Description

By calling FLODUtilities::SimplifySkeletalMeshLOD on a mesh with cloth sections that is set to remap morph targets, a crash occurs. This seems to be due to the indexing of sections with/without including cloth sections.

Steps to Reproduce
  • Open Content Examples
  • Open the Owen Skeletal Mesh and enable Remap Morph Targets
  • Call FLODUtilities::SimplifySkeletalMeshLOD using the Owen mesh
Callstack

Assertion failed: BaseVertices.IsValidIndex(CornerIndice) [Link Removed] [Line: 268]

UE4Editor_Core!FWindowsErrorOutputDevice::Serialize() [d:\build\++ue4\sync\engine\source\runtime\core\private\windows\windowserroroutputdevice.cpp:79]
UE4Editor_Core!FOutputDevice::LogfImpl() [d:\build\++ue4\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:71]
UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:440]
UE4Editor_Core!FDebug::CheckVerifyFailedImpl() [d:\build\++ue4\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:418]
UE4Editor_UnrealEd!ProjectTargetOnBase() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\lodutilities.cpp:268]
UE4Editor_UnrealEd!FLODUtilities::ApplyMorphTargetsToLOD() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\lodutilities.cpp:674]
UE4Editor_UnrealEd!FLODUtilities::SimplifySkeletalMeshLOD() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\lodutilities.cpp:826]
UE4Editor_UnrealEd!FLODUtilities::SimplifySkeletalMeshLOD() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\lodutilities.cpp:858]
UE4Editor_ContentExamples3!UMyBlueprintFunctionLibrary::ReproMorphLODCrash() [c:\users\dakota.carmer\documents\unreal projects\contentexamples3\source\contentexamples3\myblueprintfunctionlibrary.h:27]
UE4Editor_ContentExamples3!UMyBlueprintFunctionLibrary::execReproMorphLODCrash() [c:\users\dakota.carmer\documents\unreal projects\contentexamples3\source\contentexamples3\myblueprintfunctionlibrary.h:17]
UE4Editor_CoreUObject!UFunction::Invoke() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\class.cpp:4643]
UE4Editor_CoreUObject!UObject::CallFunction() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:904]
UE4Editor_CoreUObject!UObject::ProcessContextOpcode() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:2314]
UE4Editor_CoreUObject!ProcessLocalScriptFunction() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:974]
UE4Editor_CoreUObject!ProcessScriptFunction<void (__cdecl*)(UObject *,FFrame &,void *)>() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:809]
UE4Editor_CoreUObject!ProcessLocalFunction() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:1033]
UE4Editor_CoreUObject!ProcessLocalScriptFunction() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:974]
UE4Editor_CoreUObject!UObject::ProcessInternal() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:1058]
UE4Editor_CoreUObject!UFunction::Invoke() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\class.cpp:4643]
UE4Editor_CoreUObject!UObject::ProcessEvent() [d:\build\++ue4\sync\engine\source\runtime\coreuobject\private\uobject\scriptcore.cpp:1464]
UE4Editor_Engine!AActor::ProcessEvent() [d:\build\++ue4\sync\engine\source\runtime\engine\private\actor.cpp:769]
UE4Editor_Engine!AActor::BeginPlay() [d:\build\++ue4\sync\engine\source\runtime\engine\private\actor.cpp:3383]
UE4Editor_Engine!AActor::DispatchBeginPlay() [d:\build\++ue4\sync\engine\source\runtime\engine\private\actor.cpp:3343]
UE4Editor_Engine!AWorldSettings::NotifyBeginPlay() [d:\build\++ue4\sync\engine\source\runtime\engine\private\worldsettings.cpp:253]
UE4Editor_Engine!AGameMode::HandleMatchHasStarted() [d:\build\++ue4\sync\engine\source\runtime\engine\private\gamemode.cpp:239]
UE4Editor_Engine!AGameMode::SetMatchState() [d:\build\++ue4\sync\engine\source\runtime\engine\private\gamemode.cpp:355]
UE4Editor_Engine!AGameMode::StartMatch() [d:\build\++ue4\sync\engine\source\runtime\engine\private\gamemode.cpp:216]
UE4Editor_Engine!UWorld::BeginPlay() [d:\build\++ue4\sync\engine\source\runtime\engine\private\world.cpp:3946]
UE4Editor_Engine!UGameInstance::StartPlayInEditorGameInstance() [d:\build\++ue4\sync\engine\source\runtime\engine\private\gameinstance.cpp:413]
UE4Editor_UnrealEd!UEditorEngine::CreatePIEGameInstance() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\playlevel.cpp:3341]
UE4Editor_UnrealEd!UEditorEngine::PlayInEditor() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\playlevel.cpp:2466]
UE4Editor_UnrealEd!UEditorEngine::StartQueuedPlayMapRequest() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\playlevel.cpp:1280]
UE4Editor_UnrealEd!UEditorEngine::Tick() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\editorengine.cpp:1532]
UE4Editor_UnrealEd!UUnrealEdEngine::Tick() [d:\build\++ue4\sync\engine\source\editor\unrealed\private\unrealedengine.cpp:403]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4\sync\engine\source\runtime\launch\private\launchengineloop.cpp:3967]
UE4Editor!GuardedMain() [d:\build\++ue4\sync\engine\source\runtime\launch\private\launch.cpp:168]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:145]
UE4Editor!WinMain() [d:\build\++ue4\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:275]
UE4Editor!__scrt_common_main_seh() [d:\agent\_work\3\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
kernel32
ntdll

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Fixed
ComponentOLD - Anim
Affects Versions4.22
Target Fix4.23
Fix Commit5898717
Main Commit5898717
CreatedMay 15, 2019
ResolvedMay 21, 2019
UpdatedJul 10, 2019