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 ...

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 ...

Overlay materials stop working when Show Collisions

UE - Simulation - Physics - Apr 7, 2025

Overlay Materials are disabled when the Collision showflag is enabled. ...

Network Prediction crash when smoothing service instance data is reallocated out from under FNetworkPredictionStateView

UE - Gameplay - Network Prediction - Apr 4, 2025

Received a report from a licensee using Network Prediction Plugin and Mover.  There is a strong likelihood of a crash occurring when using NPP's smoothing option and spawning new NPP-simulating ins ...

Lack of multi-bounce when using software traced lumen radiosity

UE - Graphics Features - Lumen - Apr 4, 2025

Certain Lumen Hardware Ray Tracing CVars, when disabled in isolation, will not fall back to tracing the Global Distance Field, because the Global Distance Field is still disabled. The function "Lum ...

Object Tracks in SubSequencer Lose References When Blending is Enabled

UE - Anim - Sequencer - Apr 4, 2025

We're encountering an issue when using object tracks in subsequencer. When enabling blending on a subsequencer section, the object reference resets throughout the entire duration of the track. Inte ...