Unreal Engine Issues

Assert crash when playing Groom Cache with Card Mesh LOD

Playing a Guides Groom Cache while Card Mesh LOD (Guide-Based) is active causes an assert in RunHairStrandsInterpolation_Cards when the renderer switches to Card LOD. Assert location:Plugins/Runtim ...

VSM + Nanite Tessellation + Volumetric Fog Shadow leaking while the Directional lighting is rotating

ApplyLocalExposure uses Output_ExtentInverse instead of Output_ViewportSizeInverse for bilateral grid UV

The ApplyLocalExposureCS shader in PostProcessLocalExposure.usf computes UV coordinates for the LumBilateralGrid 3D texture using Output_ExtentInverse (1/RenderTargetSize) instead of Output_Viewport ...

Wrong WPO motion vectors due to Periodic World Space node

We've noticed smearing in grass due to wrong motion vectors. This appears to be caused by lack of previous frame support in the periodic world space node. This is how we fixed it: In MaterialTempl ...

Hair Shadows Not Affecting SSS Back Scattering (Subsurface Profile)

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 ...

Crash when switching from Lumen visualization to raytracing visualization

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 ...

Material Editor Viewport does not display World Position Offset

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 ...

Distance Field Ambient Occlusion artifacts when using dynamic resolution

Distance Field Ambient Occlusion produces artifacts when using Dynamic Resolution at lower framerates. ...

Clear coat bottom normal does not seem to work properly with virtual textures

Clear coat bottom normal does not seem to work properly with virtual textures. Different virtual textures plugged into the material's base color can yield different clearcoat bottom normal results. ...

Clearcoat material behaves differently between 5.5 and 5.7

Starting with Unreal Engine 5.7, specular reflections on clearcoat Materials are less pronounced. Unreal Engine 5.5 tests performed on //UE5/Release-5.5/, CL: 41545209 ...