Scalar Parameter versus Constant placed in Alpha of LERP produces inconsistent results in Blendable

UE - Graphics Features - Jun 8, 2015

When placing a Scalar Parameter into the Alpha position of a LERP you will not get the same results as placing a Constant Value when used in a Post Process Material. Constant Value of 0: [Image Rem ...

Generating Lightmap UVs doesn't automaticly switch LightMapCoord Index

Tools - Jul 17, 2015

When Import a meshes then open the staticmesh editor and turn on the "Generate Lightmap UVs" in the Build Settings. Then hit apply button to genereate the Lightmaps. It will generate the Lightmap bu ...

Line trace fails to detect Destructible Mesh

UE - Simulation - Physics - Destruction - Jun 15, 2015

When using a line trace in the construction script so that objects can return a value destructible meshes will not return a hit. This does not affect use in game with PIE or Standalone game, but if ...

Changing transform of simulated component during physics freezes motion

UE - Simulation - Physics - Oct 13, 2016

If something is executed before a SetActorRotation node on Tick inside of a SceneComponent class BP and then added to an Actor class BP, the physics will lag User Description: When using set rotat ...

Texture Color in UMG reverts to default value after Sequence is over

UE - Anim - Sequencer - May 30, 2017

After the timeline exceeds the sequence, the Material on the image reverts to default Red. This does not happen to the color on the font however. This does Not happen in Main and in 4.16.1 therefo ...

Error when quitting Launch on session - A null object was passed as a world context object to UEngine::GetWorldFromContextObject().

UE - Gameplay - Jun 20, 2017

The following errors occur when the user quits a Launch On session from the editor:LogPlayLevel: QAGame: [2017.06.20-16.26.03:085][292]LogScriptCore: Error: Script Msg: A null object was passed as a ...

Point lights with source length building static lighting in incorrect direction

UE - Graphics Features - Mar 21, 2018

There is an issue where Point lights with source length building static lighting in the incorrect direction, the axis in which the light to be built seem to conflict with the preview build. This iss ...

Subtraction Node wild card inputs incorrectly assigns Time Span data type when given a Date Time data type

UE - Gameplay - Blueprint - Nov 18, 2021

This is a regression //UE4/Release-4.27 has "DateTime - DateTime" and a "DateTime - TimeSpan" node. The subtraction node, with wild card inputs, incorrectly assigns Time Span data type when fed a D ...

Lighting Channels Do Not Function with 78+ Lights on Actor

UE - Graphics Features - Oct 20, 2017

Lighting channels do not function when the number of lights affecting actors is 79 or higher. Any number of lights that is 78 or fewer will honor lighting channel assignments. ...

Translucent Materials no longer reflect light when using Forward Lighting variable

UE - Graphics Features - Jun 7, 2016

Translucent materials are no longer showing light reflections in scene when using r.forwardlighting 1 with lights. This is a regression from functionality in 4.11.2. This no longer works with 4.12 ...