AMIETE – CS/IT (NEW SCHEME)   –   Code: AC60 / AT60

 

Subject: COMPUTER GRAPHICS

Flowchart: Alternate Process: DECEMBER 2009Time: 3 Hours                                                                                                     Max. Marks: 100

 

NOTE: There are 9 Questions in all.

·      Question 1 is compulsory and carries 20 marks. Answer to Q.1 must be written in the space provided for it in the answer book supplied and nowhere else.

·      Out of the remaining EIGHT Questions answer any FIVE Questions. Each question carries 16 marks.

·      Any required data not explicitly given, may be suitably assumed and stated.

 

 

 

Q.1       Choose the correct or the best alternative in the following:                                  (210)

                

             a.  The basic objects out of which computer-drawn pictures are composed are called as_______

 

 

                  (A) polylines                                         (B) output primitives

                  (C) images                                            (D) pixels

 

             b. In a gray-scale image, eight bits per pixel produce ______ gray levels  

 

 

                  (A) 8                                                    (B) 16

                  (C) 256                                                (D) 1024

 

             c.  A plasma panel display has a _________ at each pixel location

 

 

                  (A) tiny transistor                                  (B) tiny neon bulb

                  (C) liquid crystal                                   (D) phosphor dot

 

             d.  Laying lots of copies of the same thing side by side to cover the entire screen window is called ______ the window

 

 

                  (A) zooming in                                      (B) tiling

                  (C) zooming out                                    (D) covering

 

             e.  Cohen-Sutherland algorithm is used for _____________

 

 

                  (A) line drawing                                    (B) curve drawing

                  (C) polygon filling                                 (D) line clipping

 

             f.   The most common transformations used in computer graphics are ___________  

 

 

                  (A) viewport transformations                 (B) window transformations

                  (C) affine transformations                      (D) arbitrary transformations

 

 

             g. The face list contains ________ information

 

 

                  (A) locational                                        (B) geometric

                  (C) orientation                                      (D) connectivity

 

            

             h.  Greater realism can be achieved by _______ shading

 

 

(A)  Flat                                                (B) Phong

                  (C) Gouraud                                         (D) Real

 

             i.   Flood-fill algorithm is ________

 

 

                  (A) highly recursive                               (B) not recursive

                  (C) iterative                                          (D) efficient

 

             j.   Bezier curves exhibit ________ property   

 

 

                  (A) convex                                           (B) concave

                  (C) convex-hull                                     (D) concave-hull

 

 

 

 

Answer any FIVE Questions out of EIGHT Questions.

Each question carries 16 marks.

 

 

 

 

  Q.2     a.   Distinguish Computer Graphics and Image Processing.                                        (4)

                  

             b.   Explain the three principal sources of how raster images are created.                   (6)

 

             c.   Calculate the amount of memory required for the frame buffer and colour lookup table (CLUT) in the following systems:

 

                   (i)   The system 1 has 10241280 pixel display.  It has 24 bits/pixel frame           buffer and no CLUT

                   (ii)   The system 2 has 10241280 pixel display.  It has an 8 bits/pixel frame         buffer along with CLUT.  The CLUT has 256 entries.  Each entry consists         of 24 bits.                                        (6)

 

  Q.3     a.   Explain OpenGL Data Types.                                                                            (8)

            

             b.   Write a routine drawArc(), that draws an arc of a circle, given the start angle and the sweep in degrees.                                                                 (8)

 

  Q.4     a.   What are the advantages and disadvantages of the Cohen-Sutherland line clipping algorithm?                      (4)

       

             b.   Consider a ray (described parametrically) that is hitting a line and a plane.  Find the location of the “hit points”                                                                                                               (6)

       

             c.   Write the pseudocode for the Cyrus-Beck algorithm.                                          (6)

 

  Q.5     a.   Magnify the triangle with vertices A(0, 0), B(1, 1) and C(5, 2) to twice its size while keeping the vertex C(5, 2) fixed.                                               (8)

                  

             b.   Write the matrices for the elementary 3D transformations.                                   (8)

 

  Q.6     a.   What is a polygonal mesh?  Explain with an example the various ways to

                   store information about a mesh in a file.                                                             (10)

 

             b.   Distinguish cavalier projection and cabinet projection.                                         (6)

 

  Q.7     a.   How do you create light sources in OpenGL?                                                     (6)

       

             b.   Explain Phong Shading.                                                                                     (10)

 

  Q.8     a.   Explain how you can copy a pixmap from one section of memory to

                   another.                                                                                                            (8)

 

             b.   Explain how polygon-defined region is filled using scan line method.                    (8)

            

  Q.9     a.   Explain how curves are described by means of polynomials.  Obtain the implicit functions for an ellipse, a parabola and a hyperbola.                    (10)

 

             b.   Write the parametric form of Bezier curve based on four points.  Also list the four cubic Bernstein polynomials.                                                                                                      (6)