Department of Computer Science and Engineering
University of Rajshahi
Sample Question 1
Course Title: Computer Graphics
Full Marks: 52.5
Group A (Answer any THREE questions)
Course ID: CSE3221
Time 3 Hours
1(a) What is the limitation of DDA Line drawing algorithm? What is the advantage of Bresenham’s line 3
algorithm?
(b) Describe the Bresenham’s Line drawing algorithm
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2(a) Describe Bresenham’s circle algorithm
(b) Find out the values for Y coordinates for the respective values of X coordinates {4,5,6,7} of Fig 1. With
the help of Bresenham’s circle algorithm, justify your found values for Y coordinates.
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4
3(a) Explain midpoint ellipse algorithm
(b) What will be the values for Y coordinates for the respective X coordinates {2,3,6,7} of Fig. 2. With the
help of midpoint ellipse algorithm, justify your found values for Y coordinates.
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4
4(a) Describe Cohen-Sutherland Line Clipping algorithm
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(b) Find out the clipped endpoint of the lines AB, CD, EF and GH of Fig. 3 by using Liang-Barsky Line 4
clipping algorithm ( the rectangular is the clipping window).
Group B (Answer any THREE questions)
5(a) Derive a single transformation to transform the triangle ABC to a triangle abc of Fig. 4.
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(b) Let a triangle ABC={(1,0), (0,1), (-1,0)}, apply the [T]=  3 2 on ABC, then draw both original ABD and 2.5
  1 2


(C)
Transformed ABC.
Let the position vectors of the endpoints A and B of a line AB are 1 3 1 , 4 1 1 defined in a 2.5
homogeneous coordinate system, if p=q=1 of an usual transformation matrix, then what will be
projected values of A and B on plane h=x+y+1?
6(a) Let the position vectors of vertex of a triangle ABC are 2 4 1 , 4 6 1, 2 6
position vectors of the ABC when it is reflected through an arbitrary line x-2y+4=0.
(b)
1 0 0 0
1 0 0 0 
1, calculate the




Draw, how it looks when the transformation matrix 0 1 0 0 and 0 0 0 0 are applied on the
 0 0 0 0
0 0 1 0 




0 0 0 1 
0 0 0 2 
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3
3D box of Fig. 5.
7(a) Define Trimetric, Diametric and isometric projections.
(b) Prove that the angle between the projected x-axis and horizontal line for isometric projections is 30°.
3
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8(a) What is the perspective transformation?
1
(b) What is the vanishing point? Prove that the value of the vanishing point is 1/r when XY is the 5.75
projection plane and ZC=(-1/r) is the center of projection.
(c) Differentiate between method of interpolation and approximation used in curve drawing.
2
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7
Fig. 1
Fig. 2
Y
F
a
G
b
C
c
E
B
C
H
A a
D
A
B
X
Fig. 3
Y
Fig. 4
Z
X
Z
Fig. 5