Unreal Engine Issues

Lightmass CalculatePointShadowing regression in UE5.6

There is a regression or change in the Build Lighting process when using Lightmass in Unreal Engine 5.6:When building lighting with Lightmass calling the CalculatePointShadowing function, the result ...

Skylight Leaking Tint in Reflection

From 5.6 onwards, Skylight Leaking is much stronger in reflections than in the world. Also tested on //UE5/Release-5.6, CL 45232827 ...

Race condition in skin cache task wait and GetCachedGeometry

Local Exposure can cause large variations in PreExposure under certain conditions

PreExposure is influenced by LocalExposure in PostProcessEyeAdaptation.cpp:1265. It appears when the scene is particularly dark and using manual exposure, the LastAverageLocalExposure can read a lar ...

Custom fallback mesh LODs for Nanite-enabled meshes not working

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 ...

Downsampled SceneColour textures are not invalidated after ComposeToNewSceneColor when TSR is enabled leading to AfterMotionBlur materials not rendering bloom

When an emissive AfterMotionBlur material is used with TSR, Bloom is not applied to the material. The cause for this appears to be that AfterMotionBlur materials are composed to a separate texture ...

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

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 ...

Modifying the view size can cause TSR history to allocate large amount of memory

When animating the split fraction of a splitscreen experience, TSR causes an significant increase in UAV memory. In PIX, this appears to be caused by TSR allocating the history multiple times when ...

Volumetric lightmap cache point becomes extreme bright if the light source is accidently at the exact(or almost) location of it

Rect Light not rendered correctly when using Virtual Texture as source texture

Licensees have reported that this issue occurs when rendering from the command line: Rectangular lights with virtual textures do not render when you run the "Render (Remote)" button in the Editor, a ...