import Blender
from Blender import *

def cercleBezier(rayon):
	h = 0.552 * rayon
	p = 1.0 * rayon
	p1 = [-p,-h,0.0,-p,0.0,0.0,-p,h,0.0]
	p2 = [-h,p,0.0,0.0,p,0.0,h,p,0.0]
	p3 = [p,h,0.0,p,0.0,0.0,p,-h,0.0]
	p4 = [h,-p,0.0,0.0,-p,0.0,-h,-p,0.0]
	cur = Curve.New('CercleBezier')
	cur.appendNurb(BezTriple.New(p1))
	cur[0].append(BezTriple.New(p2))
	cur[0].append(BezTriple.New(p3))
	cur[0].append(BezTriple.New(p4))
	cur[0].setFlagU(1)
	cur.setFlag(25)
	cur.setPathLen(250)
	return cur

scn = Scene.GetCurrent()
ob = scn.objects.active
cercle = scn.objects.new(cercleBezier(5.0))
cercle.setLocation(ob.loc)
cam = scn.objects.camera
cercle.makeParent([cam], 1)
cc = cam.constraints
cs = Constraint.Settings
cc.append(Constraint.Type.TRACKTO)
cc[0][cs.TARGET] = ob
cc[0][cs.TRACK] = 5
cc[0][cs.UP] = 1

Blender.Redraw()
#scn.play()