You can use the
vizmat.Distance command to calculate the distance between two points:
Code:
import viz
import vizmat
import vizact
viz.go()
avatar = viz.addAvatar('vcc_male2.cfg',pos=[0,0,5],euler=[180,0,0])
head = avatar.getBone('Bip01 Head')
def printDistance():
avatarPos = head.getPosition(viz.ABS_GLOBAL)
viewPos = viz.MainView.getPosition()
distance = vizmat.Distance(avatarPos,viewPos)
print distance
vizact.ontimer(1,printDistance)