Unreal Engine Issues
Unreal Engine Issues
Skeleton mesh with hair strands material will lead to unnecessary draw call submissions
UE - Graphics Features - Mar 27, 2025Materials with "Used With Hair Strands" enabled will cause Skeletal Meshes to draw twice in the Base Pass. ...
Masked material using virtual textures covering a decal will result in black pixels
UE - Graphics Features - Nanite - Mar 31, 2025Depth Passes for Masked Materials using Virtual Textures does not work correctly when it is in front of a Nanite Mesh and a Decal, resulting in black artifacts. Also tested on //UE5/Main, CL: 41024 ...
Lack of multi-bounce when using software traced lumen radiosity
UE - Graphics Features - Lumen - Apr 4, 2025Certain 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 ...
Reflection capture doesn't work when using Lumen GI and SSR
UE - Rendering Architecture - Mar 24, 2025Reflection Capture does not appear to work with Lumen + SSR. Licensees have reported that there are cases where they want to combine Lumen GI, SSR and Reflection capture for quality and performance ...
Nanite TwoSidedSign is backwards
UE - Graphics Features - Nanite - Apr 10, 2025The value of MaterialExpressionTwoSidedSign is flipped when calculating the Opacity Mask for Nanite meshes. This seems to be a regression in 5.5. ...
Ensure triggered when creating Scene Proxy for GroomComponent
UE - Rendering Architecture - RHI - Apr 30, 2025When a room component is added in C++ via the actor constructor, an ensure is triggered from precaching and the groom component. Behavior also observed on UE5/Release-5.5, CL: 40988944 ...
Lightmaps are generated even if the ISM component's lightmap type is set to Force Volume
UE - Graphics Features - Jul 30, 2024Insufficient precision of Decode71 function
UE - Rendering Architecture - Shaders - Jun 5, 2025Encode71 and Decode71 in DeferredShadingCommon.ush are functions that convert 8-bit values to 7-bit values and mask values, and licensees have reported that the accuracy is insufficient when usi ...
Niagara mesh particles invalidate lighting when "Cast Shadow" is enabled with Hardware Ray Tracing enabled
UE - Graphics Features - Lumen - Jun 24, 2025Lumen HWRT, combined with Niagara Mesh Renderer, can cause the Lumen Scene to be reset, resulting in a sudden change to indirect lighting. ...
CPU Lightmass generates different lighting results on a landscape if executed via a commandlet vs through the editor
UE - Graphics Features - Jul 3, 2025Building lighting via commandlet and via editor are giving different results. To prevent one method from polluting the other via Swarm cache, the cache needs to be cleared in between tests. ...