ALCCS
NOTE:
· Question 1 is compulsory and
carries 28 marks. Answer any FOUR questions from the rest. Marks are indicated against each question.
· Parts of a question should be
answered at the same place.
Q.1
a. Write the transformation matrix to get top view of an object
on the XY plane of the screen.
b. Given four control points P1(x1,y1),
P2(x2, y2), P3(x3, y3),
P4(x4, y4), work out the starting slope of a
cubic Bezier curve.
c. While performing polygon scan conversion, how
do you treat the case when a scan line passes through a vertex of the polygon?
d. Define the terms:
(i)
foreshortening factor
(ii) floating Horizon
(iii)
B-spline curve
e. Discuss the relative merits and demerits of
Z-buffer hidden surface elimination algorithm over scan line Z-buffer
algorithm.
f. Describe the diffuse and specular light
reflection modelling in computer graphics.
g.
Write short notes on:
(i) half-toning (ii) CSG
models (74)
Q.2 a. Describe the Boundary fill algorithm.
b. Using the parametric approach of Cyrus-Beck
line clipping algorithm compute the visible portion of the line segment joining
P(15, 0) and Q(15, 40) for the window area given by: P0(10,10), P1(20, 10),
P2(20, 30) and P3(10,30). Show all the calculations. (8+10)
Q.3 a. A
triangle ABC is given with vertices being A(3, 5), B(7, 5) and C(5, 10). Find
the transformation to obtain its reflection about the line y = 4x.
Also find the coordinates of the reflected triangle.
b. A unit cube located at the origin is rotated
about the X-axis by 45 degrees counter clockwise direction and then projected
on the z = 0 plane with centre of
projection at
(
0, 0, –10 ). Find the matrix transformation of the above projection? (8+10)
Q.4 a. Using integer Bresenham circle generation algorithm determine the
coordinates of the points on the arc of the circle in the 1st octant
with centre at (0, 0) having radius 7 units. Show all the calculations.
b. Derive the transformation matrix to obtain
isometric projection of an object. Use this to obtain the screen coordinates of
a rectangular box. Work out XY screen points corresponding to object
coordinates A(0, 0, 10), B(0, 20, 10), and C(30, 10, 0) (9+9)
Q.5 a. Explain
in detail depth-buffer hidden surface removal algorithm. What are its
advantages and disadvantages in comparison with scan line z-buffer algorithm?
b. Describe the method of constructing terrain
model as an example of fractals? (10+8)
Q.6 a. Control
points for a cubic Bezier curve are given by:
p0=(10, 0), p1=(20, 20), p2=(40, 20)
and p3=(50, 0). Find the parametric
equations of the curve. Draw a rough sketch of the curve.
b. Explain briefly how are the vanishing points
obtained in perspective projection.
c. Discuss the method of choosing the root node
of a Binary Space Partitioning Tree. (6+6+6)
Q.7 a. Describe
in detail the Gouraud shading algorithm. Also state its advantages over the Phong’s
shading algorithm.
b. State the components of the traditional
animation.
c. Explain a method of simulating acceleration at
the beginning followed by de-acceleration at the end between two given key
frames in an animation clip. (8+4+6)