Sandbox Visitors can fail on empty directories on non-Windows platforms

UE - Foundation - Jul 11, 2024

When a Sandbox Visitor checks a directory and it doesn't exist, it returns true on Windows and false on other platforms. The code that uses the result of this check, IterateDirectory, doesn't conti ...

Integer overflow in NaniteBuilder can lead to an editor crash on certain meshes

UE - Graphics Features - Nanite - Jul 10, 2024

NaniteBuilder uses an int8 type for ExternalEdges and counts adjacency with a int32. The bug stems for the cast to int8 when adding the adjacency count into the ExternalEdges array. The precision l ...

'Max World Position Offset Displacement' causes culling issue on HISMC/foliage in 5.4

UE - Rendering Architecture - Materials - Jul 9, 2024

Foliage/hierarchical instanced static mesh components have issues with culling when their material's "Max World Position Offset Displacement" value is a higher amount, e.g. 100.0. ...

World position offset behaves differently when setting its value directly on the result node

UE - Rendering Architecture - Materials - Jul 8, 2024

The world position offset input of the result node does not behave consistently. There is an obvious visual difference between the setting it by connecting a float3 color constant, versus setting th ...

Incorrect behavior after attaching an actor to a non-root component of another actor in the Editor

UE - Editor - Workflow Systems - Jul 3, 2024

UE allows actors to be attached to other actors. More precisely, it allows the root component of an actor (child) to be attached to any component of another actor (parent). From now on, "parent" and ...

Crash when enabling global logging in 5.4.2

UE - Foundation - Jul 3, 2024

Packaged projects on 5.4.2 (DebugGame) crash immediately on startup when it is opened through the command line using the global logging very-verbose argument. ...

Using Custom Primitive Data as Final Colour in a UI Material crashes the engine with a missing uniform buffer

UE - Rendering Architecture - Materials - Jul 3, 2024

Using custom primitive data as an input in a UI material causes the engine to crash in the RHI thread. The exact crash is "Missing uniform buffer at slot 1, stage SF_Pixel." at Engine\Source\Runtime ...

Bug in StringTemplate.cpp related to modulo operator in MaterialTemplate.ush (code fix provided)

UE - Rendering Architecture - Materials - Jun 25, 2024

Shader Template files like MaterialTemplate.ush do not submit previous chunks when encountering a `%` character, unless that `%` character is `%s` or `% {...} `. Because the error is happening ...

Anisotropy of base disappears when clear coat is greater than 0 when Substrate is enabled

UE - Graphics Features - Substrate - Jun 24, 2024

Anisotropy from the base of a material disappears when clear coat is used. Car paint with base specular_anisotropy at 0.5 and coat at 0.0 [Image Removed] When coat is 0.0: [Image Removed] ...

Editor crash when shader debugging enabled including r.shaders.optimize=0

UE - Rendering Architecture - Shaders - Jun 23, 2024

The editor crashes when activating cvar options for shader compilation and debugging. ...