Bug with Lumen FScene::FindLumenSceneData( | UE 5.2

Hello!

This is the fourth time such a strange bug has occurred.

macbook M1 max UE 5.2

Caught signal

FScene::FindLumenSceneData(unsigned int, unsigned int) const Address = 0x1277ae94c (filename not found) [in UnrealEditor-Renderer.dylib]
ShouldRenderLumenForViewFamily(FScene const*, FSceneViewFamily const&, bool) Address = 0x1272c5ce4 (filename not found) [in UnrealEditor-Renderer.dylib]
Lumen::IsLumenFeatureAllowedForView(FScene const*, FSceneView const&, bool, bool) Address = 0x12729cb20 (filename not found) [in UnrealEditor-Renderer.dylib]
ShouldRenderLumenDiffuseGI(FScene const*, FSceneView const&, bool, bool) Address = 0x127206d7c (filename not found) [in UnrealEditor-Renderer.dylib]
FSceneRenderer::FSceneRenderer(FSceneViewFamily const*, FHitProxyConsumer*) Address = 0x1278cd9d4 (filename not found) [in UnrealEditor-Renderer.dylib]
FDeferredShadingSceneRenderer::FDeferredShadingSceneRenderer(FSceneViewFamily const*, FHitProxyConsumer*) Address = 0x126e42488 (filename not found) [in UnrealEditor-Renderer.dylib]
FSceneRenderer::CreateSceneRenderers(TArrayView<FSceneViewFamily const*, int>, FHitProxyConsumer*, TArray<FSceneRenderer*, TSizedDefaultAllocator<32>>&) Address = 0x1278d58f4 (filename not found) [in UnrealEditor-Renderer.dylib]
FSceneRenderer::CreateSceneRenderer(FSceneViewFamily const*, FHitProxyConsumer*) Address = 0x1278d5bd4 (filename not found) [in UnrealEditor-Renderer.dylib]
CreateSceneRendererForSceneCapture(FScene*, USceneCaptureComponent*, FRenderTarget*, UE::Math::TIntPoint, UE::Math::TMatrix const&, UE::Math::TVector const&, UE::Math::TMatrix const&, bool, float, bool, FPostProcessSettings*, float, AActor const*, int) Address = 0x1278a5964 (filename not found) [in UnrealEditor-Renderer.dylib]
FScene::UpdateSceneCaptureContents(USceneCaptureComponent2D*) Address = 0x1278a3abc (filename not found) [in UnrealEditor-Renderer.dylib]
USceneCaptureComponent::UpdateDeferredCaptures(FSceneInterface*) Address = 0x11a18f504 (filename not found) [in UnrealEditor-Engine.dylib]
FRendererModule::BeginRenderingViewFamilies(FCanvas*, TArrayView<FSceneViewFamily*, int>) Address = 0x1278d94a8 (filename not found) [in UnrealEditor-Renderer.dylib]
FRendererModule::BeginRenderingViewFamily(FCanvas*, FSceneViewFamily*) Address = 0x1278d7ee4 (filename not found) [in UnrealEditor-Renderer.dylib]
UGameViewportClient::Draw(FViewport*, FCanvas*) Address = 0x11a615d48 (filename not found) [in UnrealEditor-Engine.dylib]
FViewport::Draw(bool) Address = 0x11b8e0394 (filename not found) [in UnrealEditor-Engine.dylib]
UEditorEngine::Tick(float, bool) Address = 0x114711edc (filename not found) [in UnrealEditor-UnrealEd.dylib]
UUnrealEdEngine::Tick(float, bool) Address = 0x1154676b8 (filename not found) [in UnrealEditor-UnrealEd.dylib]
FEngineLoop::Tick() Address = 0x104e6c844 (filename not found) [in UnrealEditor]
GuardedMain(char16_t const*) Address = 0x104e78b10 (filename not found) [in UnrealEditor]
-[UEAppDelegate runGameThread:] Address = 0x104e93cd0 (filename not found) [in UnrealEditor]
-[FCocoaGameThread main] Address = 0x1088d53e8 (filename not found) [in UnrealEditor-Core.dylib]
Unknown() Address = 0x1a0fcb54c (filename not found) [in Foundation]
Unknown() Address = 0x19ff7bfa8 (filename not found) [in libsystem_pthread.dylib]
Unknown() Address = 0x19ff76da0 (filename not found) [in libsystem_pthread.dylib]

Hi,

I’m still having this issue as well on Linux (CentOS and Ubuntu). It’s quite random when it happens and seems to be exclusively happening when launching via nDisplay for me. (Though I’m rarely launching otherwise)

[2023.09.14-07.26.36:647][  0]LogCore: === Critical error: ===
Unhandled Exception: SIGSEGV: invalid attempt to read memory at address 0x00000aa367609ce4

[2023.09.14-07.26.36:647][  0]LogCore: Fatal error!

0x00002b1811074c9b libUnrealEditor-Renderer.so!FScene::FindLumenSceneData(unsigned int, unsigned int) const [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Renderer/Private/RendererScene.cpp:1348]
0x00002b181078ef0f libUnrealEditor-Renderer.so!ShouldRenderLumenForViewFamily(FScene const*, FSceneViewFamily const&, bool) [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Renderer/Private/Lumen/Lumen.cpp:122]
0x00002b181078ebe3 libUnrealEditor-Renderer.so!ShouldRenderLumenDiffuseGI(FScene const*, FSceneView const&, bool, bool) [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Renderer/Private/Lumen/LumenDiffuseIndirect.cpp:261]
0x00002b18111d8fc4 libUnrealEditor-Renderer.so!FSceneRenderer::FSceneRenderer(FSceneViewFamily const*, FHitProxyConsumer*) [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Renderer/Private/SceneRendering.cpp:2558]
0x00002b18102a6350 libUnrealEditor-Renderer.so!FDeferredShadingSceneRenderer::FDeferredShadingSceneRenderer(FSceneViewFamily const*, FHitProxyConsumer*) [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Renderer/Private/DeferredShadingRenderer.cpp:516]
0x00002b18111e3434 libUnrealEditor-Renderer.so!FSceneRenderer::CreateSceneRenderers(TArrayView<FSceneViewFamily const*, int>, FHitProxyConsumer*, TArray<FSceneRenderer*, TSizedDefaultAllocator<32> >&) [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Renderer/Private/SceneRendering.cpp:4010]
0x00002b18111e956d libUnrealEditor-Renderer.so!FRendererModule::BeginRenderingViewFamilies(FCanvas*, TArrayView<FSceneViewFamily*, int>) [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Renderer/Private/SceneRendering.cpp:4806]
0x00002b19741b1fe2 libUnrealEditor-DisplayCluster.so!UDisplayClusterViewportClient::Draw(FViewport*, FCanvas*) [/home/ue4/UnrealEngine/Engine/Source/./../Plugins/Runtime/nDisplay/Source/DisplayCluster/Private/Game/EngineClasses/Basics/DisplayClusterViewportClient.cpp:872]
0x00002b17fc5f1942 libUnrealEditor-Engine.so!FViewport::Draw(bool) [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Engine/Private/UnrealClient.cpp:1852]
0x00002b17fc218876 libUnrealEditor-Engine.so!FSceneViewport::ResizeViewport(unsigned int, unsigned int, EWindowMode::Type) [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Engine/Private/Slate/SceneViewport.cpp:1616]
0x00002b17fc217219 libUnrealEditor-Engine.so!FSceneViewport::ResizeFrame(unsigned int, unsigned int, EWindowMode::Type) [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Engine/Private/Slate/SceneViewport.cpp:1494]
0x00002b17fb031e22 libUnrealEditor-Engine.so!UGameEngine::SwitchGameWindowToUseGameViewport() [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Engine/Private/GameEngine.cpp:690]
0x00000000002395b6 UnrealEditor!FEngineLoop::Init() [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Launch/Private/LaunchEngineLoop.cpp:4869]
0x000000000024ebcd UnrealEditor!GuardedMain(char16_t const*) [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Launch/Private/Launch.cpp:166]
0x00002b1801ff8b32 libUnrealEditor-UnixCommonStartup.so!CommonUnixMain(int, char**, int (*)(char16_t const*), void (*)()) [/home/ue4/UnrealEngine/Engine/Source/./Runtime/Unix/UnixCommonStartup/Private/UnixCommonStartup.cpp:269]
0x00002b1802112d90 libc.so.6!UnknownFunction(0x29d8f)
0x00002b1802112e40 libc.so.6!__libc_start_main(+0x7f)
0x0000000000238509 UnrealEditor!_start()

Interestingly it mostly manifests if I launch the 48 nDisplay nodes from the same filesystem at the same time. If I use switchboard to launch them one by one, this error has not occured yet. I’m quite confused.

Hi,
Have you solved this issue? I’m building an nDisplay app, and hitting a similar wall.

Hi,

unfortunately not, I still run into it occasionally even in UE 5.4 nowadays. It’s quite annoying.

I’ve managed to workaround this issue, by switching to the local builds. It constantly bothered me when I used the centralized build that I’ve been starting from the shared drive. So now all my PCs are making their builds (through Switchboard) and I can start all nodes in the cluster instantly (i.e. not one by one) with Switchoboard.

1 Like

This is really interesting news, I suspected that it had something to do with that. So you were also using a shared drive, same as us. I was hoping I could avoid local file systems, but alas this is a great hint and I probably have to also use local builds then.

Are the local builds on their own local drive, or are they still on the shared one for you?