LIGHT CAMERA MAGIC

You can slice him, dice him, slash him, and mash him, but each time T-1000, the liquid-metal cyborg that oozes his way through Terminator 2, comes back for more. In a movie already packed with special-effects breakthroughs, the protean T-1000-a seamless blend of makeup, life-size puppets, computer graphics, and Robert Patrick's acting-is a technical tour de force unlike anything the movies have ever seen. ''A lot of what we did you can do at home on a Macintosh,'' says Dennis Muren, who supervised T2's team of 35 computer-graphics artists at George Lucas' renowned special-effects shop, LucasArts Industrial Light & Magic. ''But you can't do it in the time, or with the resolution and precision, that this show required.'' That's a major ''but.'' The 43 key shots that ILM contributed to the film amounted to 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 a 40-megabyte home computer. Still, the techniques employed in the creation of T-1000 are simple enough. Working from photographs, models, and films of Patrick going through T-1000's moves, the ILM team first built a three-dimensional model of T-1000 in their data base, which they could then call up on their screens and examine from any angle. In fact, since one of T-1000's tricks involves changing from a free- flowing metal blob into a fully detailed human shape, the team built four models, ranging from stage one, an amorphous metal shape, to stage four, a complete metallic man. For the scenes in which T-1000 mutates from one form to another-when he pours himself into a helicopter and then takes on a human shape, for example-ILM used a process called ''morphing'' (for ''metamorphosis''). To create a morphing sequence, ILM technicians provide a computer with the first frame in the transformation and the final result; the computer mathematically figures out how to fill in the transitional frames so that the first figure mutates fluidly into the last. Moviegoers saw their first example of morphing in Willow (different animals transform into Raziel the witch). But the process has never been applied more extensively than in T2. Once the ILM technicians put T-1000 through its scripted moves, they used a process called ''digital compositing'' to combine the figure with background scenes that had been filmed and then converted to digital computer memory. Both the backgrounds and the animated figures are read by the computer as a grid of individual points of light, or pixels. Since the artists can manipulate the pixels at will, they are able to remove imperfections or add shadows and reflections for greater realism. Traditional special-effects photography requires filming individual elements on top of one another, often revealing telltale matte lines and gradations in film quality where the separate elements meet; the computer-generated scene appears seamless. Once the work is completed, the finished sequence is electronically transferred back onto film, one frame at a time. If the computer-generated T-1000 were operating in a completely computer- generated world-characterized by the hard edges and uniform colors that pop up in TV commercials-that would have been the end of the job. But in order to blend convincingly into live-action sequences, ''this stuff had to look photo- realistic,'' says Muren. ''This is nothing like a (computer-graphic)world. This had to have its own reality.'' For example, in the shot in which T-1000 strides out of a flaming truck wreck in a flood canal, ILM's artists were able to combine the computer- originated figure with actual footage of the canal to make an utterly convincing whole. Cameron thinks the end result is T2's best FX sequence. ''It's the most complex, sophisticated shot in the film,'' he says. ''It's full-body, human-motion animation. That had never been done before. There had been simulations of it, but there had been something always slightly wrong. It would look like Michael Jackson doing the moonwalk.'' Contrary to some accounts, however, not all the eye-boggling effects in T2 came from computer animation. The special-effects house Fantasy II used models, life-size props, and stop-motion photography in several scenes, including the futuristic war sequence that opens the film. And the stunning nuclear-attack nightmare was re-created with the help of highly detailed miniature sets by 4-Ward Productions. Many of T-1000's most dramatic moments were also the product of more traditional techniques. Visual-effects master Stan Winston provided makeup, body prostheses, and misshapen puppets to bring T-1000 fully to life. Each of his creations detailing T-1000's successive breakdowns even acquired its own nickname: Splash Head (when the cyborg's head splits nearly in two), Donut Head (showing him with a gaping hole in his noggin), and Pretzel Man (as he breaks up into sections just before his fall into the fiery pit). Meshing ILM's work with Winston's was crucial to achieving the illusions. In most of the scenes where T-1000 is shot or otherwise sundered, the first part of the effect involved one of Winston's devices, which was worn by Patrick and rigged with radio- or cable-controlled triggers to fire on cue; when it came time for T-1000 to pull himself together, the ILM team then stepped in to provide the shots in which T-1000's wounds heal themselves. To fake bullet holes in the creature's chest, Winston invented spring-loaded foam-rubber devices made to look like molten metal. Working from his designs, ILM used its own homemade computer programs to reverse the process, healing the ''wounds'' entirely by computer. Coproducer B.J. Rack, who oversaw the massive special- effects effort, sums up the significance of this and the dozens of other technical miracles in the summer's most visually dazzling movie. ''There's a kind of magic between the few seconds that are physically real, because they involve real objects, and the computer graphics, which, though awesome, are not physically present,'' she says. ''In your mind, it all smears together so that you'd swear it was all real.''