###   TargetCamera for Nuke
###   
###   v1 - Last modified: 21/03/2009
###   Written by Olivier Lavenant & Lucien Fostier

import nuke

def TargetCamera():
  ## create the nodes
  scene = nuke.nodes.Scene ()
  set = nuke.nodes.Axis (name = "CameraAxis")
  target = nuke.nodes.Axis (name = "Target")
  cam = nuke.nodes.Camera (name = "Camera", selected = "false")

  ## Hook them up
  scene.setInput(0, cam)
  scene.setInput(1, target)
  #scene.setInput(2, target)
  #target.setInput(0, set)
  cam.setInput(0, set)

  ## Get the camera expression
  cam['rotate'].setExpression("-degrees(atan2 ((Camera.translate.y-Target.translate.y),sqrt(pow2(Camera.translate.z-Target.translate.z)+pow2(Camera.translate.x-Target.translate.x))))",0)
  cam['rotate'].setExpression("(Camera.translate.z-Target.translate.z)<=0?180-degrees(atan2 ((Camera.translate.x-Target.translate.x),abs(Camera.translate.z-Target.translate.z))):-degrees(atan2 ((Target.translate.x-Camera.translate.x),abs(Camera.translate.z-Target.translate.z)))",1)
  cam['rotate'].setExpression("curve",2)

  ## Target Position 
  target['translate'].setValue(15,2)