Computer-generated imagery (CGI)
is the application of computer graphics to create or contribute to images in
art, printed media, video games, films, television programs, commercials,
simulators and simulation generally. The visual scenes may be dynamic or
static, and may be 2D or 3D, though the term "CGI" is most commonly
used to refer to 3D computer graphics used for creating scenes or special effects
in films and television. The term computer animation refers to dynamic CGI
rendered as a movie. The term virtual world refers to agent-based, interactive
environments.
Computer graphics software is
used to make computer-generated imagery for movies, etc. Recent availability of
CGI software and increased computer speeds has allowed individual artists and
small companies to produce professional-grade films, games, and fine art from
their home computers. This has brought about an internet subculture with its
own set of global celebrities, clichés, and technical vocabulary.
While computer generated images
of landscapes may be static, the term computer animation only applies to
dynamic images that resemble a movie. However, in general the term computer
animation refers to dynamic images that do not allow user interaction, and the
term virtual world is used for the interactive animated environments.
Computer animation is
essentially a digital successor to the art of stop motion animation of 3D
models and frame-by-frame animation of 2D illustrations. Computer generated
animations are more controllable than other more physically based processes,
such as constructing miniatures for effects shots or hiring extras for crowd scenes,
and because it allows the creation of images that would not be feasible using
any other technology. It can also allow a single graphic artist to produce such
content without the use of actors, expensive set pieces, or props.
To create the illusion of
movement, an image is displayed on the computer screen and repeatedly replaced
by a new image that is similar to the previous image, but advanced slightly in
the time domain (usually at a rate of 24 or 30 frames/second). This technique
is identical to how the illusion of movement is achieved with television and motion
pictures.
Many judge Christopher Nolan (THE
DARK KNIGHT RISES) to be one of the more intelligent filmmakers working in the
business today. It's not hard to see why, as there's always been clarity of
intent, vision, and ideas in every one of his films. Christopher Nolan approach
to CGI is that it’s an incredibly powerful tool for making better visual
effects. But he believes in an absolute difference between animation and photography.
However sophisticated computer-generated imagery is, if it’s been created from
no physical elements and hasn’t shot anything, it’s going to feel like
animation. There are usually two different goals in a visual effects movie. One
is to fool the audience into seeing something seamless, and that’s how he tries
to use it. The other is to impress the audience with the amount of money spent
on the spectacle of the visual.
The Perfect Storm (2000)
source:
George Clooney may be a looker,
but his character in this film isn’t very smart. He plays Billy Tyne, a fishing
boat captain who ignores weather warnings, in a tale that’s based on the true
story of the Andrea Gail from 1991. The end sequence is a CGI stonker,
featuring a huge 100ft wave that finally capsizes the ship. In total, the film
featured 90 completely CG shots, all of which include water elements.
A further 220 shots required CG seas
to be composites with live-action footage shot on a huge, moveable fishing boat
set. A custom fluid dynamics system was developed to create a realistic ocean
and more than 30 plug-ins were written for Maya to achieve the intricate
effects.
How to make CGI movies
source:
Sources: wikipedia, http://www.joblo.com, youtube
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