Unreal Engine Issues
Unreal Engine Issues
"FVector contains NaN" on packaged builds for Debug configuration
UE - Rendering - Features - Lumen - May 6, 2022Customer Provided Description:This was experienced in UE 5.01 - custom installed engine (No changes to UE code, simply added the Debug build configuration, see the following command): "c:%ue_dire ...
[Sound Submix] - Dry Level of a Submix is calculated differently whether or not there is an effect in the chain
UE - Audio - Submixes - Jan 21, 2021There is a discrepancy is how the output volume of a submix is calculated when the effect chain is and is not populated. When there is no effect on the submix, the Dry Level adds additional gain to ...
Invalid GUIDs on new material instance parameters cause overrides to break on base param rename
UE - Rendering - Architecture - Materials - Sep 3, 2025When a parameter value is assigned on a newly created material instance (constant or dynamic) using Set***ParameterValueInternal, the parameter’s ExpressionGUID is left invalid (0,0,0,0). Parameter ...
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 ...
Adding a Reroute node to a function's array output will cause the Function node to be missing the output
UE - Gameplay - Blueprint - Mar 26, 2015Adding a Reroute node to a function's array output will cause the Function node to be missing the output. This seems to be only effecting Arrays. Standard variables work fine. ...
Set Ignore Look Input stacks the resulting value each time it is called
UE - Gameplay - Jan 5, 2015Set Ignore Look Input stacks the resulting value each time it is called. If Set Ignore Look Input is called more than once with the same value, it will take as many calls with the opposite value to ...
Setting a parent and child static mesh scale to negative effects the rotation on child when Snapped To Floor
UE - Gameplay - Jul 21, 2016Setting a parent and child static mesh scale to negative effects the rotation on child when Snapped To Floor Looks to be directly related to this JIRA: https://jira.ol.epicgames.net/browse/UE-3152 ...
Global SkyAtmosphere and Clouds Issues (Cloud Shadows)
UE - Rendering - Features - Dec 3, 2024Sampling Cloud Shadows when rendering the Sky Atmosphere can incorrectly assume that the view is located at the planet's North Pole. This causes distortion in the shadows when using a sphere-shaped ...
Native default subobjects nulled in child Blueprints on compile
UE - Framework - Blueprint Compiler - Oct 25, 2021From reporting UDN: "We had a weird issue with new components added in C++ not being instanced properly on non-direct Blueprint children. It seems to happen if loading of the parent BP is deferred ...
r.VolumetricRenderTarget.PreferAsyncCompute producing different visuals
UE - Rendering - Features - Aug 2, 2024When the cvar "r.VolumetricRenderTarget.PreferAsyncCompute" is enabled, it will cause Volumetric Clouds to ignore the influence of Volumetric Fog. In high-fog environments, this can cause the clouds ...