If you import a static mesh with no setup lightmap and uncheck the option for Generate lightmap UV so that only the UV Channel 0 is present. When you use the Merge Actor tool with a single one of these actors or multiple of this actor with only a single UV the merged asset will save with no geometry leaving it corrupted.
There is a test asset attached and an image of the merged mesh from the static mesh editor.
1. Import a Static Mesh without a setup Lightmap UV (uncheck from the import option for generate lightmap UV)
2. Drag the actor into the world and make multiple if needed.
3. Open the Merge Actor tool and select these meshes.
4. Leave default settings and click Merge.
5. Open the merged Actor
6. Click on the UV, Normals, Tangents, or any button that is tied directly to the mesh from the toolbar.
Results: This is a corrupted mesh that is generated with no data.
MachineId:7D8A1A304BE9658328C158A3D14CC774
EpicAccountId:fb379e8f24784ff699eadd8655f07aef
Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 634]
Array index out of bounds: 0 from an array of size 0
UE4Editor_Core!FDebug::AssertFailed() [d:\builds\ue4_main\engine\source\runtime\core\private\misc\assertionmacros.cpp:332]
UE4Editor_Engine!DrawUVs() [d:\builds\ue4_main\engine\source\runtime\engine\private\primitivedrawingutils.cpp:1689]
UE4Editor_StaticMeshEditor!FStaticMeshEditorViewportClient::DrawUVsForMesh() [d:\builds\ue4_main\engine\source\editor\staticmesheditor\private\staticmesheditorviewportclient.cpp:837]
UE4Editor_StaticMeshEditor!FStaticMeshEditorViewportClient::DrawCanvas() [d:\builds\ue4_main\engine\source\editor\staticmesheditor\private\staticmesheditorviewportclient.cpp:825]
UE4Editor_UnrealEd!FEditorViewportClient::Draw() [d:\builds\ue4_main\engine\source\editor\unrealed\private\editorviewportclient.cpp:3361]
UE4Editor_Engine!FViewport::Draw() [d:\builds\ue4_main\engine\source\runtime\engine\private\unrealclient.cpp:1163]
UE4Editor_UnrealEd!UEditorEngine::UpdateSingleViewportClient() [d:\builds\ue4_main\engine\source\editor\unrealed\private\editorengine.cpp:1788]
UE4Editor_UnrealEd!UEditorEngine::Tick() [d:\builds\ue4_main\engine\source\editor\unrealed\private\editorengine.cpp:1564]
UE4Editor_UnrealEd!UUnrealEdEngine::Tick() [d:\builds\ue4_main\engine\source\editor\unrealed\private\unrealedengine.cpp:371]
UE4Editor!FEngineLoop::Tick() [d:\builds\ue4_main\engine\source\runtime\launch\private\launchengineloop.cpp:2855]
UE4Editor!GuardedMain() [d:\builds\ue4_main\engine\source\runtime\launch\private\launch.cpp:152]
UE4Editor!GuardedMainWrapper() [d:\builds\ue4_main\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() [d:\builds\ue4_main\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
Head over to the existing Questions & Answers thread and let us know what's up.
1 |
Component | UE - Gameplay |
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Affects Versions | 4.13, 4.14, 4.15 |
Target Fix | 4.15 |
Fix Commit | 3198141 |
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Main Commit | 3198987 |
Created | Nov 11, 2016 |
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Resolved | Nov 15, 2016 |
Updated | Apr 27, 2018 |