CAD has both hardware and software components. The hardware components are Graphic display terminals, Computer and Keyboard. The software components include all computer programmes that implements computer graphics.
ICG is interactive computer graphics. It denotes a user-oriented system in which computer is used to create, transform and display data in pictorial or symbolic forms.
The input devices can be divided into three general categories. These are cursor control devices ( direct keys on keyboard, joysticks, tracker ball, etc.), digitizers (large smooth board with electronic tracking device) and alphanumeric and other keyboard terminals.
It consists of both hardware and software. Hardware includes CPU, workstations and peripheral devices. Software consists of computer programmes required to implement graphics.
The six steps are recognition of need, the definition of a problem, synthesis, analysis & optimization, evaluation and presentation.
The three primary colour red, green and blue are combined to produce variety of colours. Color CRT uses electron beams of these triad colours on phospor screen to display objects.
The five types are 2D CAD (flat drawings of product), 2.5D CAD (Prismatic models), 3D CAD (3D objects), 3D wireframe and surface modelling (skeleton like inner structure) and solid modelling (solid geometry).
Cathode Ray Tube (CRT) screen gives the user the design created as an image. It is done by entering commands to get specific functions performed.
The four categories are geometric modelling, engineering analysis, design review and evaluation and automated drafting.
They gave six ground rules which were simplicity, consistency, completeness, robustness, performance and economy.
The us of CAD system provides the better understanding of engineering drawings by standardizing them. It has fewer errors, proper documentation and greater legibility.
