Computer-generated imagery (CG) is a technique using computer graphics to create images in various fields. One of its main uses is in the film industry. Computer graphics have improved along with the development of computers. The technique is so powerful and widely used that modern movies cannot be created without it. Even for the movies that do not seem to use computer graphics, there is a process called color compensation. Combined with traditional visual effects, filmmakers are able to create virtually any imagination.
CG is widely used in animated movies. Unlike other films, every frame should be produced and it requires excessive work. To save labor and improve quality, CG is used. The fact that Disney halted producing tradition hand-drawn animated films explains how difficult and cost-inefficient hand drawn animation is. Other than three dimensional animated films, animation that seems to be similar to traditional animation actually uses computer graphics. Digital ink and paints are used instead of traditional ones. This creates more dynamic and splendid scenes whereas traditional animations usually had a static background.
CG is used in adding imaginary objects that are difficult to take a video of them. As an example, extraterrestrial creatures and extinct animals do not exist on earth, so filmmakers create images of them using 3D animation software. To make them appear more realistic, a technique called motion capture is used. This process was used to create Avatar. In filmmaking, it is used to record a human actor’s specific movement for computer animation. Moreover, if a video of a huge crowd need to be taken such as a medieval war scene, filmmakers use computer graphics to increase the number of people.
The technique is good for adding objects, but it is also good for removing objects. Sometimes, removal of an undetachable part or object is needed. For example, if an actor with a normal body has to act as a disabled person with no arm, the technique is used to remove the arm from the image. Also, it is used to take videos of cities in the past by removing new buildings.
In action movies, computer generated imagery is used to produce stunt scenes. Not all scenes could be performed by actors, so filmmakers hire stuntmen and stuntwomen to do those scenes. Even if the doubles are similar to the real actor, they could not be identical. In the process of copying the real actor’s face and pasting it on the double’s face, computer graphics are used.
Still, there are two aspects in which the technique should be improved. The two are the ability to create what seems to be reality and cost. Even though the technology is near the level that the difference is not discernible, developers are continually endeavoring to make them identical. Also, the cost of computer graphics is still very high, but it is expected to be reduced by advancements in technology.