Unreal Engine Issues
Unreal Engine Issues
HZB Occlusion causes large stalls on the render thread
UE - Rendering Architecture - RHI - Oct 7, 2025HZB Occlusion causes large stalls (greater than 5ms seen) on the render thread due to an RHI flush. This is caused by the following code in FDynamicRHI::RHIMapStagingSurface_RenderThread which force ...
Vertex color does not work on Skeletal Mesh with Nanite enabled
UE - Graphics Features - Nanite - Oct 7, 2025Nanite enabled skeletal meshes don't work with materials containing a vertex color node. The vertex color material does work for non-Nanite skeletal meshes and Nanite-enabled static meshes. ...
Converting a mesh to Nanite merges mesh sections with the same material index, but with different material overrides
UE - Graphics Features - Nanite - Oct 6, 2025When a mesh with multiple sections which point to the same MaterialIndex but have different settings enabled (e.g. bCastShadow is enabled on only one section) is converted to Nanite, the material sl ...
Landscape Textures Patches issue when using "Texture Backed Render Target" as the Height Patch Source Mode where Landscape patches are not applying properly the first time a level is opened after restart
UE - Graphics Tools - Terrain - Landscape - Oct 6, 2025Context: Landscape patches are components that can be attached to meshes to affect the landscape as the mesh is repositioned. Problem: The problem is that when using "Texture Backed Render Target" ...
Recompiling an ABP that another ABP has a Property Access dependency on without recompiling/linking the other causes a crash
UE - Anim - Runtime - Anim Blueprints - Oct 2, 2025The crash comes from the pointers in FAnimSubsystem_PropertyAccess::Library::Indirections in the layer ABP from pointing to old/invalid functions and properties from the trash ABP_Manny, as they hav ...
Update LookupProxy chooser evaluation to work with soft object references.
UE - Anim - Gameplay - Oct 1, 2025Soft object references in proxy tables, when evaluated return a nullptr, instead of the soft object reference to load. ...
FNiagaraScalabilityManager incorrectly reactivates a NiagaraComponent that was deactivated by runtime user code
UE - Niagara - Scalability - Oct 1, 2025Context: The Niagara System is the primary tool to do visual effects inside Unreal. Niagara systems can be culled due to distance. Problem: Once a deactivated Niagara System is culled due to distan ...
Shader Complexity View not working in Deferred Mobile Preview
UE - Platform - Mobile - Sep 30, 2025Proposed workaround:add in FMobileSceneRenderer::RenderDeferredMultiPass (MobileShadingRenderer.cpp): #if WITH_DEBUG_VIEW_MODES if (ViewFamily.UseDebugViewPS()) { return; } #endif // WITH_DEBU ...
BoxOverlapActors fails to catch an Overlaped actor with a particular scale, from a particular position
UE - Simulation - Core - Sep 30, 2025BoxOverlapActors fails to overlap a scaled Floor actor with a particular scale, from a particular position and extent. The setup is really specific and described in Steps to Reproduce. The required ...