blender-lookat.py

import bpy
import math
import re
from collections import namedtuple

def lookat(location, camera):

  xIn = camera.location.x - location.x
  yIn = camera.location.y - location.y
  zIn = camera.location.z - location.z

  x = math.pi / 2
  y = 0
  z = 0

  try:
    z = math.atan(yIn/xIn)
  except ZeroDivisionError:
    print('div error')
    z = 0

  if xIn >= 0:
    z += math.pi / 2
  else:
    z -= math.pi / 2

  try:
    x = math.atan(math.sqrt(yIn * yIn + xIn * xIn) / zIn)
  except ZeroDivisionError:
    print('div error 2')
    x = 0

  if zIn < 0:
    x += math.pi
  elif zIn == 0:
    x += math.pi / 2

  camera.rotation_euler = (x, y, z)


def save(name):
  bpy.context.scene.render.image_settings.file_format='PNG'
  bpy.context.scene.render.filepath = 'out/' + name
  bpy.ops.render.render(write_still=True)

def deselectAll():
  for obj in bpy.data.objects:
    obj.select_set(False)

def printObjects():
  for obj in bpy.data.objects:
    print(obj.name)

def map(value, sourceMin, sourceMax, outMin, outMax):
  source = sourceMax - sourceMin
  out = outMax - outMin
  return outMin + ((value - sourceMin) / source) * out

def getCameras():
  cameras = []
  for obj in bpy.data.objects:
    if (re.match("Camera", obj.name)):
      # print(obj.name)
      cameras.append(obj)
  return cameras

Vector = namedtuple('Vector', ['x', 'y', 'z'])

deselectAll()
bpy.data.objects['Camera'].select_set(True)
# bpy.data.objects['Cube'].select_set(True)
bpy.ops.object.delete()

rings = 10
segments = 24
radius = 20
for j in range(rings):
  a = map(j, 0, rings, 0, math.pi)
  r = radius * math.sin(a)
  z = map(j, 0, rings, -radius, radius)
  for i in range(segments):
    aXY = map(i, 0, segments, 0, math.pi * 2)
    x = r * math.cos(aXY)
    y = r * math.sin(aXY)
    bpy.ops.object.camera_add(location=(x, y, z))

cameras = getCameras()
for cam in cameras:
  # print(cam)
  lookat(Vector(0, 0, 0), cam)

i = 0
for cam in cameras:
  bpy.context.scene.camera = cam
  save('out/lookat-' + str(i))
  i += 1