Parameter metadata not accessible if modified in Material Instance and then converted to CustomPrimitiveData

UE - Rendering - Architecture - Materials - Jun 24, 2026

There’s a potential issue with some changes we made to UMaterialInstance::GetParameterValue (https://github.com/EpicGames/UnrealEngine/commit/8f2bebb008ba645f5938da844cd46b0925322b13). It seems as t ...

Custom expression additional outputs don't work when connected to World Position Offset

UE - Rendering - Architecture - Materials - Jun 24, 2026

Custom expression additional outputs are considered (0,0,0) when connected to WPO. ...

Apply mesh paint Blueprint instance changes and save fails

UE - Rendering - Architecture - Materials - Jun 22, 2026

After mesh painting on a BP Static Mesh Actor, and "Apply instance changes to Blueprint" the added virtual texture is removed with the log:LogTexture: Display: Building texture TwoD: /Game/FirstPers ...

Crash when applying Decal material with Distance Cull Fade node to Decal Actor

UE - Rendering - Architecture - Materials - Jun 15, 2026

The Editor crashes when applying a Material with a Distance Cull Fade node to a Decal Actor. Fatal error: [Link Removed] [Line: 730] Missing uniform buffer at slot 2, stage SF_Pixel. Please check ...

Material Layers cannot be re-ordered by dragging in the Material Layer Parameters tab

UE - Rendering - Architecture - Materials - Jun 9, 2026

Material Layers cannot be re-ordered by dragging in the Material Layer Parameters tab even though there is UI for dragging the rows and the rows appear to be draggable. ...

Editor crashes when Material Layer visibility is toggled after removing a Material Layer in Parent

UE - Rendering - Architecture - Materials - Jun 9, 2026

When a Material Layer is removed from a Parent Material, the Parent Material updates correctly in the viewport, but any Child Material Instance do not update correctly in the viewport until the Chil ...

Adding/Removing a Material Layer on a Parent Material doesn't propagate to Children correctly

UE - Rendering - Architecture - Materials - Jun 9, 2026

When a Material Layer is added to or removed from a Parent Material the layer changes don’t automatically propagate to Child Materials correctly even if the Parent Material is saved. The Child mate ...

Toggling Material Layer visibility in Parent Material doesn't propagate to children

UE - Rendering - Architecture - Materials - Jun 9, 2026

When Material layer visibility is toggled on the Parent Material in a Material hierarchy, only the Parent’s layer visibility is affected, the children are not. Saving the Parent material has no effe ...

Curve Atlas Row Parameter uses derivative ops when Texture Sample connected to curveTime input

UE - Rendering - Architecture - Materials - May 1, 2026

When a Curve Atlas Row Parameter node is used with a Texture Sampler connected to the curve time input, the sample type uses derivative ops. This has negative performance implications for Nanite co ...

GetStaticComponentMaskParameterValue returns the value for Static Switch Parameter

UE - Rendering - Architecture - Materials - Apr 24, 2026

UMaterialInterface::GetStaticComponentMaskParameterValue gets the parameter value from the static switch list instead of from the StaticComponentMask list GitHub branch 5.8 still looks to have this ...