Prince of Egypt adds miraculous graphics to plot miracles

17 Jun 2002

The Academy of Motion Pictures Arts and Sciences likely won't give its Best Picture Oscar to an animated film, but Prince of Egypt personnel should be collecting plaques at the Scientific and Technical Academy Award ceremony in Los Angeles and maybe even a couple of Oscar statues.

As history tells it, hundreds of thousands of Jews escaped Egypt, followed by the Egyptian army. The portrayal of so many characters requires a technological miracle almost equivalent to the parting of the Red Sea.

DreamWorks, in conjunction with Silicon Graphics, developed a revolutionary exposure tool which facilitates the seamless integration of 2D and 3D elements in a scene. The exposure tool allows the production crew to set its stage with any combination of 3D elements and 2D paintings and then choreograph them as cameramen move through the scene.

During the chariot race, for example, the two princes and their horses are hand-drawn animation while the chariots are 3D props. The sequence combined 3D computer-generated elements such as the chariots, scaffolding, and sand with 2D elements such as the characters and their painted backgrounds.

The ten plagues were almost as hard on the animators as the were on the Egyptians, but if DreamWorks can create God (as a burning bush) they could create 7,000,000 locusts. The locusts, blood, hail, and even the Angel of Death were created using 3D particle systems which are linked like tiny dots in space. With the computer the animators could apply forces such as gravity or wind to move them around; once each particle's position was set in space it could be tendered to attain the desired look.

God need not worry too much about competition from DreamWorks. The parting of the Red Sea required 10 digital artists, 16 traditional animators, and two programmers. What lasted for seven minutes on the screen required more than 318,000 hours of rendering time - somewhat less than the 350,640 hours the Israelites spent wandering in the desert (based on exactly 40 years at 365 1/4 days a year). The filmmakers developed digital techniques to give the necessary level of detail to convey such a large-scale exodus.

In many cases traditional artwork was blended into digital animation; the water effects involving the Red Sea and the Nile included traditional animation, 3D effects, and 2D computer graphics.

Jewish history states that 600,000 Jews departed from Egypt, and many Jewish scholars believe that this figure only included adult males. In the final scene 146,000 fully animated characters are present - well beyond the capabilities of traditional animation.

The process began with hand-drawn design of a character which was then modeled into the computer in 3D. The initial character was reshaped to allow animators to produce four "key" characters representing extremes of height, weight, and age. The animators then took varying percentages of the four models and blended them in different proportions to create a data base of about 20 characters. Skin, hair color and clothing were then modified to provide additional variety. Then the process was duplicated to create women and children.

The characters were then given a "skeleton" so that the animators could assign repeatable motion cycles such as walking, hammering, polishing, or other functions. Applications of "behavioral software" made the computer-generated characters seem actually aware of their surroundings and the obstacles so that they didn't cross into each other's space. Since the computer was unaware that clothing fabric should not go through the skin and vice-versa, the clothing was animated along with the character.

Since the amount of data necessary to create so many 3D character models would have slowed down a computer to the point that hand-drawn animation would have been speedier, software developer Mike Ullner designed a crowd simulation program for scenes where the characters would only be seen from a limited perspective. The computer could map a two-dimensional image of an animated character onto a "card" in three-dimensional shape. Thus the computer, instead of needing thousands of data points for a 3D model, only needed the four data points of the "card" to show the character in motion from the audience's point of view.

Over 350 artists, animators and technicians from over 35 different countries spent four years to bring The Prince of Egypt to the screen.