MOVIES : Bytes ... Camera ... Action! : No longer used just for morphing and monsters, digital technology is becoming as much a part of movie-making as lights and actors. Moonwalk, anyone?

In Hollywood, the future has arrived, and it is digital.

Lights, cameras and action aren’t quite things of the past, but in many of this summer’s biggest films, movie magic has been created instead with hard drives and state-of-the-art software.

When summer audiences watch Tom Hanks taking a glitch-plagued trip to the moon in “Apollo 13,” Denzel Washington battling a cyber-villain in “Virtuosity” Ben Kingsley taking on an alien terror in “Species” or even “Casper” the famously friendly ghost attempting to bond with flesh-and-blood humans, they will be witnessing the results of some mind-boggling advances in computer technology.

And with theater screens also offering such varied summer entertainments as “Die Hard With a Vengeance,” “Batman Forever,” “Congo,” “Judge Dredd” and “Waterworld,” most moviegoers will soon experience the virtual reality of digital filmmaking.

“The tools of digital filmmaking are now so accessible and so powerful that it’s almost impossible not to use them,” says “Virtuosity” director Brett Leonard. “Even if you’re just telling a simple story about two people in a room.”

Or perhaps three men in a can. In Ron Howard’s “Apollo 13,” which opens Friday, spectacular, cutting-edge computer work allows Hanks, Kevin Bacon and Bill Paxton to take a chill-inducing trip to the moon. Almost every detail of spaceflight in the film--from the roaring flames during liftoff to the heated glow on the astronauts’ face shields during re-entry--is the product of digital artistry that allowed for previously unattainable realism.

The computers also allowed for some unprecedented--and dizzying--perspectives. The film contains overhead close-ups of the rocket’s liftoff, thruster’s-eye views of booster rockets being disengaged and phenomenal looks into and out of the rocket’s windows.

Computers are allowing digitally savvy producers, directors and special-effects artists to rewrite the rules of movie-making almost daily. Images that were once too costly, too dangerous or simply too phantasmic to bring to the screen the old-fashioned way have become part of a day’s work for the computer whizzes at effects companies such as Digital Domain, Boss Film Studios and Industrial Light & Magic.

And while the computer tools developed at these virtual studios can fill a film with eye-grabbing special-effects creations such as the dinosaurs of “Jurassic Park,” the ghosts of “Casper” or the malfunctions of “Apollo 13,” they also allow a director to craft the smallest details of a film frame by frame.

A sequence shot at high noon can be run through the computer and set at dusk. A perfectly romantic digital moon can be hung over a love scene if the real moon wasn’t quite lovely enough the night the scene was filmed. Entire sets and backgrounds can be augmented, corrected or created whole by digital artists.

In “Apollo 13” computer artists re-created the events of the ill-fated launch in nail-biting detail. Their artistry is evident in the spectacular liftoff sequence, but there was subtler work as well. Computers were also used to add the shifting reflection of sunlight on the disabled command module and to create the deep shadows of the lunar surface. There was even call for some non-rocket-related computer work--like creating a perfectly arched contrail for a Cape Kennedy-bound jet. All of this work mixes so seamlessly with the performances that what might once have been considered a “special-effects” film is now one in which the effects are as believable as the real-life story they support.

“The digital filmmaking tools are becoming the regular filmmaking tools,” says Leonard, who introduced a broad audience to the concept of virtual reality with “The Lawnmower Man” (1992) and who recently formed his own virtual studio, L2 Communications.

“I actually hate the term special effects because it implies that it’s something outside of the regular filmmaking process--it’s special . Well, a dolly shot used to be a special effect. Sound used to be a special effect. They started out as gimmicks and ended up changing how films were made. For the coming generation of filmmakers, digital tools aren’t just for big special effects--they’re going to become as standard as cameras, dollies and microphones.”

Rather than seeing this change as a threat, many of the talents who have made careers creating effects without computers are embracing their arrival.

Richard Edlund, the founder of Boss Film Studios, has overseen the Oscar-winning visual effects on such films as “Star Wars,” “The Empire Strikes Back,” “Return of the Jedi” and “Raiders of the Lost Ark.” The effects in those films were accomplished photochemically--through painstaking work with models, motion-control cameras and optical printers. But now the optical printers lie dormant at the Boss studios in Marina del Rey, while increasingly fantastic visions are brought to life by way of immensely powerful computer equipment.

“We are inhabiting the digital world with a great deal of glee,” Edlund says. “It always felt like an arm wrestle, or even a sumo wrestle, to get what you wanted with the old chemical-optical approach to effects. The digital approach is much more elegant and intellectual. There are a lot of challenges for us to meet, but I have a feeling we’re going to be knocking them down like bowling pins.”

Edlund has taken on one of the major digital challenges in “Species”--that of digital performance. The film co-stars Ben Kingsley and a rampant alien named Sil, and though Sil will appear to be a frighteningly real piece of extraterrestrial biology, she in fact was almost entirely computer-generated, with each frame of her existence made possible by roughly 10 times the amount of digital information that it took to bring a “Jurassic Park” dinosaur to life.

From a producer’s point of view, digital technology is reshaping not only the mechanics of filmmaking but the aesthetics and economics as well.

“In some ways we’ve already explored the boundaries of how big movies can get using conventional means,” says producer Frank Mancuso Jr., who has just taken the plunge into the digital world with “Species.” “Money that would have been burned building bigger sets or sound stages is now going to flow in this other direction. I think it began with ‘Terminator 2,’ which really marked the arrival of the digital future. When that movie came out, it stopped me in my tracks, because it showed me things I just couldn’t have seen before. I think that’s going to happen at the movies with increasing frequency.”

‘The handcuffs are off,” says director James Cameron. “If you can imagine it and visualize it, you can make it happen.”

Cameron became one of the first filmmakers to embrace digital technology, with the watery pseudo-pod in “The Abyss” (1989) and the deadly molten-metal man of “Terminator 2” (1991). For years Cameron toyed with, but shied away from, the idea of starting his own computer-effects company.

But when he crossed paths with Oscar-winning creature-effects creator Stan Winston (“Predator,” “Aliens,” “Jurassic Park”) and Scott Ross, the former chief at George Lucas’ Industrial Light & Magic, Cameron realized that he had found kindred digital spirits. In February, 1993, after much deep discussion, and with financing from IBM, the three plunged into the digital world headlong and founded the Venice-based Digital Domain.

The explosive action of Cameron’s “True Lies” and the moody neck-biting of Neil Jordan’s “Interview With the Vampire,” both released last year, were largely the products of Digital Domain’s busy Silicon Graphics workstations. Those computers allowed Arnold Schwarzenegger to fly a Harrier jet through Miami’s business district, and they turned Tom Cruise into a delicately veined vampire whose wounds could heal on cue.

Most recently, the computers were put to use to bring to life the ill-fated moon launch that is the subject of “Apollo 13.”

Digital Domain’s offices, computer stations and staging areas fill the former headquarters of the Chiat/Day advertising firm--environs that are at once high-tech, homely and hip. In the building where the hard-core computing takes place, the ghostly glow of terminals provides the only light, and there is a steady hum of hard drives and hushed conversations. Next door, in an airy, warehouse-size space, the Frank Gehry-designed main conference room has the appearance of a capsized ark, and a multitude of work cubicles have been roughly fashioned from recycled lumber.

With the success of “True Lies” and “Vampire” behind him--and “Apollo 13” about to hit theaters--Ross, Digital Domain’s chief executive officer, believes that the virtual filmmaking process is just beginning to work: “We hired a lot of people from disparate skill sets--people from the film industry, computer science people, people from video post-production, photo retouching and traditional artists. We had to, because the kind of artistic digital specialists the technology requires don’t really exist yet. We’re all learning as we go. With that mix of creativity and technology in a brand-new company, we’ve got a studio that functions, but it is at best difficult. We’re basically asking a lot of people to learn Esperanto and write poetry at the same time. It makes for a more creative environment, but at times it’s frustrating.”

Cameron believes that the moments of frustration are beginning to give way to more and more moments of satisfaction.

“I think this technology is allowing filmmaking to become more artistic,” he says. “It’s more like you’re actually painting a movie, rather than trying to get everything to happen in that window of time and space in front of the camera lens. It’s been 20 or 30 years that we’ve been manipulating movie sound in a sound mix after the fact.

“Now the line between filming and editing is getting blurred. We can not only edit from image to image, but we can edit within the image--taking things out or putting things in to improve the flow or tell the story better or even cover mistakes. It’s still very hard work, but it’s amazingly satisfying work.”

What makes the digital-effects process special is that the laws of time and physics are suspended while a film sequence is being worked on. Once a filmed image is entered into the computer, that shot can be tweaked and toyed with endlessly until a seamless blend of live-action and digitally generated imagery is achieved. Only after the sequence is perfected on the computer screen is it transformed back into film.

That means that a director can now create sequences that would have been impossible to get in front of the camera in real time.

When Cruise as the vampire Lestat was engulfed in flames in “Interview With the Vampire,” the audience was seeing a real Cruise, and real flames. But Cruise was filmed reacting as if he were on fire, and the flames were added in the computer. The result is a realism that could not have been attained with stunt doubles or the traditional “flame suit.”

The time spent meticulously creating such computer effects can sometimes take an odd toll on their creators.

“After working on ‘Vampire’ for a year and watching blood and burns and wounds on my computer screen, I developed a strange appreciation for them,” says Digital Domain digital artist Adam Stark. “I’d be walking down the street and find myself thinking, ‘I wonder how fire would look on that guy’s face?’ ”

“Interview” also marked a breakthrough usage of the “digital back lot.” When shots required huge stretches of New Orleans waterfront or vistas of moonlit sea, they were constructed wholly in the computers. A rooftop view of Paris was actually a digital matte painting, deceptively animated with roaming dogs, people moving in apartment windows and a crackling bonfire--all of which had been filmed in studio and then inserted into the sequence digitally.

Such digital artistry is now being relied on to create a smooth blend of images that are both spectacular and mundane. When Tom Hanks, Kevin Bacon and Bill Paxton head for the moon in “Apollo 13,” they will be rocketing through computer-generated heavens and drifting above lunar landscapes created at Digital Domain. But computers are also responsible for every speck of dust and ice that falls from the rocket at liftoff. And, when director Howard decided that one scene had been filmed under a sky that was too clear, Digital Domain added the appropriately wispy clouds he desired.

In pre-production meetings, Howard considered the possibility of using NASA file footage. But after he and Digital Domain’s Ross reviewed some of that footage, they realized that the memories of images of televised liftoffs were more powerful than the images actually captured on 16-millimeter film at the time. So part of Digital Domain’s challenge became to create rocket sequences that were true to the viewers’ collective memory of the events.

“Our stuff had to look better than the old footage,” Ross says. “But if it looked too good you’d lose the feel of the story. I knew we were on the right track when our crew started having a hard time telling the difference between NASA’s still photos and photos of our work.”

No aspect of spaceflight was too large for the computers to take on. The gigantic launch pad and flight control center were filmed as scale models and then digitally integrated with location footage. No image was too small--or too gross, either--for the digital artists. Unafraid to get their hands dirty, they spent many hours creating one of the film’s most striking images--the ejection of space-bound urine crystals from the side of the command module.

At George Lucas’ Industrial Light & Magic, pioneering computer work allowed Forrest Gump to stumble his way through film footage of historical figures and turned Jim Carrey into a human cartoon for “The Mask.” For “Casper,” visual-effects teams there were concerned with expanding the performance abilities of wholly digital characters at the same time they further explored the use of a digital back lot.

So, while even computer illiterate filmgoers might spot ILM’s impressive handiwork in creating “Casper’s” ghosts, they probably will not be able to tell that in several scenes the formidable house the ghosts are haunting is also an entirely digital construction.

ILM visual-effects supervisor Dennis Muren has been a part of many of the company’s biggest films, including “Jurassic Park,” “Terminator 2” and the “Star Wars” trilogy, and in the process has racked up eight Academy Awards for best achievement in visual effects. He says that exploring the digital back lot has become a priority for company founder Lucas: “He really wanted us to get in there on ‘Casper,’ so instead of something like the ‘Psycho’ house on the hill getting built on a real back lot, we built the ‘Casper’ house on the hill inside the computer, and we hope it fools the audience.”

“That’s the art of it right now,” says Fred Raimondi, a visual-effects supervisor at Digital Domain. “We spend a lot of time on the computer trying to create images that look like they had nothing to do with a computer.”

The power of computers has not diminished the importance of human skills.

“You don’t say, ‘I want this to morph into that’ and hit ‘Enter,’ ” Jon Bruno says with a laugh. Bruno, a director and visual-effects supervisor at Digital Domain, has worked with Cameron since they collaborated to create a seminal digital-effects moment with the attention-grabbing “water tentacle” from “The Abyss.”

“There’s no button that puts Arnold in a jet or that turns Tom into a burning vampire or that sends your astronauts to the moon,” he says. “There’s still a lot of artistry and filmmaking experience that goes into these effects.”

ILM’s Muren says that as computer technology becomes more powerful, the job of creating a convincing digital reality can actually become more difficult for filmmakers.

“Our abilities are catching up with the technology,” he says. “We got into ‘Casper’ thinking that it was going to be really, really difficult to make these ghosts work, and as we got into it, we realized we’d underestimated exactly how difficult it was going to be. ‘Jurassic Park’ had about 60 digital shots total. For ‘Casper’ we had up to 45 shots going at the same time. We were doing almost all the work of ‘Jurassic Park’ for one scene of ‘Casper.’ ”

Curiously, one of the highest achievements to which digital filmmakers can aspire is to have their work go completely unnoticed.

“We’re not striving for people to say, ‘That’s the coolest computer graphic I’ve ever seen,’ ” says “Casper” animation director Eric Armstrong. “We want them to watch the movie and be engrossed in the story and not worry whether a character is flesh and blood or graphically rendered.”

Rob Legato, a Digital Domain visual-effects supervisor, says his ego is sturdy enough to handle the lack of credit that invisible artistry may entail.

“For the first time we can do a lot of things in film where you don’t see the trick,” he says, “and that can lead to some backhanded compliments like ‘I didn’t notice your work.’ The effect isn’t as impressive as if it jumped out on its own, but the fact that we can cut our work into a sequence without having an audience know it’s being tricked is actually a bigger compliment.”

Digital Domain’s Ross says that invisible effects are the standard that digital filmmakers are going to have to meet each time out: “There are seamless effects, and there are ‘How did they do that?’ effects. But even on the ‘How did they do that?’ effects, you only want that question to occur to people the second time they see a movie. The first time, they should be screaming at the Terminator or cringing from Lestat or gasping for oxygen with the astronauts of Apollo 13.”

Despite the gleaming new technologies and wild possibilities of the digital world, some basic truths of filmmaking remain unchanged. For all the computer work showing up on movie screens, the audience is still full of non-digital human beings who are looking for well-told stories.

“My tool set as a director is now bigger than it’s ever been,” Cameron says. “But no matter how deeply enmeshed you become in the technical and logistical aspects of filmmaking, you have to acknowledge the human component in film--because that’s what the audience cares about. And that’s what I care about when I go to the movies. I think I react the way audiences are meant to react. I get an emotional buzz. I still cry at movies.”