Crash when changing window resolution with AMD GPU, D3D11 and renderoffscreen

UE - Rendering Architecture - RHI - Apr 9, 2025

Context A crash can be induced with running Unreal Engine with DirectX11, a AMD GPU and running -renderoffscreen flag, and the main window is resized. This issue was first observed with the PixelStre ...

Iris - large fast arrays serialize multiple elements when only one is dirtied

UE - Networking - Iris - Apr 8, 2025

This seems to be a result of how the changemask is handled for fast arrays. Because the changemask is a fixed set of bits (defined by IrisFastArrayChangeMaskBits), a single bit can represent multipl ...

Bug when loading an external project that also exists in the uprojectdirs

UE - Foundation - Cpp Tools - Apr 8, 2025

When launching the editor for the "external\foreign" project, the code in GetEngineAndProjectAbsoluteDirsFromExecutable ends up superseding the path returned from {{FPlatformMisc::ProjectDir() }} wi ...

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 ...

Incorrect volume bounds check in FTranslucentLightInjectionCollector::AddLightForInjection

UE - Graphics Features - Apr 8, 2025

The 'VolumeBounds' array in FTranslucentLightInjectionCollector::AddLightForInjection is accessed as a pointer instead of with 'VolumeCascadeIndex' and thus fails bounds checks for the outer volume. ...

Memory Leak When Raytracing Enabled with Specific Rendering Settings

UE - Graphics Features - Ray Tracing - Apr 8, 2025

When a shipping build is packaged using specific rendering settings a memory leak can be observed. The licensee has noted that this leak presents as a 10MB per hour increase in RAM usage. It has a ...

Niagara - "Make Static" nodes do not seem to be working correctly.

UE - Niagara - Apr 7, 2025

When a "Make Static" node is used in a Niagara Function Script or Niagara Module Script to supply the input value for a Static Switch Selector or, a Function Parameter, or a Function Parameter Defau ...

On the Details Panel of Niagara Function Inputs, the Type selector does not show "Static" types.

UE - Niagara - Apr 7, 2025

Consider a Niagara Function or Module Script containing a Static Switch node. If the "Expose as Pin" option is enabled for its selector variable, an input pin with type "static bool" appears. In one ...

Niagara - When a Static Switch is used inside a Niagara Function Script with "expose as pin" disabled, its Selector variable is exposed as an input on function call nodes. However, this input incorrectly loses its "static" type.

UE - Niagara - Apr 7, 2025

Consider a Niagara Function Script containing a Static Switch node with the "Expose as Pin" option disabled for its selector variable. When the function is called by another Niagara Function or Niag ...