Originally Posted by CGIPadawan
To wit, it's probably because they didn't know how it would totally work that there was good overlap between Stan Winston shop and ILM.
There was a lot of attention and the testing period for the VFX was pretty extensive because it was all being done for the first time.
In particular Stan Winston shop animatronics provided a basis for the ILM CG dinosaurs to match because the point was that they wanted to cut quickly between the two with little to no difference between them.
Well, there's that. The CG had to be as good as the best animatronics, and better than the best stop-motion.
I also give a lot of credit to Spielberg himself. In his early career he made a lot of movies that were about making the incredible, credible. Making the audience believe. Too often fantasy movies are just the fantastic. You're taken for a ride, you're entertained, but you never really buy into it.
But when Spielberg was making films like Close Encounters and ET, you couldn't rely on the effects to do everything you wanted to do. This forces a lot of creativity, and Spielberg was brilliant at figuring out and capturing all the little details that really convince you of the reality he wants to portray. Of course the effects he used were state-of-the-art for the time, but what really sold them was their implementation. How and where they were used. This skill, this way of approaching things is carried over to Jurassic Park. It's in the cutting, the framing, the length of the shot, how much he shows, how little, the suggestion, the suspense, the pacing, the close ups, the acting, the reacting. So many different elements that conspire to reinforce our perception of real animals.
And the power of the film depended on this. If it couldn't deliver that sense of 'wow, a real dinosaur' it would have failed on the most crucial level. It wouldn't have become the phenomenon that it did. Getting that to work was the crux of it, the whole reason for making the movie in the first place.
You look at many films from the past decade, it's like we think we've got it all figured out. We can take anything anyone can conceive and render it photo-real. So that's all anyone does now, and they rely on the effects to sell the illusion. Along the way they wind up adding a lot of flourishes and fancy impossible camera moves, and different rendering techniques. All trying to make it look as cool and as awesome as possible. Make the shots look that extra bit more polished and sophisticated than similar movies did just a few years previous.
The cgi today looks more incredible than ever. We can depict the extraordinary, produce imagery fantastic and flawless. There's none of the giveaways of older techniques. No mismatched mattes, or strobing, or anything. Yet audiences aren't fooled for a minute. Rarely is the illusion as complete.