For others who might have this question, the Viz3 way to find out if
an object has stopped moving (goto or spinto) is:
Code:
import viz
viz.go()
ground = viz.add('tut_ground.wrl')
ground.addAction(vizact.spinto(0,1,0,90,90))
def FinishedMoving(e):
if e.object == ground:
print 'done'
viz.callback(viz.ACTION_END_EVENT,FinishedMoving)