Unreal Engine Issues
Unreal Engine Issues
Nanite Voxel material with Static Lighting fails shader compile when r.VelocityOutputPass=1
UE - Rendering - Features - Nanite - Oct 16, 2026Engine/Shaders/Private/Nanite/NaniteVertexFactory.ush:959LightMapCoordinateInput = GetTexCoord(Cluster, uint3(Verts[0].VertIndex, Verts[1].VertIndex, Verts[2].VertIndex), Barycentrics, LightMapUVInd ...
Motion Matching Database editor Preview viewport doesn't display static mesh attachments
UE - MVF Character - Animation - Feb 12, 2024Many of the animation asset editors don't display static mesh attachments in the way that the anim sequence or anim bp editor do. This prevents users from previewing characters that are built from ...
Substrate Adaptive GBuffer: HWRT Hit Lighting drops indirect lighting from lights with a Light Function (GI / Reflections)
UE - Rendering - Features - Shading Models - Oct 22, 2026The Light Function variant of the hit lighting miss shader is compiled as the Light Function material, so MATERIAL_IS_SUBSTRATE=1. This makes it read the ray hit surface from the payload incorrectly ...
FCameraShakePreviewer retains world-outered UCameraShakeBase instances indefinitely, fataling CheckForWorldGCLeaks on editor map change
UE - ACT Character - Sequencer - Aug 21, 2026FCameraShakePreviewer is an FGCObject that strongly references the UCameraShakeBase instances it previews, and creates them outered to the previewed UWorld. Nothing releases them on world teardown, ...
Conflict between sequencer transform track and Parent Constraint from the Animation Mode breaks temporary pivot translation on any actor
UE - ACT Character - Anim in Engine - Jul 15, 2025Note: This affects all versions from at least UE 5.3, including mainline latest. The "Animation" Editor Mode allows creating constraints for level actors. One of these, the "Parent" constraint, con ...
Regarding TObjectPtr performance regression
UE - Core - Systems - Jul 13, 2026This is from the linked EPS case: ============================== When 5.0 first introduced TObjectPtr, the guidance was that it would compile down to raw pointer access in Shipping builds to ensu ...
Chaos: geometry collection with One Way Interaction never breaks from its own collisions
UE - Runtime - Simulation - Aug 21, 2026A geometry collection with One Way Interaction Level set to 0 never breaks from its own collisions. It falls, lands, and stays intact no matter what it hits. Set the level to -1 (feature off) and ch ...
Geometry Collections built with "Use Root Proxies" rendering/transform positions ignore the original root node rotation and can lead to unexpected behaviors
UE - Runtime - Deformable - Nov 17, 2025Geometry Collections (GC) built with "Use Root Proxies" rendering/transform positions ignore the original root node rotation and can lead to unexpected behaviors. If the root node of the GC was rot ...
Proxy Table allows creating a Nested Chooser, but Edit does not open it
UE - Runtime - Animation - Nov 3, 2026A Proxy Table entry allows selecting Nested Chooser and creating an embedded Chooser Table. The new Chooser's name appears in the entry, but clicking Edit does not open it, preventing us from config ...
Chaos Mover crash in standalone editor client
UE - Runtime - Character - Aug 18, 2026When using the Chaos Mover with resimulation enabled, standalone editor processes running as a client will crash around 80% of the time upon startup. ...