Few scenes in Jurassic Park are as perfect as the introduction of the T. rex. From the eerie ripples in the cup of water through the horrifying dinosaur POV shots as it attacks the jeep, it shows how in command of technology and filmcraft Spielberg was at the time. A new video from Cinefix ostensibly details the clash of talents that helped give rise to the scene, but also describes an epochal shift in special effects.

In order to make the movie, Spielberg corralled a dream team of Hollywood special effects talents: computer-effects gurus ILM, practical-effects master Harry Winston, and stop-motion pioneer Phil Tippett. Originally, Spielberg intended to rely much more heavily on stop-motion in the film, even having Tippett Studio create mock-ups that still exist online. These helped show the scale of the dinosaurs with humans and created the series of shots and frames that would go on to be used in the movie itself.

But behind the scenes, ILM was already poking away at more purely computer-generated versions of some of the scenes, which Spielberg got around to viewing after his scientific consultants balked at how lizard-like the movie’s dinosaurs were looking. Spielberg managed these competing ideas by combining them, ending up with a fusion of animatronics and CGI that has gone on to dominate the way big special effects blockbusters are made. Their success even inspired George Lucas to finally get around to making his long-conjectured prequel trilogy, which—wait, that did not end up well at all. We have Jurassic Park to blame for Jar Jar Binks?