# BIT 2304 COMPUTER GRAPHICS KCA Past Paper

UNIVERSITY EXAMINATIONS: 2013/2014
ORDINARY EXAMINATION FOR THE BACHELOR OF SCIENCE
IN INFORMATION TECHNOLOGY
BIT 2304 COMPUTER GRAPHICS
DATE: AUGUST, 2014 TIME: 2 HOURS
INSTRUCTIONS: Answer Question ONE and any other TWO

QUESTION ONE (30 MARKS)
a) Why are matrix representations used to describe point transformations in computer
graphics? [6 marks]
b) Describe how to represent three different 2D transformations as matrices.
[6 marks]
c) Explain how to derive a sequence of transformations to achieve the overall effect of
performing a 2D rotation about an arbitrary point. [ 8 Marks]
Consider the following figure:

d) Give a matrix, or product of matrices, that will transform the square ABCD into the
rectangle A′B′C′D′. [5 marks]
e) Show what happens if the same transformation is applied to A′B′C′D′.
[5 marks]
QUESTION TWO (20 MARKS)
Quadtrees are commonly used for encoding digital images in a compact form. The
specific cell values in the 8×8 Raster image are shown below. Generate a quadtree to
represent the following image.

! 5!
QUESTION!FIVE!(20!MARKS)!
!
!
!
!
/END!
!
QUESTION THREE (20 MARKS)
a) Differentiate between emissive and non-emissive flat panel displays. [4 Marks]
b) An RGB raster system is to be designed using an 8 inch x 10 inch screen with a
resolution of 100 pixels per inch in each direction. Calculate the amount of storage in
megabytes needed for the frame buffer in order to store 6 bits/pixel in the frame
buffer. [8 Marks]
c) Define the term ‘aliasing’ as used in graphics displays. [4Marks]
d) Discuss two major types of aliasing
[4Marks]
QUESTION FOUR (20 MARKS)
a) In detail, describe the different methods (at least 5) of generating computer
graphic models. [10 Marks]
b) In detail, describe 3 different methods of generating Animation in computer
graphics. [10 Marks]
QUESTION FIVE (20 MARKS)
a) What is OpenGL? List 2 other technologies similar to OpenGL. [5 Marks]
b) Distinguish between Programming and interactive techniques for generating graphic
models. In each give specific examples. [ 5 Marks]
c) For each of the following OpenGL commands, use a figure to depict what each
represents.
i) GL_POINTS
ii) GL_LINES
iii) GL_LINE_STRIP
iv) GL_LINE_LOOP
v) GL_POLYGON
vi) GL_TRIANGLES
vii) GL_TRAINGLE_STRIP
viii) GL_TRIANGLE_FAN