A digital sleight of hand.

People are fascinated with special effects. The popularity of Terminator 2, Batman and this summer's Death Becomes Her confirms they are an important part of the entertainment industry, not only in film, but in television, games, music videos and commercials. Amazed by special effects, by all that appears to be, I find many teachers and students asking me, "How'd they do that?" It's not enough to be amazed by trickery and call it art; critical analysis and discussion of how these effects were achieved becomes a necessary part of aesthetic discussions.

Our students are watching this every day. They eat it up, they're fascinated by it, they think it's cool. Well, it is cool, but it can also be misleading. I think it's imperative to teach our students to discriminate between truth and slick fiction. They need to know how things can be manipulated so they don't become manipulated themselves. It was easier to detect the lies several years ago, but with the seamless adjustments technology has made possible today, how do we know?

The most recent questions I've gotten concern Michael Jackson's video Black and White, and the transformations in Terminator 2. If you've seen Black and White, you may recall that at the end of the video several faces appear on screen, one person becoming another. In Terminator 2, the T-1000 can change form, not only from person to person, but from inanimate objects like a floor or wall. Before discussing recent developments in special effects, it would be helpful to take a brief look backward.

Most of the special effects and transformations in the early days of the movie industry were done with make-up changes, mattes, stunt coordination and a series of dissolves. You may remember Spencer Tracy changing right before your eyes from Dr. Jekyll to Mr. Hyde. This was done with the assistance of a great make-up artist working on the actor. As the actor was transformed through make-up, he was filmed in sequence; then a series of dissolves from sequence to sequence captured the transition. As well as these scenes might have been constructed, the individual frames were detectable. Of course, through the shrieks and screams, no one really noticed, but you could see the individual changes.

Morphing

What happened in the Michael Jackson video, Terminator 2, and in the Exxon ad shown here, is called morphing. The morphing technique (or two-dimensional shape shifting) is first credited to Tom Brigham of New York Institute of Technology and first shown at SIGGRAPH in 1982. Interestingly, it wasn't until 1987 that Industrial Light and Magic used the effect for Ron Howard's film, Willow.

The term morphing is derived from the word metamorphosis, and specifies a two-dimensional process that manipulates a picture (usually a photograph). Morphing is done by stretching and altering parts of a picture in a frame buffer. (A frame buffer holds an image; each second of video represents thirty frames.) In a sense, this is what Peter Sorensen in Computer Graphics World has called a "digital sleight of hand."

Exxon Tiger

First, you need software that will allow you to stretch the pictures so the two images you wish to morph are in mid-alignment. Then you need the two original images (in the ad it was the tiger and the car) as closely aligned as possible. In the Exxon ad done by Pacific Data Images, four shots were used: * a motion control shot of the car driving by; * a matching motion control shot of the background without the car; * a motion control shot of the foreground over a blue screen; * a running tiger over the blue screen. (A motion control shot is computer controlled to ensure that the different frames are shot at the same speed and angle.)

The image of the car shrinks while the images of the tiger is pulled over the car. The software allows you to stretch the images like sheets of rubber; you push and pull the image with the mouse until you've pulled one image into the other. If you want the car to become a tiger, start by stretching the car. Notice the car is first "rippled" to anticipate the stripes of the tiger. Then the tiger is stretched, and a dissolve is used to have one image transform into the other. The live action must be handled with the care; trying to line up the images as tightly as possible is hard work, but the closer the shots are, the smoother the transition.

Terminator 2

The morphing in Terminator 2 was done by Lucas Arts Industrial Light and Magic (ILM). In Entertainment Weekly, Greff Kolday notes that ILM contributed forty-three key shots - just five minutes of screen time - but they required painstaking attention to detail, cost nearly $6.4 million, and used a monstrous 150 gigabytes of computer storage - nearly 4,000 times more computing power than most personal computers. Still, the techniques are simple enough.

Working with photographs, models and film, ILM built a three-dimensional model in the database which they could call up on screen and examine from every angle. Once the shape is defined mathematically, the computer can manipulate it. Technicians provide the computer with the first frame of the transformation and the final result; the computer mathematically figures out how to fill in the transition frames so that the first figure mutates fluidly into the last. This effect was first seen in Willow where different animals transformed into a witch.

Advertisements

Technique is already changing the way products are sold, and they may also be altering the way we experience reality. You may have recognized morphing used in commercials for Good Year Aquatread tires, Plymouth Voyager, and the latest, a Miller Lite commercial showing people evolving through the various trends of the 1960s through the 1990s.

While morphing is very popular right now, it is just one tool in a wide range of digital manipulations. For the recent Diet Coke commercials, Jimmy Cagney, Humphrey Bogart and Louis Armstrong are reanimated on screen, seamlessly blended into the commercial.

The idea of enhancement is certainly not new. For decades, models have been airbrushed for magazines and product packaging. What is new is that, with the enhancement and manipulation possible with computers, the model that appears on a magazine cover may not exist at all. In other words, the subject may have been so manipulated, enlarged shrunk, enhanced and touched up that the person we see is not a real person at all, but a composite image: eyes fixed, hair altered, cheek bones raised, lips made fuller, etc.

And so we are faced with an increasingly complex view of visual reality. It's an important issue to discuss, not only because we see this imagery every day, but because these techniques are within the reach of teachers and students. Gryphon Software Corporation sells a program called MORPH that allows the user to create the same kind of special effects seen in Terminator 2 and the Exxon ad, and it was selling for $89 at MACWORLD last summer. Kodak has begun to promote its new CD Photography that allows you to print your images to disk, and to manipulate them before printing.

Is "WOW" enough?

Despite all the new technology that elicits "wows" from audiences, it is clear that we must still start with the artistic decision. How can I best use this technology for my purposes? How does this assist the artist? Is the technology needed at all?

What should happen is that as equipment becomes more sophisticated, the viewer becomes more sophisticated as well. We must consider the resulting images. The images lie, and they always did. In the latest Diet Coke commercial, Paula Abdul is not dancing with Groucho Marx or Gene Kelly, but what if this were a compositing of lesser-known people, or of people who actually could be together, but were not. What are the consequences?

Just because something is technologically possible doesn't mean we have to do it. Yet, our students are watching this stuff every day and they like to think they're quite sophisticated about it. But are they?