Above is a video of a partial animatronic (a covered skeletal armature that use various methods to mimic the motion of a human, animal, or imaginary being) test for the movie “I Am Legend” from Steve Johnson FX. It was not used in the final film, though considering the designs that were, is disappointing.
Here’s a bit of video with the CGI vampires (They’re probably actors, in motion-capture gear. Motion-capture uses technologies like blue or green screen to insert a computer generated character into a scene that moves and acts in a fluid, realistic fashion) from the aforementioned film.
Viewing the final product, it looks pretty good, though notice when the creatures open their mouths wide (around five seconds in). Their mouths open too wide, giving it a somewhat cartoonish feel. That’s because no human being can actually open their mouths that wide, though the effect would look better if there were actually an object doing it, as opposed to the computer generated work.
Here’s an example of CGI being used more effectively. This picture is from Guillermo Del Toro’s “Blade II.”
This works better than the scene from “I Am Legend” because only the lower half of the actor’s face is computer-generated (The rejected animatronic uses a similar technique, though the upper part of its face, opposed to the lower, is effected). This allows the actor–despite having to wear heavy make-up and contact lenses–to actually act.
One of the more commonly sited instances of superior practical special effects useage comes from “An American Werewolf in London”, a horror film directed by John Landis.
Looking at that transformation scene above, it wears really, really well, despite being done over 30 years ago.
Though, with the advent of cheaper and more powerful computers, it is perhaps more cost-effective for the film industry to move toward CGI to such a degree that practical effects are becoming less and less common.
Luckily, it appears that more and more film-makers see the advantage of both methods, and are using whichever best suits the scene, or even combining the technologies.
For example, arguably one of the best uses of CGI can be seen in the Steven Speilberg’s “Jurassic Park”. There are scenes in the film where the dinosaurs are fully digital creations, while in others they are animatronics.
In fact, some of the work in “Jurassic Park” is so well-done it’s difficult to determine which is which.
Other films, such as James Cameron’s “Avatar”, are a mixture of live-action and CGI-generatred worlds, environments and characters, though it differs from Jurassic Park in that when the Na’Vi come into the picture (so to speak) the entire film is CGI with actors in motion capture gear.
So, while the time where practical special effects were the only special effects may have passed, the future still looks bright for their partnership with computer generated images.