This image was generated with the following code:

from direct.directbase.DirectStart import *
from pandac.PandaModules import *
from direct.actor.Actor import Actor
import random

# Turn off the default DisplayRegion
base.camNode.getDisplayRegion(0).setActive(False)

env = loader.loadModel('environment.egg')
env.reparentTo(render)

# Make four new DisplayRegions, in a quad.
for coords in [(0, 0.5, 0, 0.5), (0.5, 1, 0, 0.5),
               (0, 0.5, 0.5, 1), (0.5, 1, 0.5, 1)]:
    dr = base.win.makeDisplayRegion(*coords)

    cam = camera.attachNewNode(Camera('cam'))
    dr.setCamera(cam)

    cam.setPos(random.uniform(-300, 300),
               random.uniform(-300, 300),
               random.uniform(20, 60))
    cam.setHpr(random.uniform(0, 360), 0, 0)