def loadVisibleChunks(self):
        """ loads nearby chunks if the camera has moved beyond a certain distance """

        # print "loadVisibleChunks"
        if self.cameraMovedFarEnough():
            if datetime.now() - self.lastVisibleLoad > timedelta(0, 0.5):
                self.discardChunksOutsideViewDistance()
                self.loadNearbyChunks()

                self.oldPosition = self.position
                self.lastVisibleLoad = datetime.now()
 loads nearby chunks if the camera has moved beyond a certain distance 
renderer.py