Unreal Engine Issues

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 ...

LODs with screen size 0 in legacy assets are incorrectly converted to 1 on load

When loading a mesh asset (static or skeletal) created in an old version of Unreal (e.g. 4.10), any LOD whose LOD screen size was originally set to 0, is converted to 1. This causes LODs that would ...

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 ...

Modifying PostProcess Film Slope can cause TSR to produce ghosting artefacts

When TSR is active, the scene is dark, and a foreground object is lit, modifying the Film/Slope value on a PostProcessVolume can lead to TSR ghosting. TSR occurs prior to Tonemapping, so the issue ...

DOF - TAA pass ghosting when using r.DOF.TAA.CoCBilateralFilterStrength

In Unreal 5.6, there's a new CVar: r.DOF.TAA.CoCBilateralFilterStrength, which should help with ghosting artifacts introduced by TAA in DOF passes. However, it doesn't work as expected since many gh ...

Blurry RVTs after camera jump

When using Runtime Virtual Textures (RVT) on landscape in UE 5.5+, nearby tiles may remain blurry (low-resolution mips) after launching PIE or making large camera jumps (e.g. via bookmarks or viewpo ...