Raytraced lights with Source Length > 0 behave incorrectly with Megalights

UE - Graphics Features - Ray Tracing - Mar 26, 2025

When Megalights is enabled, light can leak into areas that should be occluded for lights with smallish (5.0) source length and source size. [Image Removed][Image Removed] This was taken with r.Ray ...

Distance Field AO from Moveable Skylight (non-Lumen) invalidates AO incorrectly with a screenspace offset to the right of moving objects

UE - Graphics Features - Mar 25, 2025

When Global Illumination is set to “None” in the project settings the ambient occlusion does not correctly render shadows for moving objects. This has been observed in versions 5.4 and above. ...

Resetting material instance parameters to default value does not update the appearance of the object that the material is applied to

UE - Rendering Architecture - Materials - Mar 10, 2025

When a material instance with exposed parameters is applied to a landscape; the parameters set to a new value and then reset to back the default value, the landscape does not respect the new default ...

Incorrect mesh deformation when Max World Position Offset Displacement used

UE - Graphics Features - Nanite - Feb 12, 2025

When Vertex Animated Texture is used to animate a mesh with World Position Offset, often the Max World Position Offset Displacement Material setting must be increased or the Bounds Scale increased, ...

Mover ensure triggered when engine is running in the background

UE - Gameplay - Player Movement - Mover - Feb 11, 2025

When the engine is running in the background, the following ensure may be hit in NetworkPredictionService_Interpolate.inl: npEnsure(ToFrame == INDEX_NONE || LocalFrame - ToFrame < Frames.Buffer.Cap ...

Ambient occlusion causing ghosting for animations when viewport is resized on DX11

UE - Graphics Features - Feb 10, 2025

Tested regression against //UE5/Release-5.4 @ CL35576357 and the issue did not occur. This is a confirmed regression.[Image Removed] Jira Bot attaches conversation thread from Slack [Image Removed]D ...

[Interchange][FBX] Import model with custom collision prevents socket to be imported

UE - Editor - Content Pipeline - Import and Export - Feb 5, 2025

I would like parity with legacy: 1) only one material 2) socket to be imported Box_Socket file imports same in legacy and interchange: it is just box and socket without collision. ...

COND_InitialOnly property not written to first replay checkpoint after being changed

UE - Networking - Feb 5, 2025

When recording a checkpoint, it is treated as an initial replication, as all the changed properties since the channel was opened need to be recorded. This normally results in any initial only proper ...