Why changing example to port it to VR doesn't work?

VR/AR
4

I created a simple code to reproduce this problem, and still, it doesn’t show anything:

#include <vtkActor.h>
#include <vtkConeSource.h>
#include <vtkNew.h>
#include <vtkOpenVRCamera.h>
#include <vtkOpenVRInteractorStyle.h>
#include <vtkOpenVRRenderer.h>
#include <vtkOpenVRRenderWindow.h>
#include <vtkOpenVRRenderWindowInteractor.h>
#include <vtkPolyDataMapper.h>

int main(int argc, char* argv[])
{
  // Setup the OpenVR rendering classes
  vtkNew<vtkActor> actor;
  vtkNew<vtkOpenVRRenderer> renderer;
  vtkNew<vtkOpenVRRenderWindow> renderWindow;
  vtkNew<vtkOpenVRRenderWindowInteractor> iren;
  vtkNew<vtkOpenVRInteractorStyle> style;
  vtkNew<vtkOpenVRCamera> cam;

  renderWindow->AddRenderer( renderer.Get() );
  renderer->AddActor( actor.Get() );
  iren->SetRenderWindow( renderWindow.Get() );
  iren->SetInteractorStyle( style.Get() );
  renderer->SetActiveCamera( cam.Get() );

  // Without the next line volume rendering in VR does not work
  renderWindow->SetMultiSamples( 0 );

  // Add a cone to the scene
  vtkNew<vtkConeSource> cone;
  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputConnection( cone->GetOutputPort() );
  actor->SetMapper( mapper.Get() );

  // Render
  renderer->ResetCamera();
  renderWindow->Render();
  iren->Start();

  return EXIT_SUCCESS;
}