I’m creating custom meshes (a table and a chair) by using the UProceduralMeshComponent class.
I defined a base class UBasicProcMesh that hinerits from UProceduralMeshComponent and stores vertices, indices, UVs and other stuff used for the geometry of a 3D object.
Then, I defined 2 subclasses of UBasicProcMesh, UTableProcMesh and UChairProcMesh, which store the specific geometry of a table and a chair respectively.
Finally, I defined 2 actors, ATable and AChair, which have an UTableProcMesh object and an UChairProcMesh object respectively.
Inside both actors, I removed the Tick() method and the bCanEverTick line and overriden BeginPlay(), PostActorCreated() and PostLoad().
These methods’s behaviours are pretty much the same for both actors (below, an example for the chair)
void AChair::BeginPlay()
{
Super::BeginPlay();
SetupMesh();
}
void AChair::PostActorCreated()
{
Super::PostActorCreated();
SetupMesh();
}
void AChair::PostLoad()
{
Super::PostLoad();
SetupMesh();
}
void AChair::SetupMesh()
{
Chair->DrawMesh("MeshChair");
Chair->SetWorldScale3D(ChairScale);
RootComponent->SetWorldLocation(SceneLocation);
}
...
void UChairProcMesh::DrawMesh(FString MeshType)
{
Vertices.Reset();
Triangles.Reset();
Normals.Reset();
Tangents.Reset();
UVs.Reset();
Colors.Reset();
DefineMesh(MeshType);
this->CreateMeshSection_LinearColor(0, Vertices, Triangles, Normals, UVs, Colors, Tangents, true);
}
If I place a table and/or a chair in the editor, everything is okay; if I place a table and use PIE, everything is okay; if I place a chair and use PIE, I get an exception.
If I use the Development Editor or the DebugGame Editor build I get
Fatal error!
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffff
0x00007ffa0b4f179c UE4Editor-CoreUObject.dll!StaticDuplicateObjectEx() [D:\Build\++UE4\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectGlobals.cpp:2111]
0x00007ffa0b4f086f UE4Editor-CoreUObject.dll!StaticDuplicateObject() [D:\Build\++UE4\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectGlobals.cpp:1961]
0x00007ffa04aa6ccc UE4Editor-UnrealEd.dll!UEditorEngine::CreatePIEWorldByDuplication() [D:\Build\++UE4\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:2098]
0x00007ffa06c6ae1f UE4Editor-Engine.dll!UGameInstance::InitializeForPlayInEditor() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Engine\Private\GameInstance.cpp:289]
0x00007ffa04aa4c5b UE4Editor-UnrealEd.dll!UEditorEngine::CreateInnerProcessPIEGameInstance() [D:\Build\++UE4\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:2652]
0x00007ffa04ac682c UE4Editor-UnrealEd.dll!UEditorEngine::OnLoginPIEComplete_Deferred() [D:\Build\++UE4\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:1474]
0x00007ffa04aa6899 UE4Editor-UnrealEd.dll!UEditorEngine::CreateNewPlayInEditorInstance() [D:\Build\++UE4\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:1708]
0x00007ffa04ae23da UE4Editor-UnrealEd.dll!UEditorEngine::StartPlayInEditorSession() [D:\Build\++UE4\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:2580]
0x00007ffa04ae569d UE4Editor-UnrealEd.dll!UEditorEngine::StartQueuedPlaySessionRequestImpl() [D:\Build\++UE4\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:1089]
0x00007ffa04ae5078 UE4Editor-UnrealEd.dll!UEditorEngine::StartQueuedPlaySessionRequest() [D:\Build\++UE4\Sync\Engine\Source\Editor\UnrealEd\Private\PlayLevel.cpp:1016]
0x00007ffa0456a854 UE4Editor-UnrealEd.dll!UEditorEngine::Tick() [D:\Build\++UE4\Sync\Engine\Source\Editor\UnrealEd\Private\EditorEngine.cpp:1611]
0x00007ffa04e437e6 UE4Editor-UnrealEd.dll!UUnrealEdEngine::Tick() [D:\Build\++UE4\Sync\Engine\Source\Editor\UnrealEd\Private\UnrealEdEngine.cpp:414]
0x00007ff64f447800 UE4Editor.exe!FEngineLoop::Tick() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:4850]
0x00007ff64f45ba7c UE4Editor.exe!GuardedMain() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:169]
0x00007ff64f45bb5a UE4Editor.exe!GuardedMainWrapper() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:137]
0x00007ff64f46e31d UE4Editor.exe!WinMain() [D:\Build\++UE4\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:268]
0x00007ff64f47145a UE4Editor.exe!__scrt_common_main_seh() [d:\agent\_work\5\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
0x00007ffa67867034 KERNEL32.DLL!UnknownFunction []
0x00007ffa67da2651 ntdll.dll!UnknownFunction []
If I use the DebugGame Editor build and open UE with Visual Studio debugger sometimes I get the same exception, sometimes everything works fine.
I tried to re-generate the Visual Studio files and re-compile but nothing changed.