In 1982 a movie called Tron issued in a new era, computer generated imagery (CGI) had been born. In those early days the effects were relatively basic and required the most powerful computers of the day. Therefore the effects were expensive and their use was limited. In 1984 the first use of CGI was made to replace model work in the film The Last Starfighter. Again the results although impressive were not life like, they were still computer graphics.
The late eighties and early nineties the CGI effects came of age. Industrial light and magic's work on films like The Abyss (1989) and Terminator 2 (1991) proved that these effects could be seamlessly merged with the live action. At this point CGI effects were used in isolated shots, with model shots still the staple of special effects. In 1992 Alien 3 rather unsuccessfully pushed the boundary further when CGI was used to replace the alien (or man in a rubber suit). This proved to be a case of jumping the gun, as the next year Jurassic Park would prove.
The mid to late nineties saw an explosion of CGI usage in movies. The concept of the summer blockbuster had been established, and this was joined by the term effect movie. Big films like Independence day used more and more CGI effects. Films like Twister used effects to simulate things other than spaceships or aliens. The first totally generated cartoon feature was produced in Toy Story. Star Wars The Phantom Menace provided completely computer generated characters. Now nearly every film and TV series from sci-fi to costume drama use CGI effects in some way or another.
Is this a good thing? Well yes and no. There is no doubt the CGI gives the film makers the ability to do things that conventional effect don't. George Lucas made this comment when preparing the special editions of the Star Wars movies. For example, the battle scenes from Independence Day contain so many individual elements that there would be no way to effectively composite the same number of model effects. They can be used to replace scenary to provide to produce locations that would be expensive, or impossible to create. They also can be used to cope with the loss of an actor during filming as used in both The Crow and Gladiator. They can be used to realistically produce and animate creatures that do not exist, dinosaurs (Jurassic Park, Walking with dinosaurs), Aliens (Alien Legacy, Starship Troopers) or dragons (Dragonheart). To this end CGI is a major benefit.
However there is a downside. Hollywood has seem to have forgotten that there are still limits to CGI. The Phantom Menace proved two of these. The first is lighting. No computer can currently deal with real lighting, it is just to complex. Even a single source of light contains a number of frequencies of light and these act differently when hitting different surfaces. Add to this the secondary light sources of reflected light, and the situation quickly becomes very complex. What does this mean? Well take for example the Jar Jar Binks character, in many scenes although he is visualised and moves well you can still tell he is computer generated, and this is manly down to the lighting.
The second problem is human interaction with CGI effects. A CGI creature, or items, that look realistic when viewed from distance or in isolation often do not integrate well with live action elements. Steven Spielberg understood this when he used Stan Winston animatic dinosaurs for the close ups in Jurassic Park. Another example is provided by Deep Blue Sea where many of the effects were produced by robotic sharks rather than CGI.
Horror movies provide another example of the limitations or misuse of CGI. Conventional effects that looked poor were often hidden, by making sure that a creature was only glimpsed, or remained in the dark. This trick often proved very effective and very scary. The current trend to slam the CGI creature in taking centre stage and revelling it in all its glory often ruins any tension, and proves an anticlimax. A example of this is the Haunting where the scare of the haunted house is defused by an obvious CGI monster.
All of this has culminated in computer effects being exclusively used in situations were often conventional effects would have been more realistic (all be it debatably more expensive, and slower to produce). It is my personal opinion that this is a very worrying and disappointing trend. Lets not forget it is just as easy (maybe even more so) to produce poor CGI as it is to produce poor model or creature effects. The question for filmmakers should not be how do we use the computer to produce the effect, but what would best method to produce the effect.
Apart from this Hollywood also seem to have forgotten that it is not just the effects that make a movie. While this is not the fault of CGI directly, the reduced cost, and overall prevalence of the effects have certainly contributed to it. Next time you watch Twister or Jurassic Park ask yourself apart from the eye candy, what was the plot like, what about the direction, or characterisation.
I firmly believe that CGI is a good thing, when used appropriately. I still think that at the current time a higher degree of realism still can be achieved with model shots (or some mix between the two formats). As for computer generated creatures, they are fine for distance work but again work best when combined with conventional make up or animatics. It would be a massive shame if the art involved in the traditional effects and the traditional methods of direction and film making are lost. CGI still has some way to come, but the future is bright indeed. Just image a new Steve McQueen movie, or more Indiana Jones with a young Harrison Ford, the technology is not that far away. Special effect have their place in movies and CGI definitely has its place in the arsenal of special effects, but its a matter of balance. At the moment I feel that the current main stream movies have this balance wrong, hopefully this will get worked out in the future.
So CGI yes, but total CGI no Thanks.