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% Computer English
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% Sakari Pihlava
% 39118U
% Ti I


\chapter{Computer Graphics}
\author{Sakari Pihlava}

\section{A brief history of computer graphics.}

When the first commercial computer graphics stations appeared they
were expensive and of poor quality, in terms of pixel resolution and
colour.  They were only affordable by large institutions, government
laboratories, the military, large firms and the largest universities
which had interest in this area.

The 80's changed all this.  Computer graphics came to be part of our
daily life.  The prices dropped and the quality of display and control
devices improved dramatically.  This was due to the increasing
interest towards micro computers and personal computers. In order to
sell them and to be ahead of all rivals many research projects were
started and successfully completed.

Computer graphics is still one of the most exciting and rapidly
growing fields in computer science due to the value of the picture as
an effective means for communication, and the way computers are used
in all areas.

\section{Today's world of computer graphics}

There is virtually no area in which graphical displays cannot be used
to some advantage.  Although early applications had to rely on
expensive and cumbersome equipment, advances in computer technology
have made interactive computer graphics a practical tool.

Today we find computer graphics used routinely in such areas as
businesses, industry, government, art, entertainment, advertising,
education, re\-search, training and medicine.

\section{Computer-Aided Design}

For a number of years, the biggest use of computer graphics has been
as an aid to design. CAD methods provide powerful tools.  When an
objects dimensions have been specified for the computer system, the
designer can view and rotate the object to see how it will look when
constructed. Experimental changes can be made freely since, unlike
hand drafting, the CAD system quickly incorporates changes into the
display of the object.

Electrical and electronics engineers rely heavily on CAD methods.
Elec\-tron\-ic circuits, for instance, are typically designed with CAD
systems built for this purpose. Using pictorial symbols to represent
various components, a designer can build up circuits on a video
monitor by adding components to the circuit layout.  This helps the
designer to minimize the size of the design and the number of
components used.

Automobile, aircraft, aerospace, and ship designers use CAD in a
similar way to the electrical and electronics engineers. Their systems
have symbols related to their field but the basic idea of interactive
design is the same.  However they usually have complicated simulation
techniques included in their system. The performance of vehicles can
be tested to some extent even before the vehicles are built and he
outlook of a product can be seen.

Building designs are also done with CAD.  Architects interactively
design floor plans and the arrangement of windows and doors.  The
utilization of space in the office or factory complex is worked out
using CAD systems. Three-dimensional building models permit architects
to study the appearance of buildings in different environments.  The
most sophisticated systems even let the architect ``walk'' inside the
buildings.

\section{Graphs and Charts}

A number of commercially available graphics programs are designed
specially for the generation of graphs and charts.  Graph types such
as bar charts, line graphs, surface graphs and pie charts are familiar
to us from newspapers and TV.  These are methods of presenting
information in a way that is well understood and easy to read.
Business graphics is one of the most rapidly growing fields of
applications; it makes extensive use of graphs and charts by trying to
cope with the huge amount of information that is compiled for managers
and other individuals. Some packages include methods of producing
slides or transparencies to be used when presenting the data to an
audience.

\section{Computer Art}

Both creative and commercial art make extensive use of computer
graphics.  {\it Paintbrush} programs allow artists to create and colour
pictures on a video monitor.  This is done interactively using a
{\it graphics tablet}, a mouse or some other method of entering data.
Computer-generated art is widely used in commercial applications like
graphical user interfaces, TV and firm logos and advertising designs.

\section{Computer Animation}

This is a fairly new field of computer graphics due to the poor
quality of early graphics devices and the slow speed of early
computers. Movies like {\it Star Trek --- The Wrath of Khan} and {\it The Last
Starfighter} contain a lot of computer graphics in them.  Animation
methods are also used in education, training and research
applications. Flight simulators are now using computer animation in a
way that includes all fields of Computer graphics. Flight conditions
can be changed from snow storms to clear summer afternoons, and you
can fly to any major airport in the world.

\section{Advances in computer graphics technology}

Photo reproduction has been lately under discussion on TV and in many
magazines.  It all started when a well-known filmstar admitted to
reporters that she had used photo reproduction to improve her
appearance. She said that it is fairly common today that pictures are
reproduced by computers to make people look younger.  Due to the
development of computers and graphics software this is now possible
for all major newspictures and for the TV.

Another interesting field today is Cyberspace --- a world controlled by
computers (the term was invented by William Gibson a science fiction
author). The current research leader in this field is VPL Research
which is located in Silicon Valley, California.  Their research has
produced many innovations related to the study of virtual reality.
These innovations include the data glow which can sense the movements
of the hand and pass the information on to a computer. These
innovations are now used successfully to solve many problems like the
movement and vision inside Cyberspace.  The data glow is the key to
man's movement inside Cyberspace.  The vision is provided using a
helmet with two LCD displays fitted into it.  The hardware required to
control Cyberspace is relatively cheap and commonly used. VPL Research
uses two Silicon Graphics Iris computers , one for each eye, to
produce the graphics and an Apple Macintosh to control the virtual
reality software.  Due to the interest of the public some commercial
products will be released next year. One will be the new AutoCad which
can be used to create virtual reality buildings which can be inspected
inside a Cyberspace.

NASA is one of VPL Research's customers and is itself doing research
related to this field. NASA's project is Telepresence. People can
travel from place to place through the telephone lines. You can for
instance play tennis with your friend in Tokyo using Telepresence. The
game would take part in a synthetic environment like Cyberspace.
Telepresence could also be used for meetings and many other situations
which require travelling.

Computer graphics is growing very fast and it is already used
effectively in most fields.  People have found that graphics can make
the information much easier to understand. Graphics can also provide
us with the means of doing something that is impossible in real life.
The future will show us more surprises in the field of computer
graphics.


\section*{Glossary}

\begin{tabular}{ll}
CAD,Computer Aided Design   &   tietokoneavusteinen suunnittelu\\
control device              &   tiedon sy\"ot\"on tai tulostuksen ohjaukseen\\
                            &   k\"aytetty laite\\
Cyberspace                  &   kyberavaruus, tietokoneiden hallitsema tila\\
graphics tablet             &   levy, joka muuntaa kyn\"an liikkeen\\
                            &   koordinaatti pisteiksi\\
hardware                    &   tietokone laitteet\\
interactive		    &   vuorovaikutteinen \\
innovation                  &   keksint\"o tai idea\\
LCD                         &   tietokoneen n\"aytt\"ottyyppi\\
photo reproduction          &   valokuvien muokkaus\\
pixel                       &   piste,  joista n\"ayt\"on kuva muodostuu\\
software                    &   tietokone ohjelmistot\\
Telepresence                &   telel\"asn\"aolo; puhelinlinjojen avulla\\
                            &   tapahtuva keinotodellisuuksien\\
                            &   yhdist\"aminen yhdeksi yhteiseksi\\
transparency                &   piirtoheitinkalvo\\
user interface              &   k\"aytt\"oliittym\"a\\
virtual reality		    &	keinotodellisuus\\
\end{tabular}

\section*{References}

{\parindent=0pt\parskip=3pt
Hearn \& Baker, {\it Computer Graphics}, Prentice Hall, 1986 

Glassner {\it Graphics Gems}, Academic Press, 1990 

MikroPC, OY Talentum AB, 1/91
}


