机械五班 王乘龙
Lesson 25 Computer Graphics(Reading Material)
The term computer graphics refers to the entire spectrum of drawing with the aid of a computer，from straight lines to color animation ．An immense range of artistic capabilities resides under the heading of computer graphics and drafting is just one of them．
Computer graphics was originally associated with the field of electronics ．Companies directly involved in electronics design and manufacturing were the first to experiment and work with computer graphics ．As they tested equipment and software，new demands arose that required changes and advances in both hardware and software ．Equipment and programs got better ，faster ，more powerful ，less expensive，colorful ，and fun to operate．
The potential for this new computer development was endless ．And as engineers and drafters learned to work with the new tools in a technically demanding atmosphere ，artists were using the new tools in an atmosphere of unlimited structure ．We see the structure and freedom brought by engineers and artists to computer graphics as we watch animated television network ．Complex mathematical
calculations are combined with the creative eye of the artist to achieve effects unseen just a few years ago． The world of computer graphics is a dynamic and ，at times ，volatile filed. The developments in technique and equipment have advanced rapidly ，and the areas of application continue to spread. The drafting applications of CAD are unlimited The speed-of-light capabilities of the computer have shaped the gathering ，processing ，storage ，and retrieval of information into a major industry ．Every day our lives are touched by the effects of computers ．Contrary to science-fiction works of years past，computers have not grown to occupy the core of the earth，but have shrunk to microscopic proportions ，and now occupy tiny spaces inside our machines and tools．
The tools of the drafting trade have also felt the electronic touch of computers．The silicon chip has found its way into drafting tools．The heart of modern drafting tools is now the computer ．The traditional tools of graphics ，such as the T-square ，compass ，and drafting machines(Fig．25．1)are rapidly becoming obsolete．
Now the drafter ，or operator ，uses electronic hardware to construct drawings ，not on paper ，but on what looks like
a television screen ．The screen is called a monitor ，video display screen ，or video display terminal(VDT)．The drafting process is now called computer-aided design drafting．or CADD ．Most people say “computer-aided drafting ’’and use the acronym of CAD．Actually ，CAD means computer-aided design The first commercially produced computer drafting system was introduced by IBM in 1964.Computer drafting systems began to mature and prove themselves in the late 1970s ．
Sales of computer graphics that time there has been an terminals reached approximately exponential increase in the sales twenty thousand in 1979．Since that time there has been an exponential increase in the sales of computer graphics systems．
A visit to your local industries and engineering firms will make you aware of the popularity of computer-aided drafting．But why is it so popular? Why were computers introduced as the：tool to replace the drafting machine and pencil? Why are companies scrambling to convert to computer drafting？
Foremost in your mind must be the fact that we live
in the global market economy
environment which thrives on innovation and competition ．We are always trying to outdo each other and discover new ways to make money．New technology，such as using a computer，often gives the competitive edge to one company over another．The new electronic technology has given some company an advantage because of a couple of characteristics of the computer that are not possessed by most humans．
Computers are extremely fast．The contents of an entire encyclopedia can be transmitted in a fraction of a second．Computers are accurate．
Each of these characteristics helps people increase productivity. which is the key to the success of using computer graphics ．Without an increase in productivity it is doubtful that computer graphics would have ever gained as much popularity as it has．
But a fast machine cannot account for the productivity gain by itself；it needs competent human operators ．The computer may be fast ，but it cannot think ，make judgments，nor reason．Human ，on the other hand，may be slow ，but they are intelligent and can use their
power of reasoning to solve problems and overcome obstacles 。Together ，the speed of the computer and the intelligence of the human create a good combination that is very productive．
As you continue your study of drafting and design，keep in mind that creativity has not been replace by the computer ．Only the tools have changed ，allowing entirely new horizons to be opened for exploration ．With the new tools at your fingertips，consider the limitations of your brain as the only obstacles to exploration．Enjoy your computer-aided design and drafting．
机械五班 王乘龙