Description

When creating a static mesh from a Procedural Mesh Component that has been used by a Create Mesh Section node, the editor crashes. The editor doesn't crash when selecting the Create Static Mesh button without the Create Mesh Section node added to the Construction Script.

Tested in //UE4/Release-4.25 @ CL 14469661 and this occurred as well, so not marking as a Regression.

Steps to Reproduce
  1. Open/Create a project
  2. Create a new Actor Blueprint Class
  3. Add a Procedural Mesh component
  4. In the Construciton Script add a Create Mesh Section node
  5. Add a new Vector Array variable with 2 elements both set to 0.0 in the X, Y, and Z
  6. Add a new Integer Array variable with 3 elements set to 0, 1, and 2 respectively
  7. Compile the blueprint
  8. Add it to the level
  9. Select the Procedural Mesh Component in the details panel
  10. Select the Create Static Mesh button

RESULT:

The editor crashes

EXPECTED:

The editor doesn't crash and/or spits out an error in the output logs if this is an unintended workflow

Callstack
Error: === Critical error: ===
Error: 
Error: Assertion failed: !EdgeArray[EdgeID].ConnectedTriangles.Contains(TriangleID) [File:D:/Build/++UE4/Sync/Engine/Source/Runtime/MeshDescription/Private/MeshDescription.cpp] [Line: 907] 
Error: 
Error: 
Error: 
Error: [Callstack] 0x00007ffbfc763b19 KERNELBASE.dll!UnknownFunction []
Error: [Callstack] 0x00007ffb82a0d066 UE4Editor-Core.dll!ReportAssert() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Private\Windows\WindowsPlatformCrashContext.cpp:1616]
Error: [Callstack] 0x00007ffb82a107a8 UE4Editor-Core.dll!FWindowsErrorOutputDevice::Serialize() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Private\Windows\WindowsErrorOutputDevice.cpp:78]
Error: [Callstack] 0x00007ffb8271e8cd UE4Editor-Core.dll!FOutputDevice::LogfImpl() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Private\Misc\OutputDevice.cpp:61]
Error: [Callstack] 0x00007ffb826b5575 UE4Editor-Core.dll!AssertFailedImplV() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Private\Misc\AssertionMacros.cpp:104]
Error: [Callstack] 0x00007ffb826b7620 UE4Editor-Core.dll!FDebug::CheckVerifyFailedImpl() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Private\Misc\AssertionMacros.cpp:461]
Error: [Callstack] 0x00007ffbc7530da5 UE4Editor-MeshDescription.dll!FMeshDescription::ComputePolygonTriangulation() [D:\Build\++UE4\Sync\Engine\Source\Runtime\MeshDescription\Private\MeshDescription.cpp:907]
Error: [Callstack] 0x00007ffbc7533507 UE4Editor-MeshDescription.dll!FMeshDescription::CreatePolygon_Internal() [D:\Build\++UE4\Sync\Engine\Source\Runtime\MeshDescription\Private\MeshDescription.cpp:562]
Error: [Callstack] 0x00007ffbc7532ab7 UE4Editor-MeshDescription.dll!FMeshDescription::CreatePolygon() [D:\Build\++UE4\Sync\Engine\Source\Runtime\MeshDescription\Public\MeshDescription.h:537]
Error: [Callstack] 0x00007ffb721bb4da UE4Editor-ProceduralMeshComponent.dll!BuildMeshDescription() [D:\Build\++UE4\Sync\Engine\Plugins\Runtime\ProceduralMeshComponent\Source\ProceduralMeshComponent\Private\ProceduralMeshConversion.cpp:226]
Error: [Callstack] 0x00007ffb63f56b05 UE4Editor-ProceduralMeshComponentEditor.dll!FProceduralMeshComponentDetails::ClickedOnConvertToStaticMesh() [D:\Build\++UE4\Sync\Engine\Plugins\Runtime\ProceduralMeshComponent\Source\ProceduralMeshComponentEditor\Private\ProceduralMeshComponentDetails.cpp:118]
Error: [Callstack] 0x00007ffb63f581e7 UE4Editor-ProceduralMeshComponentEditor.dll!TBaseSPMethodDelegateInstance<0,FProceduralMeshComponentDetails,0,FReply __cdecl(void),FDefaultDelegateUserPolicy>::Execute() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:290]
Error: [Callstack] 0x00007ffb8d7d859e UE4Editor-Slate.dll!SButton::ExecuteOnClick() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:385]
Error: [Callstack] 0x00007ffb8d7f071e UE4Editor-Slate.dll!SButton::OnMouseButtonUp() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Widgets\Input\SButton.cpp:304]
Error: [Callstack] 0x00007ffb8d6346be UE4Editor-Slate.dll!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_cc5aea9e7377b04ce85c30c65ec3889b> >() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:378]
Error: [Callstack] 0x00007ffb8d6b7f14 UE4Editor-Slate.dll!FSlateApplication::RoutePointerUpEvent() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:4815]
Error: [Callstack] 0x00007ffb8d6a0337 UE4Editor-Slate.dll!FSlateApplication::ProcessMouseButtonUpEvent() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5356]
Error: [Callstack] 0x00007ffb8d693632 UE4Editor-Slate.dll!FSlateApplication::OnMouseUp() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp:5321]
Error: [Callstack] 0x00007ffbdd51bcb5 UE4Editor-ApplicationCore.dll!FWindowsApplication::ProcessDeferredMessage() [D:\Build\++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2178]
Error: [Callstack] 0x00007ffbdd509197 UE4Editor-ApplicationCore.dll!FWindowsApplication::DeferMessage() [D:\Build\++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:2642]
Error: [Callstack] 0x00007ffbdd51e389 UE4Editor-ApplicationCore.dll!FWindowsApplication::ProcessMessage() [D:\Build\++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:1046]
Error: [Callstack] 0x00007ffbdd504310 UE4Editor-ApplicationCore.dll!FWindowsApplication::AppWndProc() [D:\Build\++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsApplication.cpp:878]
Error: [Callstack] 0x00007ffbfcf35c1d USER32.dll!UnknownFunction []
Error: [Callstack] 0x00007ffbfcf35612 USER32.dll!UnknownFunction []
Error: [Callstack] 0x00007ffbdd51f914 UE4Editor-ApplicationCore.dll!FWindowsPlatformApplicationMisc::PumpMessages() [D:\Build\++UE4\Sync\Engine\Source\Runtime\ApplicationCore\Private\Windows\WindowsPlatformApplicationMisc.cpp:130]
Error: [Callstack] 0x00007ff68ba08848 UE4Editor.exe!FEngineLoop::Tick() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:4748]
Error: [Callstack] 0x00007ff68ba2117c UE4Editor.exe!GuardedMain() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:169]
Error: [Callstack] 0x00007ff68ba2125a UE4Editor.exe!GuardedMainWrapper() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:137]
Error: [Callstack] 0x00007ff68ba352bd UE4Editor.exe!WinMain() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:268]
Error: [Callstack] 0x00007ff68ba37fea UE4Editor.exe!__scrt_common_main_seh() [d:\agent\_work\5\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
Error: [Callstack] 0x00007ffbfd297c24 KERNEL32.DLL!UnknownFunction []
Error: [Callstack] 0x00007ffbfeb8d721 ntdll.dll!UnknownFunction []

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Fixed
Fix Commit16388007
Main Commit16388074
Release Commit16388007
CreatedMay 5, 2021
ResolvedMay 19, 2021
UpdatedJun 1, 2021