Alembic Skeletal Mesh Crash on FBX Export

Development Pipeline & Plugins
, , , , ,
1

When we try to export a FBX of a skeletal mesh generated via the Alembic importer in 4.13.

Content Browser → Right click → Asset Actions → Export

MachineId:C4EC4FB04ACB2A8FBF8C71B267784019
EpicAccountId:ea24650e01a54002aa8c5df8c0c44082

Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\Build\++UE4+Release-4.13+Compile\Sync\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 833] 
Array index out of bounds: 2 from an array of size 1


UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\misc\outputdevice.cpp:421]
UE4Editor_UnrealEd!UnFbx::FFbxExporter::BindMeshToSkeleton() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\fbx\fbxskeletalmeshexport.cpp:319]
UE4Editor_UnrealEd!UnFbx::FFbxExporter::ExportSkeletalMeshToFbx() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\fbx\fbxskeletalmeshexport.cpp:494]
UE4Editor_UnrealEd!UnFbx::FFbxExporter::ExportSkeletalMesh() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\fbx\fbxmainexport.cpp:912]
UE4Editor_UnrealEd!USkeletalMeshExporterFBX::ExportBinary() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\editorexporters.cpp:1811]
UE4Editor_Engine!UExporter::ExportToArchive() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\unrealexporter.cpp:110]
UE4Editor_Engine!UExporter::ExportToFileEx() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\engine\private\unrealexporter.cpp:414]
UE4Editor_UnrealEd!ObjectTools::ExportObjects() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\unrealed\private\objecttools.cpp:3411]
UE4Editor_ContentBrowser!FAssetContextMenu::ExecuteExport() [d:\build\++ue4+release-4.13+compile\sync\engine\source\editor\contentbrowser\private\assetcontextmenu.cpp:1943]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,FAssetContextMenu,0,TTypeWrapper<void> __cdecl(void)>::Execute() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:317]
UE4Editor_ContentBrowser!TBaseSPMethodDelegateInstance<0,FAssetContextMenu,0,void __cdecl(void)>::ExecuteIfSafe() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:423]
UE4Editor_Slate!SMenuEntryBlock::OnClicked() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:1036]
UE4Editor_Slate!SMenuEntryBlock::OnMenuItemButtonClicked() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:987]
UE4Editor_Slate!TMemberFunctionCaller<SMenuEntryBlock,FReply (__cdecl SMenuEntryBlock::*)(void) __ptr64>::operator()<>() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstanceinterface.h:161]
UE4Editor_Slate!TTupleImpl<TIntegerSequence<unsigned int> >::ApplyAfter<TMemberFunctionCaller<SMenuEntryBlock,FReply (__cdecl SMenuEntryBlock::*)(void) __ptr64> >() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\tuple.h:115]
UE4Editor_Slate!TBaseSPMethodDelegateInstance<0,SMenuEntryBlock,0,FReply __cdecl(void)>::Execute() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegateinstancesimpl.h:317]
UE4Editor_Slate!TBaseDelegate<FReply>::Execute() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:521]
UE4Editor_Slate!SButton::OnMouseButtonUp() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\widgets\input\sbutton.cpp:278]
UE4Editor_Slate!SMenuEntryButton::OnMouseButtonUp() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\multibox\smenuentryblock.cpp:385]
UE4Editor_Slate!<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1>::operator()() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4901]
UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_8d0e9a1da76abd0a756a3a9d775f5ed1> >() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:215]
UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:4890]
UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5348]
UE4Editor_Slate!FSlateApplication::OnMouseUp() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:5328]
UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1584]
UE4Editor_Core!FWindowsApplication::DeferMessage() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:1930]
UE4Editor_Core!FWindowsApplication::ProcessMessage() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:747]
UE4Editor_Core!FWindowsApplication::AppWndProc() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsapplication.cpp:669]
user32
user32
UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\core\private\windows\windowsplatformmisc.cpp:905]
UE4Editor!FEngineLoop::Tick() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\launchengineloop.cpp:2788]
UE4Editor!GuardedMain() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\launch.cpp:156]
UE4Editor!GuardedMainWrapper() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\build\++ue4+release-4.13+compile\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:202]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:264]
kernel32
ntdll
2

Hi BLVD-MTL,

I’ve submitted a ticket for this to be investigated. You can follow the status here: Unreal Engine Issues and Bug Tracker (UE-36602)

Thank you!

Tim

3

Hey Tim,

Thanks you very much for your time, have i noticed the ticked is currently fixed. How can i access to the Fix Commit: 3145222? To patch it on my side?

Thanks for your time,

4

The fix has been implemented in one of our lower streams (Dev-Framework), but has not necessarily been merged back to Main yet. Once the chunk of fixes has been merged to Main you’ll have access to it via GitHub’s Master branch, but I won’t know the specific merge you’ll need to look at, though, since it’ll have multiple CLs and at least should break them up in some readable fashion. I’m just not sure. I don’t mess with GitHub very often.