You could try using a
viztracker.MouseTracker. Here's a simple example:
Code:
import viz
import viztracker
import vizact
viz.go()
gallery = viz.addChild('gallery.osgb')
ball = viz.addChild('soccerball.osgb')
#Move the object with mouse movements and mousewheel
mousetracker = viztracker.MouseTracker()
link = viz.link(mousetracker,ball)
#Disable the link and place the object with a mousepress
vizact.onmousedown(viz.MOUSEBUTTON_LEFT, link.disable)
viz.mouse(viz.OFF)