[vtkusers] how vtkpointpicker->getpickposition works

[kshivann at engineering.uiowa.edu]

hi,
  i am using vtkpointpicker->getpickposition. some how the values that i get 
are not correct. does anyone know how does vtkpointpicker->getpickposition 
works. And also is there a way to disable rotations from mouse interaction.

thanks

kiran