FHLSLMaterialTranslator::GetMaterialEnvironment can crash or not load UMaterialParameterCollections

UE - Rendering Architecture - Materials - Apr 30, 2025

In UE 5.5, the Editor may crash in FHLSLMaterialTranslator::GetMaterialEnvironment when loading materials with Material Parameter Collections, likely due to async loading. Calling ParameterCollectio ...

Crash when attempting to change the parent of a material instance constant through editor scripting

UE - Rendering Architecture - Materials - Apr 9, 2025

The built-in class "UMaterialEditingLibrary" provides various editor scripting functions related to creating and editing materials and material instances. One of these functions, UMaterialEditingLib ...

Sampling textures with bias in the path of a custom data pin causes derivative operations when avoidable

UE - Rendering Architecture - Materials - Apr 8, 2025

Materials that make use of the analytical derivatives path to avoid hardware derivatives can still generate derivative operations on texture samples when the shading model has a custom data pin and ...

WPO bug with Material Layers

UE - Rendering Architecture - Materials - Apr 7, 2025

I find that there are a couple of things that influence the artefact If WPO in M_BlendingBug is connected I get an issue with the blending. Removing the opacity input that's passed through the ma ...

Crash when Undo after deleting a Material Layer of a Material Instance.

UE - Rendering Architecture - Materials - Apr 2, 2025

In Unreal Engine version 5.5.4, the Editor crashes when performing Undo after deleting a Material Layer of a Material Instance ...

Material Layers Relink Button Missing

UE - Rendering Architecture - Materials - Mar 26, 2025

The Relink button is missing (as are the Save Sibling and Save Child buttons) on Material Instances that use Material Attributes Layers in 5.5. ...

High Virtual Texture Sample/Lookup Cost when using a Virtual Texture in a Material Layer Blend

UE - Rendering Architecture - Materials - Mar 14, 2025

Some Material Attribute blends in Material Layer Blends can cause Virtual Texture samples to be duplicated in HLSL. This can be avoided by sampling the Virtual Texture in the Parent Material, and pa ...

Resetting material instance parameters to default value does not update the appearance of the object that the material is applied to

UE - Rendering Architecture - Materials - Mar 10, 2025

When a material instance with exposed parameters is applied to a landscape; the parameters set to a new value and then reset to back the default value, the landscape does not respect the new default ...

Crash when creating a Material Instance of a Material with Material Attribute Layers expression connected to a Substrate Convert Material Attributes.

UE - Rendering Architecture - Materials - Mar 8, 2025

A UDN user has reported this crash [Link Removed] The user also reports that the editor will crash:If the material is loaded while in PIE.If the material is used in a level (crash occurs when the l ...

Shader info strings overlap in MaterialInstanceEditor and are unreadable

UE - Rendering Architecture - Materials - Jan 24, 2025

CL-35369646 changed the debug information string to span multiple lines, but the Y offset moves forward by only one line, so the string overlaps. ...