Never mind all the Hollywood hype about computer-driven effects being the star of the summer movie season. What’s driving much of the gee-whiz stuff is strictly low-tech as well as being one of the oldest tricks in show business.

It’s all in the movie models.

A corps of some 300 tinkerers making $25 an hour in sweltering, nondescript L.A. warehouses and armed with little more than glue guns are key to today’s digital glitz.

Just a few years ago, many of these artisans were convinced that they would be rendered obsolete by computer advances.

Larry DeUnger, a model maker at BOSS Films Studios, acknowledges that he was concerned when special-effects houses turned to more sophisticated technology and began shrinking their model studios, in some cases even closing them, during the mid-1980s.

Michael Joyce, a 20-year veteran of the trade and visual effects supervisor at ACME Models in Burbank, shared that concern.

“I worried about my livelihood,” said Joyce. “But I’ve always felt that both techniques work very well together.”

Indeed, Hollywood has learned that physical models and computer-generated imagery work better in unison.

As a result, almost all of L.A.’s most-sophisticated special effects firms including Digital Domain in Venice, VIFX in Los Angeles and BOSS Films Studios in Marina del Rey house their own model studios.

“The good thing that happened with the advances (in digital effects) is that (Hollywood) realized they needed models that much more,” said DeUnger.

Without the use of physical elements, computer imagery just doesn’t look as real. Even the most sophisticated computers cannot duplicate natural movements of physical objects, like the violent shaking and vibrating of a volcano miniature.

The model’s natural movement is the raw material needed by digital enhancers to make the effects life-like. Replicating that movement with computers alone is tremendously time consuming and expensive, or impossible.

“There are so many lucky accidents that can’t happen in CGI (computer-generated imagery),” says DeUnger of BOSS Films.

If a model plane is shot flying over a wet tarmac, the water will reflect light up onto the plane. That miniature might cost $2,000 to build and shoot, but creating the same effect via a computer-generated model could run $15,000.

It’s little wonder that virtually every upcoming summer blockbuster including Columbia Pictures’ “Air Force One,” Warner Bros.’ “Batman and Robin,” and TriStar Pictures’ “Starship Troopers” use physical models.

The recent 20th Century Fox movie “Volcano” provides a window into how physical models can be transformed into very realistic effects.

Local model makers built several miniature volcanoes for the movie, measuring about 6 feet high and 12 feet wide. Each began as a wood structure covered in mesh. They were each then covered with a urethane foam, clay and then meticulously painted and shaped to resemble a volcano. The completed miniatures were then filmed from a variety of angles, with different lighting and settings.

One shot was of the volcano standing alone. Then a miniature of a crowded street, complete with telephone poles and vehicles, is filmed. Another shot involves colored water being added to the miniature.

Of course, simple shots of mere physical models are far from life-like, as evidenced by any of the old Godzilla movies and innumerable 1950s’ UFO flicks in which dinnerware is suspended from strings.

But today, the shots of the phyical models are passed along to digital artists, who scan those elements and marry them, adding texture and color to the miniatures.

What was a toy-like replica of a volcano with food coloring spilling over its side is transformed into a violently erupting mountain bursting with lava. Even the most critical eye finds it extremely convincing.

Bob Hoffman, a spokesman for Digital Domain, the company producing special effects for “Titanic,” the most talked about special effects movie now in production, said a new synthesis is taking place between traditional model making and computer generated imagery. “Nothing is being replaced, everything is working in a seamless fashion,” he said.

Enid Dalkoff, a digital artist at Culver City-based Digiscope, says that man-made models serve as a foundation for computer artists.

“I do depend on the (model makers),” said Dalkoff. “I depend on their craft to do mine.”

The effects budget in mega-pictures can run in the tens of millions and the building of elaborate miniatures can take as long as a year.

For “Independence Day,” one of the highest-grossing films of all time, the miniatures, which towered as high as 30 feet in the air, took about 14 months to build. The cost for the models was about $5 million.

In the upcoming “Batman” movie, Gotham City has been constructed in miniature and took about five months to build. The cost for that was about $600,000.

The advances of digital technologies have grown so rapidly, say experts, that effects produced 15 years ago look primitive next to what computers can do today.

But those advances have not rendered old-fashioned model makers obsolete. Far from it.

Model makers are enjoying strong demand for their services these days, thanks to the immense and seemingly insatiable audience hunger for big-budget special effects movies.

But model making remains a low-pay profession, by Hollywood standards. So love of the craft, not money, remains the driving force.

“I’m not in this for the money,” said model maker Pete Gerard from BOSS Films’ model warehouse in Marina del Rey, which is sweltering one recent afternoon. “It’s much more about the energy and the rewards.”

The miniature connoisseur is an artist, a welder, a mechanic and sculptor all rolled into one. They still use the most basic materials, glue, nails and hammer.

“I do it for the challenge of creating the impossible in a short of amount of time,” says DeUnger.