When viewpoint collision is enabled a collision event will be generated when the viewpoint collides with an object. Information about the collision, including position, is available.
Code:
import viz
viz.go()
gallery = viz.add('gallery.ive')
viz.collision(viz.ON)
def onCollision(info):
print 'Collided at point',info.point
viz.callback(viz.COLLISION_EVENT, onCollision)