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ADVANCES OF THE 1960s
Excepted from the book, "Becoming a Computer Animator"
by Michael Morrison
Introduction
Pixar | Disney | Toy Story | Beauty and the Beast
Ed Catmull | Ralph Guggenheim | John Lasseter | William Reeves | Renderman
Advances of the 1970s | Advances of the 1980s | Advances of the 1990s
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The next big advance in computer graphics was to come from another MIT
student, Ivan Sutherland. In 1961 Sutherland created another computer
drawing program called Sketchpad. Using a light pen, Sketchpad allowed you
to draw simple shapes on the computer screen, save them and even recall them
later. The light pen itself had a small photoelectric cell in its tip. This
cell emitted an electronic pulse whenever it was placed in front of a
computer screen and the screen's electron gun fired directly at it. By
simply timing the electronic pulse with the current location of the electron
gun, it was easy to pinpoint exactly where the pen was on the screen at any
given moment. Once that was determined, the computer could then draw a
cursor at that location.
Sutherland seemed to find the perfect solution for many of the graphics
problems he faced. Even today, many standards of computer graphics
interfaces got their start with this early Sketchpad program. One example of
this is in drawing constraints. If you want to draw a square for example,
you don't have to worry about drawing four lines perfectly to form the edges
of the box. You can simply specify that you want to draw a box, and then
specify the location and size of the box. The software will then construct a
perfect box for you, with the right dimensions and at the right location.
Another example is that Sutherland's software modeled objects -- not just a
picture of objects. In other words, with a model of a car, you could change
the size of the tires without affecting the rest of the car. You could
stretch the body of the car without deforming the tires.
These early computer graphics were Vector graphics, composed of thin lines
whereas modern day graphics are Raster based using pixels. The difference
between vector graphics and raster graphics can be illustrated with a
shipwrecked sailor. He creates an SOS sign in the sand by arranging rocks in
the shape of the letters "SOS." He also has some brightly colored rope, with
which he makes a second "SOS" sign by arranging the rope in the shapes of
the letters. The rock SOS sign is similar to raster graphics. Every pixel
has to be individually accounted for. The rope SOS sign is equivalent to
vector graphics. The computer simply sets the starting point and ending
point for the line and perhaps bend it a little between the two end points.
The disadvantages to vector files are that they cannot represent continuous
tone images and they are limited in the number of colors available. Raster
formats on the other hand work well for continuous tone images and can
reproduce as many colors as needed.
Also in 1961 another student at MIT, Steve Russell, created the first video
game, Spacewar. Written for the DEC PDP-1, Spacewar was an instant success
and copies started flowing to other PDP-1 owners and eventually even DEC got
a copy. The engineers at DEC used it as a diagnostic program on every new
PDP-1 before shipping it. The sales force picked up on this quickly enough
and when installing new units, would run the world's first video game for
their new customers.
E. E. Zajac, a scientist at Bell Telephone Laboratory (BTL), created a film
called "Simulation of a two-giro gravity attitude control system" in 1963.
In this computer generated film, Zajac showed how the attitude of a
satellite could be altered as it orbits the Earth. He created the animation
on an IBM 7090 mainframe computer. Also at BTL, Ken Knowlton, Frank Sindon
and Michael Noll started working in the computer graphics field. Sindon
created a film called Force, Mass and Motion illustrating Newton's laws of
motion in operation. Around the same time, other scientists were creating
computer graphics to illustrate their research. At Lawrence Radiation
Laboratory, Nelson Max created the films, "Flow of a Viscous Fluid" and
"Propagation of Shock Waves in a Solid Form." Boeing Aircraft created a film
called "Vibration of an Aircraft."
It wasn't long before major corporations started taking an interest in
computer graphics. TRW, Lockheed-Georgia, General Electric and Sperry Rand
are among the many companies that were getting started in computer graphics
by the mid 1960's. IBM was quick to respond to this interest by releasing
the IBM 2250 graphics terminal, the first commercially available graphics
computer.
Ralph Baer, a supervising engineer at Sanders Associates, came up with a
home video game in 1966 that was later licensed to Magnavox and called the
Odyssey. While very simplistic, and requiring fairly inexpensive electronic
parts, it allowed the player to move points of light around on a screen. It
was the first consumer computer graphics product.
Also in 1966, Sutherland at MIT invented the first computer controlled
head-mounted display (HMD). Called the Sword of Damocles because of the
hardware required for support, it displayed two separate wireframe images,
one for each eye. This allowed the viewer to see the computer scene in
stereoscopic 3D. After receiving his Ph.D. from MIT, Sutherland became
Director of Information Processing at ARPA (Advanced Research Projects
Agency), and later became a professor at Harvard.
Dave Evans was director of engineering at Bendix Corporation's computer
division from 1953 to 1962. After which he worked for the next five years as
a visiting professor at Berkeley. There he continued his interest in
computers and how they interfaced with people. In 1968 the University of
Utah recruited Evans to form a computer science program, and computer
graphics quickly became his primary interest. This new department would
become the world's primary research center for computer graphics.
In 1967 Sutherland was recruited by Evans to join the computer science
program at the University of Utah. There he perfected his HMD. Twenty years
later, NASA would re-discover his techniques in their virtual reality
research. At Utah, Sutherland and Evans were highly sought after consultants
by large companies but they were frustrated at the lack of graphics hardware
available at the time so they started formulating a plan to start their own
company.
A student by the name of Ed Catmull got started at the University of Utah in
1970 and signed up for Sutherland's computer graphics class. Catmull had
just come from The Boeing Company and had been working on his degree in
physics. Growing up on Disney, Catmull loved animation yet quickly
discovered that he didn't have the talent for drawing. Now Catmull (along
with many others) saw computers as the natural progression of animation and
they wanted to be part of the revolution. The first animation that Catmull
saw was his own. He created an animation of his hand opening and closing. It
became one of his goals to produce a feature length motion picture using
computer graphics. In the same class, Fred Parkes created an animation of
his wife's face. Because of Evan's and Sutherland's presence, UU was gaining
quite a reputation as the place to be for computer graphics research so
Catmull went there to learn 3D animation.
As the UU computer graphics laboratory was attracting people from all over,
John Warnock was one of those early pioneers; he would later found Adobe
Systems and create a revolution in the publishing world with his PostScript
page description language. Tom Stockham led the image processing group at UU
which worked closely with the computer graphics lab. Jim Clark was also
there; he would later found Silicon Graphics, Inc.
The first major advance in 3D computer graphics was created at UU by these
early pioneers, the hidden-surface algorithm. In order to draw a
representation of a 3D object on the screen, the computer must determine
which surfaces are "behind" the object from the viewer's perspective, and
thus should be "hidden" when the computer creates (or renders) the image.
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