FBX Import into Level node rotation

User has pointed out that generating FBX files through C++ causes the level nodes and a light node.

I'm not fully versed with this, so the notes from the user may be more helpful for their description of the issue.

" When importing a fbx map will lights and some nodes that doesn't have attribute, I found out that a node that doesn't have an attribute, gets rotated around 90° yaw if the node before it was a light.

I had to debug the engine and found out that the potential issue is in the file "Engine\Source\Editor\UnrealEd\Private\Fbx\FbxMainImport.cpp" in functionFFbxImporter::TraverseHierarchyNodeRecursively. The issue is that ChildInfo.AttributeUniqueId is not initialized, causing it to get a value that was previously on the stack if the node doesn't have an attribute. For UE developers, the fix is to simply add ChildInfo.AttributeUniqueId = ChildInfo.UniqueId when the node doesn't have an attribute."

The workaround for this, provided by the user, is to make sure that a node with an FBXNull attribute is used.

1. Open UE4
2. Go to File > Import into Level
3. Import the attached FBX
4. Open the Blueprint and look at the nodes rotation

Regression: No

Results: Level nodes are rotated 90 degrees

Expected: Level nodes should not be rotated 90 degrees

FBX Import Level node rotation bug under rare circumstances