo console command or directly in BP - slomo sets TimeDilation) makes Physics simula ...

Niagara crash when using a particle attribute reader that has been passed around between modules

UE - Niagara - Oct 28, 2025

The following Niagara usage pattern results in either a crash or in incorrect data being read from a Particle Attribute Reader: Emitter Spawn Stage – A module has an Attribute Reader input specifie ...

WPO is incorrectly generated on materials using Material Attributes as input to Landscape Layer Blend node

UE - Rendering Architecture - Materials - Jan 31, 2024

This comes from this UDN : [Link Removed] It occurs with this setup :  [Image Removed] , where Set Material Attributes expressions act as inputs to the Landscape Layer Blend material expression. ...