Unreal Engine Issues
Unreal Engine Issues
Lumen Global Distance Field Trace Leaking due to Surface Cache Sampling
UE - Rendering - Graphics Features - Jan 12, 2026At specific distances from a thin wall, surfaces inside of a sealed chamber can receive indirect lighting from outside, leaking light into the chamber. This appears to be due to how SWRT handles sa ...
Call In Editor functions not working in blueprints
UE - Editor - Developer Usability - Dec 19, 2025Context When selecting a component on an actor, any CallInEditor functions on the component's class appear as buttons in the details panel. Problem The CallInEditor functions don't execute in Blu ...
A chaos vehicle that moves at very high speeds with CCD enabled on the vehicle sometimes has a collision response that is abnormal where the vehicle loses a significant amount of speed when colliding with dynamic objects configured as One Way Interaction
UE - Simulation - Gameplay - Dec 16, 2025Context: Continuous Collision Detection (CCD) is being used on a Chaos Vehicle to avoid tunneling issues with certain surfaces as it prevents any missed collisions between fast moving particles and ...
Paper2D: Editor hangs when assigning Sprite Atlas Group to Sprite
UE - Gameplay - Paper2D - Dec 16, 2025In UE 5.3 and later, assigning a Sprite Atlas Group to a UPaperSprite asset can cause the editor to hang and eventually crash. This behavior has been reproduced in 5.3, 5.6, and a recent UE5-main so ...
Issue with Niagara emitter inheritance
UE - Niagara - Dec 4, 2025Modules in the particle spawn stage get unlocked and lose inheritance after changing the inherited emitter's interpolated spawn mode to "No Interpolation" then resetting. ...
Unreal Engine Fails to Launch with Vulkan SM6 RHI and RenderDoc Auto-Attach Enabled
UE - Rendering - Architecture - RHI - Dec 3, 2025When launching Unreal Engine with the Vulkan RHI, SM6 and RenderDoc Auto Attach on Startup enabled, the engine fails to initialize with the error: “A compatible Vulkan Driver is required to run the ...
Chaos sometimes can not generate contact points while two dynamic convex hulls actually collide. It results in instability in the contact behavior - such as jittering, inconsistent contact forces, or unexpected collision responses.
UE - Simulation - Core - Dec 2, 2025Context: Chaos Physics is able to use convex hulls to represent object collision geometry for queries and simulation. Problem: Chaos sometimes can not generate contact points while two dynamic conv ...
Blueprints can enter a corrupted state where Actors construct DefaultSubobjects using CreateOptionalDefaultSubobject, even though child classes call DoNotCreateDefaultSubobject
UE - Framework - Blueprint - Nov 28, 2025Blueprints can enter a corrupted state where Actors construct DefaultSubobjects using CreateOptionalDefaultSubobject, even though child classes call DoNotCreateDefaultSubobject. In some situations, ...
SaveGeneratedTexture2DAsset can crash when overwriting an existing asset
UE - Texture - Nov 28, 2025SaveGeneratedTexture2DAsset can crash for a variety of reasons when overwriting an existing texture asset. When no existing asset exists, the function simply moves the provided transient Texture ass ...
same PhysicsAsset refresh multi times when modify multi SkeletalBodySetup properties in same PhysAsset
UE - Simulation - Gameplay - Nov 20, 2025USkeletalBodySetup::PostEditChangeProperty will call OwningPhysAsset->RefreshPhysicsAssetChange(), if I modify many SkeletalBodySetup properties in same PhysAsset, will cause call OwningPhysAsset-> ...