Unreal Engine Issues

UMaterialFunctionInterface not being tagged as BlueprintType makes some editor scripting scenarios difficult

UMaterialInterface is BlueprintType, but UMaterialFunctionInterface is not. This makes it difficult to port some BP logic that works with materials to the material layer system. Crystal Dynamics wou ...

Unable to change Actor Coloration View Modes in PIE

When in PIE changing Actor Coloration view modes from the viewport visualisation mode [Liit] -> [Actor Coloration] -> ... Does not update correctly when switching view mode and sometimes isn't corr ...

Structured log automated decimal number tests fail in languages / cultures that use commas instead of periods

The following Localisation Tests in "Engine\Source\Runtime\Core\Tests\Logging\StructuredLogFormatTest.cpp:275" TestLoc(LOCTEXT("Float", " {Float} "), ANSITEXTVIEW(R"(128.25)")); TestLoc(LOCTEXT ...

Performance slowdown when ray tracing is disabled due to SetResidencyPriority

When a game is compiled with ray tracing disabled (D3D12_RHI_RAYTRACING=0) and the GPU the game is running on becomes low on VRAM, frame time is negatively impacted and doesn't recover. The D3D12_RH ...

Enabling Substrate causes MaterialGraph node previews to render black

Node previews in MaterialGraph with Substrate enabled render solid black in 5.6. The latest 5.5 engine does render previews correct with substrate enabled. ...

Niagara Regression - Looping particle with Spawn Burst Instantaneous on time 0.0 flickers for a frame between loops

Note: This worked correctly up to UE 5.4, but repros from UE 5.5 up to mainline latest. If a Niagara Emitter is set up with "Spawn Burst Instantaneous" on time 0.0, and the spawned particle(s) have ...

Adding vertex color to a model that has morph targets, removes or invalidates the morph targets.

Inconsistent texture loading issue within material editor

A licensee has reached out via EPS about a texture loading issue they are having in-editor. I summarized the most important points below:The issue relates to texture load failure associated with mat ...

URuntimeVirtualTextureComponent::RequestPreload not working for some edge cases

A licensee has reached out to us to inform us that the logic for preloading at times fails to account for adaptive virtual textures when the requested mip level is not in the shared AllocatedVirtual ...

Conflict between sequencer transform track and Parent Constraint from the Animation Mode breaks temporary pivot translation on any actor

Note: This affects all versions from at least UE 5.3, including mainline latest. The "Animation" Editor Mode allows creating constraints for level actors. One of these, the "Parent" constraint, con ...