Unreal Engine Issues

Lumen artifacts on splitscreen during camera cuts

A UDN licensee has pointed out that they are seeing unresolved Lumen reflection artifacts when they are running their game in split-screen mode. A video of this behavior is found in the Related tab ...

bStaticWhenNotMoveable in Lighting category instead of Physics

"UPrimitiveComponent::bStaticWhenNotMoveable"'s category is set to Lighting, not Physics. This causes it to be hidden when lighting-related properties are hidden, even though it controls physics sta ...

Toggling Vertex Colors on in Static Mesh Editor makes the viewport all white

When turning on the Vertex Color option in the static mesh editor, the whole viewport turns white. ...

Generate Lightmap UVS Doesn't Update the Lightmap Coordinate Index

When importing an fbx file and using 'generate lightmap uvs', the light map coordinate index will not update correctly. Working properly in 4.19 CL# 4033788 Found in 4.20 CL# 4212847 and 4.21 CL# ...

Number containers do not correctly parse equations

In C++, arithmetic operators * and / have the same priority and therefore should be resolved left to right. In this case, * is being resolved first and / second. 1/128*128 and (1/128)*128 should p ...

Ray tracing in sequencer causing AO ghosting

Crash in FPBDJointUtilities::ConditionInverseMassAndInertia

We seem to be setting the InverseInertia to zero, even though the InverseMass is non-zero. FPBDJointUtilities::ConditionInverseMassAndInertia assumes that the inverse inertia is only zero if the in ...

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 ...

Clearcoat shader disappears if any asset using the Material leaves lighting

Clearcoat Shader will stop receiving lighting information if any mesh assigned the material using the shader leaves lighting. Also Reproduced in Launcher 4.9 Preview 4, Main-CL-2660934 [Image Remo ...

German keyboard layout does not recognize the keys ö,ü,^ in editor

ö,ü,^ keys are not recognized on keyboards with a german QWERTZ layout in editor. ...