vtkBillboardTextActor3D's transformation is ignored when in a vtkAssembly
When creating a vtkBillboardTextActor3D as such:
vtkBillboardTextActor3D* textActor = vtkBillboardTextActor3D::New();
textActor->SetInput("testaaarossslaaa");
textActor->SetPosition(6.0, 6.0, 6.0);
textActor->GetTextProperty()->SetFontSize(12);
textActor->GetTextProperty()->SetColor(1.0, 1.0, .4);
textActor->GetTextProperty()->SetJustificationToCentered();
And adding it to a vtkAssembly as such
vtkAssembly* assembly = vtkAssembly::New();
assembly->AddPart(textActor);
renderer->AddActor(assembly)
The vtkBillboardTextActor3D will always be shown at the origin whereas if we add it directly to the vtkRenderer, it will properly show up at {6.0, 6.0, 6.0}
renderer->AddActor(textActor)