Dr Alan Grant is stunned. He leans forward in the stationary vehicle, his mouth opening with a mixture of awe and bewilderment. Off comes the hat. He hurriedly pulls himself to his feet before clumsily taking off his sunglasses.
The oblivious Dr Ellie Sattler tries to start up a conversation, but is quickly hushed when Grant forcibly moves her head in the direction of the sight that has left him mute.
Her reaction is more dramatic. Scrambling to her feet, mouth agape, the musical score suddenly shifts from a tense build-up to a majestic orchestral harmony - as a dinosaur comes into view.
In less than a minute of screentime,Â Jurassic Park, which turns 25 this week, transformed the film industry suddenly and drastically.
Steven Spielberg's edge-of-the-seat thriller is still regarded as one of the greatest blockbusters in cinematic history. But it also stands as the most significant movie for a new kind of visual effects.
The death of stop-motion
"Jurassic Park was really the melting of the glacier," says Phil Tippett, the Oscar-winning effects expert who worked as dinosaur supervisor on the film.
1993's box office smash was a pioneer of CGI, or computer-generated imagery, which played a key element in bringing the dinosaurs to life on the screen. These days, CGI is everywhere in both TV and film. But at the time, it was revolutionary.
As a stop-motion animator, Tippett - who had worked on the Star Wars, Indiana Jones and RoboCop films - was in danger of becoming extinct in his own industry.
"[Jurassic Park] was kind of the nail in the coffin for stop-motion animation in the context of live action feature films," he tells i. "Until it was decided to run everything with CG, everything was done with a system we developed at ILM (Industrial Light & Magic), essentially a computerised live puppet."
But then, as Tippett puts it, "everything changed".
Effects find a way
Fortunately, the effects expert was adept at evolving with the times. But there was an aspect of trial and error to Jurassic Park.
Tippett and his team worked on the tense velociraptor kitchen scene (Photo: Universal Pictures)
"We were working with technology that was relatively new to all of us. It was a matter of figuring out what you could do and what you couldn't do. So that was a very vertical learning curve for everybody.
"The problem was there wasn't enough competent computer graphic animators at that time. Their training hadn't gotten them to a point where they were conversant with doing this particular kind of thing.
"All the digital work that had been done previously at ILM for Young Sherlock Holmes, The Abyss and the Terminator 2 robot were all kind of hallucinogenic things.
"When you are trying to make real animals look like they actually exist on earth it is a totally different kind of thing."
So Tippett and his team created a device that was a very early form of what is now known as 'motion capture'. Dubbed the dinosaur input device, it was essentially a stop-motion model with sensors on it.
The ideal person for the job
From an early age Tippett was inspired by Ray Harryhausen and his 1958 movie The 7th Voyage of Sinbad, developing a love for monsters and dinosaurs. This stayed with him well into adulthood, even inspiring him to make a short film involving dinosaurs.
It was a combination of his animation talents and dinosaur know-how which saw him become an influential member of the Jurassic Park team.
"I knew a bunch of stuff about dinosaurs, which was why Kathleen Kennedy and Steven (Spielberg) wanted to hire me," Tippett says. "I understood all the current paleontology, so I had some value from that point of view."
The ideas which Tippett helped contribute left an indelible mark.
He and his team oversaw the scenes at the T-Rex paddock and the velociraptors in the kitchen. But Tippett's suggestions also provided the film with other iconic moments.
In the initial story meeting with Spielberg and screenwriter David Koepp, it was Tippett who suggested changing the creature in the iconic dinosaur reveal scene to a larger one such as the brachiosaurus you see eating from a tree.
Tippett also recommended the ostrich-like gallimimus for the stampede sequence, replace the slow, waddling duck-like dinosaur in the book.
'What if the T-Rex attacked the car?'
Tippett noted certain things from Michael Crichton's source novel that could be changed in the movie. Such as the T-Rex picking up the car that Lex and Tim are in and "shaking it like Godzilla".
"That violated the physical laws of what a tyrannosaurus could really do in the real world. An idea I pitched him, was what if the tyrannosaurus attacked the car?
"He can't get through to the kids so he does what he would do normally: he would try and get the victim on their back and try and rip out the underbelly. So he flipped the car over and tries that approach."
Sparing no expense?
While John Hammond famously spared no expense in creating Jurassic Park, the film itself did not have a bottomless budget.
But this lended a certain ingenuity and creativity to the project.
"Everything was very carefully storyboarded over a period of about six months," Tippett explains. "There was not a lot of wiggle room in the budget, so everything was done very carefully to make sure the crossover between what Stan Winston [make-up effects creator] was going to do with his full scale props, and what was going to be digital dinosaurs later, would have continuity."
But despite this in-depth storyboarding, the occasional improvisation on set also resulted in some memorable moments. Such as when the team were shooting the scene where "blood-sucking" lawyer Gennaro is killed by the T-Rex.
"What had been designed in the storyboard was that the tyrannosaurus ran through the outhouse and obliterated the lawyer," recalls Tippett. "You assumed the lawyer got killed.
"We were setting up the shot and I said 'why don't we do a couple of takes where we tilt the camera up and we see the tyrannosaurus grabbing the guy and you get to see the tyrannosaurus eating the lawyer?'.
"The producers were going 'wait a minute, that's not budgeted at all'. But Steven thought it was a great idea."
As with so many other moments in the film, it has become borderline iconic.
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This article originally appeared on our sister site, iNews.