Artifacts appear on translucent particle systems during camera motion blur

UE - Rendering Architecture - Jul 23, 2025

Translucent particle systems exhibit visual artifacts when the camera moves, even though motion vectors are disabled for the particle emitters. While switching the Translucency Pass to "After Motio ...

ACineCameraAttachMount's "Target Actor" constraint does not work with Spawnables or Replaceables in Sequencer

UE - Virtual Production - Tools - Virtual Camera - Aug 12, 2025

Constraints (UTickableConstraint) are usually created throuh the "Animation" tab available in the Editor's "Animation Mode". When created through that interface while Sequencer is open, the internal ...

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected

UE - Rendering Architecture - Materials - Aug 24, 2025

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected. The licensee noticed this in a ...

Landscape Textures Patches issue when using "Texture Backed Render Target" as the Height Patch Source Mode where Landscape patches are not applying properly the first time a level is opened after restart

UE - Graphics Tools - Terrain - Landscape - Oct 6, 2025

Context: Landscape patches are components that can be attached to meshes to affect the landscape as the mesh is repositioned. Problem: The problem is that when using "Texture Backed Render Target" ...

Niagara crash when using a particle attribute reader that has been passed around between modules

UE - Niagara - Oct 28, 2025

The following Niagara usage pattern results in either a crash or in incorrect data being read from a Particle Attribute Reader: Emitter Spawn Stage – A module has an Attribute Reader input specifie ...

Plugin fails to compile in 4.11 due to redefinition errors

UE - Foundation - Cpp Tools - Plugin System - May 10, 2016

Plugin fails compile in 4.11 / 4.12 due to redefinition of class/struct type (locally). AH user reported LNK2005 error when compiling in 4.11 Regression: YES? - Project with the attached plugin co ...

Trigger Volume Blocks First-Person Template Projectile

UE - Simulation - Physics - Nov 2, 2015

When playing in editor, if you fire your weapon at a trigger volume, the projectiles will bounce off of the volume, regardless of the fact that the collision is set to Query Only. This collision als ...

Ragdoll Physics do not Function Properly on a Mirrored Skeletal Mesh

UE - Simulation - Physics - Dec 1, 2015

Selecting the default character/skeletal mesh (or any skeletal mesh) in the viewport, right-clicking and transforming it so it mirrors on the X,Y, or Z axis will cause the physics to act erratically ...

Blueprints components setup through code cannot have the parent socket set inside the blueprint

UE - Gameplay - Blueprint - Aug 28, 2015

If a component is created/setup through code and set as the child of a mesh component, clicking the magnifying glass in the Parent Socket field does not bring up the list of mesh sockets to attach t ...

Collision Boxes not set properly when using negative values

UE - Simulation - Physics - May 15, 2015

When using multiple collision boxes with the mesh scaled in a negative axis while the collision boxes are rotated that the rotation is not taken into account when using the negative scale. ...