Unreal Engine Issues
Unreal Engine Issues
FMovieSceneSkeletalAnimationParams::MapTimeToAnimation returns the wrong value if InFrameRate is not the Tick Resolution
UE - Anim - Sequencer - Jan 16, 2026FMovieSceneSkeletalAnimationParams::MapTimeToAnimation takes in an FFrameTime and FFrameRate and is supposed to tell you which frame of animation that evaluates to, when accounting for looping, play ...
Light Function Materials containing a Texture Sample and Rotator nodes will fail RHI Validation
UE - Rendering Architecture - RHI - Jan 12, 2026Using a Light Function Material that contains a Texture Sample and Rotator nodes will cause RHI Validation to fail with the following error: LogOutputDevice: Error: Ensure condition failed: Bindings ...
WP Builders: The Datalayer states forced in UWorldPartitionBuilder::LoadDataLayers can be lost
A licensee reported that Datalayers that are added to UWorldPartitionBuilder::IncludedDataLayers in a custom builder PreRun are not respected. I used the minimap builder to debug the state of t ...
Not possible to force the Skeleton attribute to None on a default asset pipeline preset
UE - Editor - Content Pipeline - Import and Export - Jan 9, 2026I guess that when the default value of the pipeline is None, the editor will silently pick the skeleton that is in the same folder of where you are importing. If the UI is active you can then force ...
Velocity Scene Texture Data Integrity Issues
UE - Graphics Features - Jan 8, 2026When a Post-Process Material uses the Scene Texture Material Expression, the following code is generated: ``` MaterialFloat2 Local0 = Parameters.TexCoords[0].xy; MaterialFloat2 Local1 = ClampSceneT ...
WP: Water surfaces are missing from the Minimap textures.
UE - Graphics Tools - Terrain - Water - Jan 8, 2026The problem is caused by FWaterViewExtension::ShouldHaveWaterZoneViewData that prevents the water data from being updated in SceneCaptures. (re: FWaterViewExtension::SetupView) Removing the call to ...
It is not possible to export virtual layer masks (AI or from mesh) through the COLMAP exporter.
RS - MVS - Jan 8, 2026Found in 2.1.0.119011 (R210). The mask export doesn't work even when the masks are regenerated from the mesh. Outcome: Error appears: "The filename, directory, or volume label syntax is incorrect ...
Morph Targets fail to reset to zero
UE - Rendering Architecture - RHI - Jan 6, 2026"We have encountered a regression in UE 5.7 where Skeletal Mesh Morph Targets do not visually reset when all weights are set to 0.0. The mesh retains the deformation from the previous frame. This i ...
Out-of-Bounds Access During Partial Updates of ISMC Per-Instance Custom Data
UE - Graphics Features - Jan 6, 2026When using instance custom data values, removing an instance and changing the number of custom data floats in sequence can cause an array-out-of-bounds crash. The underlying arrays are not resized ...
CommonUI: FUITag, FUIActionTag variables can't connect with blueprint wildcard Equals node
UE - Editor - UI Systems - Jan 5, 2026Context UITag and UIActionTag are blueprint-exposed struct classes that derive from GameplayTag. GameplayTag variables can be compared in blueprint with ==. Under the hood, the node maps to UBlue ...