For Steven Spielberg's 1993 adaptation of Jurassic Park, the director wanted to use as many practical effects as possible. If it was up to Spielberg, there would have been no CGI in Jurassic Park at all, but that would have been too expensive. Spielberg even opted to do a form of blurred stop-motion for the more difficult dinosaur scenes before eventually settling on a mix of animatronics and CGI. In the 1993 classic movie that runs a total of 127 minutes, there are actually only about 15 minutes total screen time for the dinosaurs, and in only about one-third (or 5 minutes) of that screen time were the dinosaurs fully computer-generated.

If any fans have time on their hands, they can look up the behind-the-scenes for the making of the dinosaurs, which showcases the enormous labor that went into making the creatures from conception to completion. Compare that to the behind-the-scenes featurette for Jurassic World, and the process looks a lot different. It's true that acting side by side with a giant mechanical dinosaur would probably be a little easier and inspire more fear in the actors than having to pretend the large creature is there.

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In Jurassic World and other films that rely heavily on green screen and CGI, the actors have to pretend to see whatever they are supposed to see. Actors often say that for this process, there is a lot more acting involved as it is not enough to simply react. The actors need to believe in whatever they are supposedly seeing so that the audience can believe it. The reason for this need from the actors is because there is always going to be something fake looking about a CGI creature (no matter how skillfully rendered) as opposed to something that was actually filmed (like an animatronic dinosaur).

Jurassic Park was the first film to ever incorporate both CGI and Animatronics into a live-action movie, and the finished film product was critically acclaimed for its innovations in both CGI and Animatronics. The film also led to an immediate increase in interest for both dinosaurs and paleontology as a career among adults and children. Steven Spielberg knew he would need a skillful visionary artist and team to pull off the movie, so he enlisted the help of legendary Stan Winston. Spielberg had seen Winston's work on James Cameron's 1986 film Aliens for the Queen Alien (also animatronic) and was very impressed.

But as Winston said, "There was just no comparison in the difficulty level of building that alien queen and building a full-size dinosaur." The alien queen is a fictional character with a hard exoskeleton, meaning it was lightweight and didn't have to look like a real-life version of something. Compare that to a dinosaur (a real-life animal of the past) and one can see how daunting the task must have been to make it believable. The iconic Tyrannosaurus—once finished—weighed about 9,000-12,000 pounds, and it along with some of the other animatronic dinosaurs took up to 20 puppeteers to control.

How were the dinosaurs made? Well, it started with conceptual drawings that were full-scaled. The team built the metal skeletons powered by hydraulics and electric motors. Then the team sculpted full-sized dinosaurs with clay, molded the sculpt, and made the foam latex skin for the robots. The latex skin was fitted over the animatronics and painted. The measurements for each dinosaur were calculated precisely so that the latex would work with the mechanics. Some of the dinosaurs (like the T-Rex) were so big and heavy that they became a safety hazard, and the cast and crew had to be warned when it was about to move.

Although sometimes, the cast and crew were not able to be warned when the giant Tyrannosaurus was about to move, as there were reports of the dinosaur moving on its own. This of course scared the pants off of anyone around when the animatronic creature would suddenly come to life unexpectedly on its own. It was later discovered that the T-Rex would move because of a malfunction caused by water. The scene where the Titan-sized, carnivorous animal breaks out of its cage and attacks the jeeps was a rainy scene to shoot.

Stan Winston and his team didn't account for the water absorption the foam latex skin would be doing. The Tyrannosaurus' skin filled with the rainwater, making the skeleton animatronic shudder and shake uncontrollably (how terrifying). The animatronic T-Rex had to be hand dried with towels and blow dryers in between takes to keep it from shaking. Steven Spielberg sort of wanted to make the T-Rex the heroine at the end of the film, even though it had been a villain the majority of the film. The final shot of the giant dinosaur would have looked a lot different had Spielberg not made the script change to have the T-Rex save the characters from the Velociraptors.

The Tyrannosaurus was definitely the most impressive animatronic made for Jurassic Park, and it was so heavily featured that the special effects crew even had to create two versions of the creature—one full-scale animatronic, and one of just the T-Rex head. The head was created for more intimate shots, which the full-bodied robot was not suited for due to issues with safety and control. The head had the ability to produce more intricate movements to add to the realism. Not only did the dinosaurs themselves have to be realized from nothing, but so did the dinosaur sounds.

There is little evidence to suggest what a Tyrannosaurus might have sounded like, but sound designer Gary Rydstrom took his inspiration from other sounds in nature. The T-Rex from Jurassic Park has an iconic and mighty roar that fans can instantly recognize. But that roar was actually created using the sounds of falling trees, air from a whale's blowhole, alligators, lions, and baby elephants. That entire scene where the T-Rex first appears is done so masterfully because the director allowed for the scene to be built upon sound design and tension.

Audiences don't see the T-Rex first—they hear it. As Alfred Hitchcock said, "there is no terror in the bang, only in the anticipation of it." The other famous director always spoke of the craft of suspense, where he preached the power of anticipation over shock. Spielberg knew he could either get a few seconds of a shocking big T-Rex reveal, or several minutes of the anticipation of what is to come by introducing the threat with teasing sounds and subtle environmental changes. All of these reasons and more are why fans always say that no other dinosaurs in movie history look and sound as real as they do in Jurassic Park.

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