First, Colpron drew a storyboard, based on the writers' script and the director's guidelines. The storyboard, a pencil drawing on paper, breaks down a camera shot into its most basic angles and elements. When the scene is shot, the storyboard is used to guide the cinematographer's lighting and camera angles.

The actors are filmed moving, talking and interacting against a blue screen. Various points on the blue act as markers or reference points for the animation created later at BBFXA's studio during postproduction, when the blue screen will be removed digitally and replaced by the Dark City.

Rachiele explains: "Transferring moving and talking actors into a virtual environment is difficult. The technique is called motion tracking and it's a specialty we have been perfecting, even creating our own software, since 1993. By using mathematical triangulation we line up the reference points on the blue screen to the virtual camera in our computer and reproduce the movement, speed and focal length of the action camera. Motion tracking is time consuming but the results are visually stunning."

Next, the scene undergoes a final digital process. This stage is called compositing. A powerful computer using sophisticated software blends together all the layers of elements including the foreground, middle and background of the Dark City as well as the sky, the moving actors and moving camera.

"The glue that holds the layers together is light," explains Rachiele. "On the computer, the artist can work with various layers shot under different light conditions and seamlessly integrate them into an organic an uniform image."

Another stunning CGI effect used in The Neverending Story is morphing. One of the characters in Fantasia is Gmork, a shape-shifter who transforms from wolf to man. He is able to leap from Fantasia via the Neverending Book that Bastian reads into the real world. And the audience sees his transformation. In the old days of movie making, the camera would have panned to a full moon!