Hair Shadows Not Affecting SSS Back Scattering (Subsurface Profile)

UE - Rendering - Graphics Features - Mar 30, 2026

Groom strands do not appear to correctly block transmitted light for Subsurface Scattering Profile Materials. In some cases, not only will they not block the light, but can instead lead to more ligh ...

Issue with r.SkyAtmosphere.TransmittanceLUT.UseSmallFormat

UE - Rendering - Graphics Features - Mar 30, 2026

When "r.SkyAtmosphere.TransmittanceLUT.UseSmallFormat=1", some values for the Sky Atmosphere at some directional light angles can lead to the sun disk being cut off, and taking on a chord shape. A ...

Crash when switching from Lumen visualization to raytracing visualization

UE - Rendering - Graphics Features - Mar 27, 2026

When switching from Lumen visualization to raytracing visualization via the console, the editor can crash to desktop. The crash appears to happen deep within the driver libraries, and does not trig ...

Editor crash in HairStrandsMeshProjection.cpp when spawning actor with Groom Component bound to skeletal mesh

UE - Rendering - Graphics Features - Mar 23, 2026

The editor crashes with an assertion failure when placing a Blueprint actor that contains a Groom Component bound to a MetaHuman skeletal mesh. The crash occurs in AddHairStrandInitMeshSamplesPass d ...

Material Editor Viewport does not display World Position Offset

UE - Rendering - Graphics Features - Mar 19, 2026

The preview Viewport in the Material Editor does not correctly render World Position Offset. It appears that the RenderVelocities pass (which is also drawing the depth for the preview sphere) does ...

Substrate Unlit editor view mode renders black with Blendable GBuffer

UE - Rendering - Features - Shading Models - Mar 18, 2026

When using Substrate materials with SUBSTRATE_GBUFFER_FORMAT==0 (Blendable GBuffer), the Unlit editor view mode renders completely black. TopLayerData.UnlitViewBaseColor is never populated in the bl ...

Control Rig Physics world collision fails against ISM component meshes

UE - Anim - Synthesis - Physics Control - Mar 17, 2026

CRP currently fails to collide against the bodies generated by ISM components. This is because the collision body data is stored in a different property for ISMs vs regular primitive components. ...

AnimNode content is not applied during PIE when s.AsyncLoadingThreadEnabled is enabled

UE - Runtime - Anim BP - Mar 16, 2026

When the following setting is added to DefaultEngine.ini, the AnimNode content is not applied during PIE execution.[/Script/Engine.EditorStreamingSettings] s.AsyncLoadingThreadEnabled=True If the A ...