package require vtk package require vtkinteraction vtkXMesaRenderWindow renWin vtkMesaRenderer ren renWin AddRenderer ren vtkRenderWindowInteractor iren iren SetRenderWindow renWin vtkConeSource cone vtkMesaPolyDataMapper mp mp SetInputConnection [cone GetOutputPort] vtkMesaActor actor actor SetMapper mp ren AddActor actor renWin Render iren AddObserver UserEvent {wm deiconify .vtkInteract} iren Initialize # prevent the tk window from showing up then start the event loop wm withdraw .