One thing I’ll vouch for:
There is very good CGI these days. The best CGI looks far better than the worst models any day of the week.
But IMHO, the best models look far better than the best CGI. Stan Winston, Rob Bottin, classic John Dykstra-- they did amazing stuff with nothing more than wires, plastic and blue screen.
That said, I will add that the one downfall to all the pre-CGI movies was the “blue screen effect”: before CGI, models could never be perfectly integrated into real-life scenes.
Even today, that’s why in, say, Return of the Jedi, the final battle sequence in space is still an outstanding showcase of special effects. . . but the Rancor looks like hell. Why? The latter has to be integrated with live action, and it shows (not to mention you’re simulating a living creature-- never easy for stop-motion models or CGI).
Personally, with few exceptions, these rules hold true today:
– CGI can do space effects very well for very cheap (I think the new Battlestar Galactica has excellent space effects, and on TV no less), but models still look better.
– CGI does animal effects MUCH better than it used to, but still not perfect
– CGI doesn’t do people very well at all, unless they move slowly, are seen at night, or employ motion capture
– CGI ruins horror movies. Give me the ol’ time blood and gore spatter.
If I had my druthers, I’d force most of Hollywood to use practical, physical effects BUT integrate them with CGI. This way, you get the best of both worlds: physical objects (with their intuitive feeling of weight and mass, something CGI struggles to capture), but they integrated into the scenery with computer effects (i.e., no more “blue/green screen lines” like in the old days).
