GTU paper solution of Advance computer Graphics (ACG) NOvember 2013

I provides GTU paper solution of Advance computer Graphics (ACG) NOvember 2013.I solve manually all the question which are given below:

Explain axonometric projection. Derive the transformation matrix for diametric and trimetric projection.

Write the advantages of B-spline curve over Bezier curves. Prove that C2 continuity is inherent in B-spline.

Explain aliasing and its effect. Also explain anti-aliasing methods.

Explain Z-buffer algorithm for visible surface detection.

Explain Ray tracing algorithm.

Explain Warnock’s area subdivision algorithm with example. Compare it with Weiler-Atherton’salgorithm.

“BSP tree algorithm is useful for applications in which the viewpoint changes but the objects do not” justify the statement.

Explain the effects of multiple knots and multiple control points for B-spline curves with diagram.

Compare image based rendering with geometry based rendering with applications of it.

Explain global illumination and recursive ray-tracing algorithm.

 Explain gamma correction. Why it is required?

Explain halftone approximation with its application.

 Explain color model with CIE chromaticity diagram.

Define polyhedra. What is the necessary and sufficient condition for object to be a polyhedron? Mention the advantages of Winged-edge representation over other boundary representation methods.

Explain three methods for polygon mesh representation. Also represent the object shown in Fig.1 using all three methods.

Why half-toning technique is required? How it can be achieved?

  

 How do we find dominant wavelength and excitation purity of any color using CIE diagram?

Give applications of YIQ color model. Why we prefer YIQ model rather then RGB in color image processing?

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Differentiate cookie and session………[December – 2012, May – 2013]

	Cookies	Session
1	Data on Client-side	Data on server-side
2	Limited support for data handling	Unlimited side of data as per as server capability
3	only text	It can store any type of data
4	Age of data is fixed .	Age of data is not fixed .
5	Remains on client machine	Destroy after session timeout or logout
6	All cookie need to travel each time client sends request to server.	Less data traveling over the network
7	Less secure	More secure mechanism to session tracking
8	Cookies may or may not be individual for every client.	Always individual.
9	We can disable cookies.	We can’t disable session.
10	Most browsers support cookies of up to 4096 bytes(4kbytes).	Size not fixed.
11	Most browsers allow only 20 cookies per site; if you try to store more, the oldest cookies are discarded.	Number of session not fixed.

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Difference between TCP and UDP

Several Internet socket types are available:

·       Datagram sockets, also known as connectionless sockets, which use User Datagram Protocol (UDP).

·       Stream sockets, also known as connection-oriented sockets, which use Transmission Control Protocol (TCP).

The Transmission Control Protocol (TCP) is connection-oriented and transports a stream of data over a logical connection established between the sender and the receiver. As a result, data sent from a sender to a receiver is guaranteed to be received in the order they were sent.

The Connection-Oriented Sockets are based on the stream-mode I/O model of the UNIX Operating System – data is transferred using the concept of a continuous data stream flowing from a source to a destination. Data is inserted into the stream by a sender process usually called the server and is extracted from the stream by the receiver process usually called the client.     

The server process establishes a connection socket and then listens for connection requests from other processes. Connection requests are accepted one at a time. When the connection request is accepted, a data socket is created using which the server process can write or read from/to the data stream. When the communication session between the two processes is over, the data socket is closed and the server process is free to accept another connection request. Note that the server process is blocked when it is listening or waiting for incoming connection requests. This problem could be alleviated by spawning threads, one for each incoming client connection request and a thread would then individually handle the particular client.

  Program Flow in the Connection Listener (Server) and Connection Requester (Client) Processes

Connection listener(server)	Connection requester (client)
Create   connection   socket   and   listen   for	Create data socket and request a connection
connection request
Accept connection	Get an output stream for writing to the socket
Create data socket for reading from or writing	Write to stream
to socket stream
Get input stream for reading to the socket	Get input stream for reading to the socket
Read from stream	Read from stream
Get an output stream for writing to the socket	Close data socket
Write to stream
Close data socket
Close connection socket

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Installation and configuration of network simulator: NS2

NS-2 stands for Network Simulator version 2. NS-2 Is a discrete event simulator for networking research. It is work at packet level. It provides substantial support to simulate bunch of protocols like TCP, UDP, FTP, HTTP and DSR. It simulates wired and wireless network. It is primarily UNIX based. It uses TCL as its scripting language. NS-2 is a standard experiment environment in research community.

 (1) Download ns2.34

http://sourceforge.net/projects/nsnam/files/allinone/ns-allinone-2.34/ns-allinone-2.34.tar.gz/download or from anywhere else.

(2) Unzip the ns-allinone-2.34.tar.gz to any place where you want to install your ns.

Here it is  unzipped  in  /home/gz/ (note that here zipped folder of ns2 was in /home/gz)$ cd /home/gz

$ tar -xzvf ns-allinone-2.34.tar.gz

(3) $cd ns-allinone-2.34

(4) $sudo apt-get install build-essential autoconf automake libxmu-dev

(5) $./install

Errors:

It will take some time. After this step you may encounter some errors like the following

Snapshot

If you get the errors as above, follow the steps from 5.1 to 5.6, otherwise go to step (6)

5.1 $gedit otcl-1.13/Makefile.in

5.2 edit the file as follows:

old file snapshot

new file

5.3 $sudo apt-get install g++-4.3

5.4 $cd ns-allinone-2.34

5.5 ns-allinone-2.34$CC=gcc-4.3 CXX=g++-4.3 ./install

5.6 You are done if you get the following screen

(6) $ gedit ~/.bashrc

It will open the file shown below. Edit the lines that are highlighted according to your path of ns2. I installed my ns2 in /home/gz/ns-allinone-2.34

(7) $ source ~/.bashrc

(8) $cd ns2.34

(9) $./validate

It will take long time to finish(longer than the install)

If you get this screen shot, you are successful.

(10) Create a symlink, so that ns can be called from everywhere

 $ sudo ln -s /home/gz/ns-allinone-2.33/ns-2.33/ns /usr/bin/ns

(11) $reboot

To restart the system.

(12) To check whether ns is installed successfully or not, test it by entering $ns.

If you are prompted with %, it means your installation is successful otherwise check your environment variables,  specifically compare the versions of otcl, nam etc in ./bashrc with those in your ns-allinone-2.34. press exit to go back from %.

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