Can you post some example code that does not work for you?
The following uses
vizact.easeIn to start the spin slowly:
Code:
import viz
import vizact
viz.go()
gallery = viz.addChild('gallery.ive')
ball = viz.addChild('ball.wrl',pos=[0,1.8,3])
spin = vizact.spinTo(euler=[180,0,0],speed=45,interpolate=vizact.easeIn)
vizact.onkeydown(' ',ball.addAction,spin)