If you're using the viztracker method you can move the position of the user with the movable node. See the
using viztracker page for more information.
Or you can link the viewpoint to the tracker and set the link mask to orientation. That will allow you to move the viewpoint position:
Code:
isense = viz.add('intersense.dle')
oriTracker = isense.addTracker()
viz.link(oriTracker,viz.MainView, mask = viz.LINK_ORI)
viz.MainView.setPosition([0,1.5,1])