Once the chroma keying, background painting, additional animation is done, its time for compositing. Compositing means seamlessly integrating all the elements of each frame.

The above frame has more than 8 different layers. Each bogey of the train has been shot seperately against a blue screen. The size of the bogey is not as small in proportion to the cliff as it appears to be. The cliff has been shot separately, also the clouds, and the background. All this has been seamlessly integrated during compositing.