and the first lecture on computer graphics and this is a series of 40 lectures. So we

start with the introduction on computer graphics.

Well, computer graphics is an area of computer science and engineering which play a very

important role in almost every applications of computer software and use of computer science.

Computer graphics involves display, manipulation and storage of pictures and experimental data

for proper visualization using a computer. Typically a graphics system comprises of a

host computer which must have a support of a fast processor, a large memory and frame

buffer along with a few other crucial components. The first of them is the display devices.

Color monitors are one example of such display device. We need a set of input devices. Typical

examples are the mouse, keyboard, joystick, touch screen, trackball etc. Through these

input devices you provide input to the computer and display device is an output device which

shows you the image. There are other examples of output devices

like LCD panels, laser printers, color printers, plotters etc.

You can also have interfacing devices for a computer graphic system such as video input

output to a system or an interface to the TV. So these are some of the basic requirements

necessary to build a computer graphic system.

Well as u see now this flowchart gives the conceptual framework of interactive graphics

system. On left hand side you see an application model which the designer of computer graphics

system or software engineer will put his design. That is he will model the object he is planning

to display. Then he writes the program based on the application model. This application

program will run on the computer graphic system the output will come out to the screen and

inputs could be obtained from keyboard or from the mouse, so that is the typical framework.

There are lots of applications of computer graphics. So we will see just a few examples

of application areas of computer graphics. The first and most important of them is the

GUI as it is called. What is a Graphical User Interface or GUI as it is called? It has various

components. A graphical interface is basically a piece of interface or a program which sits

between the user and the graphics application program. It helps the graphics system to interact

with the user both in terms of input and output. Let us see few examples.

Typical components which are used in a Graphical User Interface are menus, icons, cursors,

dialog boxes and scrollbars. We will see the few examples of these in the next slide.

There are few other components which also could be used like buttons, valuators, grids,

sketching and 3D- interface. Let us take an example to see what these different components

are in typical graphical interface.

As u see in the next slide what I have done here is taken an example of Graphical User

Interface from software called Adobe Acrobat reader which is used for reading adobe documents

or PDF files.

Now this is an example which has various components of the graphical user interface which we have

talked about. You see the list of menus on the top in terms of the components on the

top screen bar and of course this is an example of what is called as a pull down menu. You

can click one of these and then what will happen is you will get a pull down menu and

adobe reader is one other example.

You can try this with various other menus and Linux based software starting from Word,

PowerPoint users, Linux, X fig and Paint Brush in Windows also so these are some of the menus.

Let us go back and see the next example is the icons and the cursor. Of course you can

see probably we can make out the cursor floating around to a point to a particular location.

These are certain examples of icons in terms of the options which will help you. The icons

are small representative pictures of tasks of computer graphics application program which

you are using. So these are certain examples of the icons, cursors, the dialog boxes.

Well, the next example does not have a dialog box. The dialog box is an example of a small

window which is used by a computer graphic system to interact with the user by sending

error or text messages. A typical dialog box is used to send an error message to the user

that you have provided the wrong input let us say. So that is an example of a dialog

box.

The scroll bar is an example, on the right hand side you can see of this window of the

example of this image which I have put here is a scroll bar which could be used to scroll

up and down.

Anything which you need to move within the screen right to left, up and down you can

use scroll bars and it will give you the current status or position of where you are in terms

of the screen location or the amount of data you are viewing. In this case the part shows

here that you are somewhere on the top part of the page or top part of the document which

you are viewing. The other examples of the graphical user interface

which is probably not in the example I have taken such as buttons, valuators, grids and

sketching. Just to give an example buttons could be considered equivalent to small icons.

Valuators could be used to control the particular value which could be linear or circular you

can assume it be a knob on a radio or a TV set which you control to control the volume

or tune it to a certain frequency or it could be in the form of a slide which you could

move from left to right or top to bottom to control a particular value to give as a input

to the computer graphic system.

Grids are used in two dimensional graphics packages to align your objects along a set

of specific coordinates or positions those are called the grids. You can switch it on

and off and display them on the screen. Sketching is an example which is used to draw lines,

arcs, poly lines and various other objects.

The most difficult part of the Graphical User Interface is at the bottom of your screen

is what is given as a three dimensional interface. It is easy to interact and handle with two

dimensional objects but when you are interacting with the three dimensional objects you need

a three dimensional interface to pick up one of the 3D objects from a two dimensional screen.

Essentially the computer monitor is just a two dimensional ray of pixels where the entire

picture is projected and the picture could represent a three dimensional scene. So you

need special type of interfaces to pick up or manipulate objects in 3D using a two dimensional

interface. So you need special facilities for 3D interface to handle or manipulate three

dimensional objects. The 3D interface is one of the hard topics of research in active areas

and the part of the Graphical User Interface.

Let us come back to other typical application areas of computer graphics. Plotting in business

we need to plot various curves in the form of pi-charts or 2D or 3D graphs.

And probably in business applications you need to show the growth rate of the company,

the expenditure, the profit and the various other types of work forces that you have been

using, various economical types of data for business applications and so you need plotting.

You need to provide for office automation which are the standard packages of Word in

Microsoft and the Microsoft Excel and PowerPoint are examples of office automation. Almost

all software has Graphical User Interface along with desktop publication for designing

documents, for designing PowerPoint slides like these you also need the help of graphical

user systems.

Plotting in science and technology, we discussed about plotting in business and plotting in

science and technology is absolutely necessary in almost all areas of study, any branch of

science and engineering and technology and I was talking of 2D or 3D graphs in the form

of line drawings, surface plots, contour plots, ISO contour plots, pi charts, so various types

of plotting are necessary in science and technology. And you probably cannot do without computer

graphic systems which has replaced the traditional draftsmen which are to take the help about

one or two decades ago for the help of plotting.

Web business, commercial publishing and advertisements you need to design very good advertisements

on the web or on the TV shows and for the commercial shoot outs may be post certain

banners outside in the city and you do take the help of computer graphics to make your

advertisement and very attractive and with that you can get a wide amount of publicity.

Coming to engineering applications we talk of CAD/CAM design when we expand those terms

it means computer aided design and computer aided manufacturing and typical example of

CAD/CAM is a vast scope in many fields of engineering and technology.

But I have taken three examples in this case VLSI Very Large Scale Integration constructions

in the area of architecture and civil engineering and circuits designs in the area of electrical

engineering. And these are the areas of CAD/CAM designs where we actually manufacture a particular

chip in VLSI or a printed circuit board let us say in a circuit or an architecture, a

bridge or road or it could be a building or a complex, a multi-storey complex we would

like to design it in a computer graphic system to have a view and provide the interface and

show what sort of design you have come up with. So there are various utilities of CAD/CAM

designs in computer graphics which play a very crucial role.

Scientific visualization is almost similar to what we talk of plotting in science and

technology. But we need to visualize something we can say as multi-dimensional data, something

which requires animation.

Let us say you would like to visualize the effect of a nuclear explosion so those sorts

of visualizations and you need to understand certain patterns in data, it could be in genetic

engineering, biological sciences or mechanical sciences or anywhere else. You would also

like to have a visualization of the scientific data and you demonstrate the activity which

is going on in a system using a typical Graphical User Interface.

Entertainment, very important, a huge market in the industry where you need computer graphics

system to design movie, TV advertisements, video games in fact almost a majority of the

market economy in computer graphic systems probably revolves around the entertainment

world where we create not only animation or carton movies but we also make real time movies

in between the real time characters.

You make advertisements with the help of real characters and merge it with various types

of steel frames, cartoon characters and things like that to create good advertisements. And

of course, video games it is a very lovely market not only for young children but even

adults get attracted to lots of video games and similar kinds of entertainment.

Simulation studies and simulators I will put both of these together. Well this is another

application I will say close to scientific visualization where you need to create a system

with a good graphical interface for various applications.

Simulation studies and simulators include areas such as computation, fluid dynamics,

heat and mass transfer, various other mechanical and chemical processors, it could include

even studies about nuclear explosion and disaster management, damage prediction in a certain

area, flight simulators. If we talk of simulators, flight simulators car racing, docking of a

naval ship or a space shuttle, you would like to train your pilots and engineers before

going on to a particular mission and you can use simulators to really test the skill of

a particular person. It could be even in the field of sports one would like to use simulators

to study the reaction time of a particular individual.

Cartography is an area which is connected to drawing, manipulation and creation of maps

as I would say. It is an area in civil engineering, geology, geography, applied geophysics and

Cartography is involved in the design of maps, creation of maps in geographical engineering

systems and for other geographical applications. Basically it has to do with the creation of

maps.

Multimedia is vast area again it combines text, audio images, video, computer graphics

everything together and the presentation must be very synchronized and computer graphics

is a very important and integrated part of any multimedia presentation.

Virtual reality, well we discussed about video games. That is probably a very classical example

of virtual reality. Or even animation movies or movies synthesized with the help of computer

graphic systems which takes you to a completely different world and you can acquire big set

of movies which have come out in the last decade based on virtual reality. Either the

movie shows itself or it can help you to design good simulators and training kids for people

before like the pilot of an aircraft, before they go on to actually test a system you can

test their skills using virtual reality systems.

Process monitoring again in chemical and mechanical processors you can have a large plans where