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3D Animation Rendering
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3D Animation |
Computer animation is the process used for generating
animated images by using computer graphics. The more general term
computer generated imagery encompasses both static scenes and
dynamic images, while computer animation only refers to moving
images.
Modern computer animation usually uses 3D computer graphics,
although 2D computer graphics are still used for stylistic, low
bandwidth, and faster real-time renderings. Sometimes the target of
the animation is the computer itself, but sometimes the target is
another medium, such as film.
Computer animation is essentially a digital successor to the stop
motion techniques used in traditional animation with 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.
For 3D animations, objects (models) are built on the computer
monitor (modeled) and 3D figures are rigged with a virtual skeleton.
For 2D figure animations, separate objects (illustrations) and
separate transparent layers are used, with or without a virtual
skeleton. Then the limbs, eyes, mouth, clothes, etc. of the figure
are moved by the animator on key frames. The differences in
appearance between key frames are automatically calculated by the
computer in a process known as tweening or morphing. Finally, the
animation is rendered.
For 3D animations, all frames must be rendered after modeling is
complete. For 2D vector animations, the rendering process is the key
frame illustration process, while tweened frames are rendered as
needed. For pre-recorded presentations, the rendered frames are
transferred to a different format or medium such as film or digital
video. The frames may also be rendered in real time as they are
presented to the end-user audience. Low bandwidth animations
transmitted via the internet (e.g. 2D Flash, X3D) often use software
on the end-users computer to render in real time as an alternative
to streaming or pre-loaded high bandwidth animations.
The screen is blanked to a
background color, such as black. Then, a goat is drawn on the right
of the screen. Next, the screen is blanked, but the goat is re-drawn
or duplicated slightly to the left of its original position. This
process is repeated, each time moving the goat a bit to the left. If
this process is repeated fast enough, the goat will appear to move
smoothly to the left. This basic procedure is used for all moving
pictures in films and television.
The moving goat is an example of shifting the location of an object.
More complex transformations of object properties such as size,
shape, lighting effects often require calculations and computer
rendering instead of simple re-drawing or duplication.
To trick the eye and brain into thinking they are seeing a smoothly
moving object, the pictures should be drawn at around 12 frames per
second (frame/s) or faster (a frame is one complete image). With
rates above 70 frames/s no improvement in realism or smoothness is
perceivable due to the way the eye and brain process images. At
rates below 12 frame/s most people can detect jerkiness associated
with the drawing of new images which detracts from the illusion of
realistic movement. Conventional hand-drawn cartoon animation often
uses 15 frames/s in order to save on the number of drawings needed,
but this is usually accepted because of the stylized nature of
cartoons. Because it produces more realistic imagery computer
animation demands higher frame rates to reinforce this realism.
Movie film seen in theaters in the United States runs at 24 frames
per second, which is sufficient to create the illusion of continuous
movement.
One of the earliest steps in
the history of computer animation was the 1973 movie Westworld, a
science-fiction film about a society in which robots live and work
among humans, though the first use of 3D Wireframe imagery was in
its sequel, Futureworld (1976), which featured a computer-generated
hand and face created by then University of Utah graduate students
Edwin Catmull and Fred Parke.
Developments in CGI technologies are reported each year at SIGGRAPH,
an annual conference on computer graphics and interactive
techniques, attended each year by tens of thousands of computer
professionals. Developers of computer games and 3D video cards
strive to achieve the same visual quality on personal computers in
real-time as is possible for CGI films and animation. With the rapid
advancement of real-time rendering quality, artists began to use
game engines to render non-interactive movies. This art form is
called machinima.
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For many years, I have lived
uncomfortably with the belief that most planning and architectural design
suffers for lack of real and basic purpose. The ultimate purpose, it seems
to me, must be the improvement of mankind.
James Rouse
I am but an architectural composer.
Alexander Jackson Davis
I hope that America as a whole, and especially its architects, will become
more seriously involved in producing a new architectural culture that would
bring the nation to the apex - where it has stood before - and lead the
world.
Tadao Ando
I look upon myself as a musical bricklayer with architectural aspirations.
Robert Mayer
I'd say that my profession ends where architectural thinking ends -
architectural thinking in terms of thinking about programs and
organizational structure. These abstractions play a role in many other
disciplines, and those disciplines are now defining their 'architectures' as
well.
Rem Koolhaas
I'm not an architectural composer.
Harrison Birtwistle
It fills one with a sense of architectural possibility.
Paul Goldberger
It was always my intention that The Frieze should be housed in a room which
would provide a suitable architectural frame for it.
Edvard Munch
Profit and bottom line, the contemporary mantra, eliminates the very source
of architectural expression.
Arthur Erickson
Supply and demand regulate architectural form.
Adolf Loos
The center of Western culture is Greece, and we have never lost our ties
with the architectural concepts of that ancient civilization.
Stephen Gardiner
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