I
f
TRIBHLTVAI.{ UNIVERS ITY
fNS TiTUTb, CIF EN GINEER"nVG
Exarmimatiom Ccratr<iE Divisiom
2$74 Ashwin
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Attempt All questions.
Thefigures in the margin indicate FulLIVIarks.
Assume suitable data if necessary.
1.
Distinguish between Raster and Vector graphics methods. When do we prefer them?
2. Digitize the line with end points A(20,10) and B(30,18) using Bresenham algorithm.
3. Clip the line P1P2 with Pl(-5,3) and P2(15,9) with clip window having diagonal
coordinate (0,0) and (10,10) using Liang-Barskey line clipping method,
4.
i5l
l1
0j
t8l
Explain the steps required to rotate an object in 3D about a line which is not parallel to
any one coordinate
axis.
tl0j
5. How Geometric tables are used to represent a 3D object? Explain with example. Give
rol
conditions to generate error free table.
Z
U,
Explain properties
control points
"|
(l,l),
LOJ
if
Bezier curve. Find the coordinate at u = 0.2 with respect to the
(4,6) (8,-3) and {12,2) using Bezier function.
t8l
Differentiate irnage space and object space method for visible surface determination.
Explain scanline method to determine visiblE surface of object.
[a+4]
8.
(1{),i0,1)
(1,1 0, I )
{I
,5,0)
(1,1,-1)
10,1,1)
:
Find out intensity of iight reflccted from the midpoint p on scan iine y 3 in the *bove
given figur* using Gcwaud shading rnodel. Consi<ier a single po'int light source located at
positive infinity on Z-axis amd. assuine vector to the eye as (1,1,1). Given d = 0, K * l,
Iu - l, Ir * 10, Ks:2, Ka: Kel:0.8 for use in a simple illumination rnodel.
9.
What is OpenGL? Explain Callback Funetion.
ff
5i< 5F
u21
14+21
-l
24
Exarn.
TRIBHUVAN UNI\ERSITY
INSTITUTE OF ENGINEERING
LeVel
Examination Control Division
2074 Chaitra
BE
i Programme BEX, BCT
m/r
Year / Part
Full Ularks
80
Marks
Time
)L
Pass
i
nfs.
Swbject: - Co
,/
"/
'/'
,/
1.
2.
a
4.
5"
Canrlidates are required
Attern;st Ail questions.
t* give their
ansrvers in their olvn words as far as practicabie.
figttres in the margin indicrtte Full Murks.
,4-csume suitable data iJ'necessart*.
The
What dq: you understancl by raster display technology'l Suppose a RGB raster s5'stem is to
be designed using an 8 irrch by 10 inch screen ra'ith a resolution of 100 pixeis per inch in
eacir direction. How long wouki it take to load this raster system in frame buffer u,'ith 24
bits per pixei, if 10s bits can be transferred per seconcl?
Horv decision parameters ean be used to drarv circle? Calculate the points to drau'a circle
[4+6]
having radious 5 and oenter as 1'10, 5).
Explain Sutherland-Cohen clippirrg algorittun wittr an example.
t8j
Find the coordinate at U : 0.25, U : 0.5, and U : 0.75 with respect tqr the controi pcints
(2. 10), (6,2A), 02, 5) and (16, i5) using Bezier function. And plot Bezier orirve with
your catrculated coordinates.
[6+2]
Describe 3*D viewing pipelining. Derive the transfbr:nation matrix
for
prespective
projectlon.
6.
7.
[6+6]
How the geometric anri attribute inforrnation of a 3-D objects are stored for the
representation? Explain rvitlr examples.
obrjeet
I5.l
What are the consideration factors to choose the Visible Surface l)etection Algorithm?
V/hat are the two classes of visible surface detection teehniques, expiain? What is
limitation of Z-Buffbr rnettrod? Ilow does A-Buffer rnethod overcome it, Explain?
L Develop a phong illumination model. Show how-this model is used for rendering
-ohading.
function with example in openGl.
deriving of expression for phong
9.
t6l
Explain callback
*t*
[12]
hy
[6+8]
l-5]
Ii*;:-----
TRIBHUVAN TINIVERSITY
Examination Control Division Ii-iip.og.urr*"
2073
Shrawan
1l
Subjec
i vgTl_p11!
New Back (o,066 & Later Batch)
i BEx,
ect
.I[ l!
pompul._e1 p_rapLricg
i p;* Mr;k
-T;.---
,Ii-"
:
:
l,i'.
1
i
(nx!-w/
'/ Candidates are required to give their answers in their own words as far as practicable.
,/ Attempt All questions.
,/ TheJigures in the margin indicate Full Marks.
y' Assume suitable data if necessary.
systems.
2. Derive and write midpoint algorithm for drawing a circle.
1.
Differentiate between vector and raster scan
t4]
[5+5]
3.
What are the different steps of two dimensional world to screen viewing transformation?
Describe with matrix representation at each steps.
t5]
4.
Obtain the end points of the line that connects P1(0,120) and P2(130,5) after cohensutheland clipping. The clip window has the following parameters.
t5l
Xo*in = 0, yo.in
5. Describe
parallel
6.
7.
:0,
xcD_*
:150 and yro_o :100
three dimensional viewing pipelining. Derive the transformation matrix for
projection.
[4+6]
Explain about parametric cubic curve? What is a Bezier Curve? Explain its properties
with examples.
[2+6]
Explain boundary representation technique to represent three dimensional objects with
suitable example.
t8l
8. Compare
object space method with image space method. Explain, How Back-face
detection method is used to detect visible surface. Also explain z-Buffer method.
12+4+4)
9. Define and explain the term ambient
appropriate mathematical
light, diffuse reflection and specular reflection with
expressions.
rendering.
11. Explain about Open GL and call back functions.
10. Explain the method of Phong shading for polygon
{.
{< {<
t7)
17)
t6l
34
TRIBHUVAN TINIVERSITY
INSTITUTE OF ENGINEERTNG
Examination Control Division
2073 Chaitra
Year/Part :lll/l
Subject: - Computer Graphics (8X603)
Candidates are required to give their answers in their own words as far as practieable.
Attempt All questions.
The.{igures in [he ntargin inc{it:ute Full Marks.
A s sume s uitabl e c/atu i{ n ec e.,e,t./1'},.
1.
2.
3.
4.
Calculate the size of frame buffer required to store a 640x480 B and W video of length 5
minutes without compression.
t4]
Discuss the Digital Differential Analyzer (DDA) line elrawing algorithrn in detail" Also
give its advantages and disadvantages.
[S+4J
A triangle A (15, 20), B (20, 30) and C (30, 20) lies inside a winclow (10, 10), (40, 50).
Find the final image of this triangle after transforming into the viewport (0, 0), {20, 2q.
Show all transformation steps.
t8]
Briefly explain various projections? Find the new coordinates of a unit cube 90o rotated
about an axis def,rned by its endpoints A (2,i,0) and B (3,3,1).
[3+7]
5" Explain
vertex, edge and surface table using a suitable example. What are the guidelines
to generate error free table?
l5+5]
6. Explain about parametric Cubic curve? What is Bezier curve? Explain
7, Disouss back face removal algorithm? Describe its limitation.
8. Compare Gouraud shading and phong's shading in detail.
9. Why Open GL required? Explain call back function.
***
its
properties.
l,_2+3+47
,
[B+2]
[g]
t8l
TRIBHUVAN TINIVERSITY
INSTITUTE OF ENGINEERING
Exarnination Control Division
I}K]X. tsCT
Z0T2Karti,6.
Swbiec| ; Campuler Graphic-s (EX!!l)
Candidates iu"e requireil to give their answers in theil own wr;rds as far as practicable.
Attempt AEquestions.
The
"figures in the rnargin indicate {yltr!4$rk "
As xmte suil.able data if' neces sary.
1.
Derive the Bresenham's decision paranlste to draw a iine moving frorn ietl tc right ancl
having negative slope. State the condition to identif,r you are ir ttre seeond regicrn of the
ellipse using rnid point algorithm.
[8+2]
2. Write dorryn the eonrlition for point
clipping. Find the clipperi region in winilow of
(i00,100)
(10,10)
diagonal vertex
ancl
f,rr line Pr (5,120) and P: (80,7) using
I-iang-tsarsky line clipping rnethad"
3.
4.
5.
6.
7.
[2+8]
Find the transfq:rrmation matrix the transfcr:r:as that rectangle ABCD r,vhose ceirter is at
(4,2) is reduced to half of its size, the center wili remaiu sarrte.'Ihe co-ordinate of ABCL)
are A(0,0), B(0,4), C(8"4) and D(8,0). Find Coordinate of ne'*", squaro. Also derive the
transfomration matrix ier convert this rectangle to square,
List out the properties of Bezier clrrl'e. What is order cf cortiuuity?
ltlj
Explain the significa.nce i:f spatial r-:rientation of a sr;rfuce and pol;vgon tatrles. Explain
with exarnple.
i8j
Ccmpare Z-buffer and A-Euffbr algorithm. Also write algoritlun to find r.isible surfaces
using s*rn-line method.
[10]
Expiain the general illurnination rnodel" Fior,v tiris rnadel is usecl tbr renderirrg by using
shading.
Write short notes on:
ai Raster scan displa_v
gouroud
8.
Explain.
[10]
b)
[7+7]
[5+5]
OpenGL
**i€
TRIBHUVAN TINIVERSITY
INSTITUTE OF ENGINEERING
Examination Control Division
2072 Chaitra
$ub-ie_ct1
Regular
Exam.
Level
BE
Programme
BEX, BCT
Year
/Part
fit
pompgler G*raphics
lI
Full Marks
Pass Marks
Time
',:
80
32
3 hrs.
(
(EX6 03)
Candidates are required to give their answers in their own words as far as practicable.
Attempt All questions.
Thefigures in the margin indicate Full Marks
Assume suitable data if necessary.
technologies?
1.
What are the differences between random and raster display
2.
How do you apply symmetry concept while drawing circle? Calculate the point in the
circumferences of the circle having radius 8 unit and center at (-5, 10) using midpoint
circle
14]
algorithm.
[2+g]
What are the conditions for a point ctipping? Find the clipped region of the line with
endpoins (5, 130) and (50, 5) in a rectangular window *itr,
tto, l0) and (100, 100)
diagonal vertices using cohen-sutherland line clipping algorithm.
4.
I10l
What is 3D Shearing? Write its matrix representation. A unit length cube with diagonal
passing through (0,0,0) and (1,1,1) is sheared with respectto yi place with
the shear
constants :2 in both direct'ions. Obtain the coordinates oiall the corners of the
cube after
shearing. [2+8]
Explain about parametric cubic curves. What do you mean by Bezier Curve? Explain
the
properties of Bezier curves.
l2+2+41
6. Expla,in how the geometric and attribute information of a three dimensional
objects are
stored for the object representation? What are the conditions for error free generation
of
polygon table?
5.
14+41
7.
Outline the Z buffer algorithm. List the advantages and disadvantages of the z-buffer
algorithm.
8.
9.
16+2+21
Explain about different types of lighting sources and how these light sources affect the
illumination model? Explain about the intensity interpolation surfaci rendering technique
by highlighting its pro and cons. Also give example alout phong illuminations}odel.
[3+5+6]
why GLUT is implemented in openGl-? what are the applications of openGl?
12+41
***
-
/*
.r:"r*r
;
-:ae'@W,.ER-SITy,,-".p
!-- :
. INSTITUTE OF ENGTNEERTNG
Exarnination Control Division
_:.
:.
.
207I Shawan
- Cgrypgtg!9ryphf. s (EX6Q 3)
Thefigures in the margi* indicate Full IVIarks.
Assume suitable data if necessary.
t.
C-onsider a raster scan system having 12 ineh by 10 inch screen with a resolution of 100
pixels per inch in each-direction. lItn" display controller of this system r.n it", tt
screen at the rate of 50 frames per second, how many pixels coutd be accessed per second"
+.
2. What is scan conversion? Derive the Bresenham's decision pararneter to draw a line with
negative slope and
lml>l
3.
a
^
[2+g]
Glen a clipping window A (10, t0), B {4d/4&t, C{40,40) and D(10,40). Using
cohen-sutherland line clipping algorithm find region code of each end poinrs of linei
PlP2, P3P4 and P5P6 where co-ordinates are Pl (5,15), p2(25,30), p3(15,i5), p4(35,j0),
P5(5,8)andP6(40,15).Alsolrndclippediinesusingaboveparameters
4.
5.
6.
8.
Perform rotation of a line (10- 10, 10), (20,20,
by90 degree. Explain about vector display.
l5) about Y-axis in clock wise direction
Derive the equation lor cubic Bezier curve. Also write down its
[6+4]
properties.
t8]
''
Explain how the 3D object is represented using poll,gon table representation technique?
Explain any one technique to calculate the spatial orientation of the individual surface
component of 3D objer:t.
[4+4]
Describe scan line method to f,rnd visible lines with exampte,..
tl0]
condition(s) flat shading gives accurate rending? Mention the disadvantage of
JJnder.what
intensity integpolation technique zurd explain Phong shading with necessary mathematical
calcuiation. Explain the diffuse refl.ectionI +6+4]
9. Why GLUT is
[3+
implemented in OpenGL? Explain OpenGL syntax ro drarv
parallelogram having verticals (0.0,0.0), (1.0,0.0), (1.5, 1.2) and (0.5,1.2).
+**
a
lZ+41
:11:-
,
I
34
TRIBHUVANUNIVERSITY
i-Ed;:
INSTITUTE OF ENGINEERING
Examination Control Division
207l Chaitra
ils;;;;
YearlPart ititlt
Full Marks
80
32
ILry-"--
Subject: - Computer Graphics (EX603)
Candidates are required to give their answers in their own words as far as practicable.
Attempt 4Equestions.
Thefigures in the margin indicote FulWIarks.
Assume suitable data
l.
if necessary.
Differentiate Random and Raster display
technology
t4l
2. Compare between DDA and Bresenham's line drawing
algorithm. Derive and write mid[10]
to the reflection along the X-axis followed by
counter clock wise rotation by cr (alpha) Degree. Find the angle cr.
u0l
ellipse.
3. The reflection along the line y: x is equivalent
point algorithm to draw
4.
Write rotation matrix in clockwise direction with respect to x-axis, y-axis and z-axis. Rotate
the object (0, 0, 0), {2,3,0), (5, 0, 4) about the rotation axis y:4.
[3+71
5.
Write down properties of Bezier curve. Find equation of Bezier curve whose control points
are P0(2,6), Pl(6,8) andP2(9,12). Also find co-ordinate of point at u: 0.8.
tl0]
6.
Explain boundary representation technique to represent the 3D object with suitable example.
How can you find the spatial orientation of a surface?
[S+2]
Explain z-buffer algorithm along with necessary steps needed to calculate the depth. What is
its drawback?
tl0l
7.
8.
Define the terms:
i10j
i)
Ambient light
Lambert cosine law
iii) Diffuse reflection
iv) Specular reflection
ii)
Also find eciuation for intensity of point by using Phong illumination model.
9.
What is openGl-? Explain callback function.
***
l4+2
/
-
t J\....:
i.
i
-:ji i,1Ei, :.
::
Examiuation Controt'Divisio
?O?O A choil
. -.::: ' '
il'
n
L
.Sibjbit:'- Comput., G|"phrcs @x603/ 'I
..
.. "j'
/
'/
',/
words as far as practicable.
their answers in their
' : own
\
:
"e
"
'L-''"'1-'r'v '-'= ": :r-. :" : "::et|iiipi\[q:iirii{;fl'i
Candidates are reouired to sive
'
Thefigures in the margin indicale FutL Marks
Assume suitoble data if necessary.
iniage to one that is 640 pixels wide with the satne
ratio, what would be the height of the resized image?
i4l
What is the advantage of,Bresenham's aigorithm over DDA algorithm for line drawing?
Use Bresenham's algorithm to scan convert a straight line connecting the end points
(20, 10) and (30, 18)
l3+7)
l- I[we want to resize at 1024x768
aspect
2.
'{'
::a
.
3.
Derive the 2D transformation matrix for rotating an object by angle 0 about a
pivot point
(xr, y,)
4.
Obtaiq perspective projection co-ordinates for the pyramid with vertices of base
(15, 15:_10}-Qql?qr-rcU (25, 15, I0), (20,'10, 10) and apex (20, 1.5,20); given that
Zprp = 20 and
5,
Zvp:0.
What is the difference between an interpolation spline and an approximate spline curve?
Explain how to satisfy Co and Cr continuiry conditions when joining two Bezier curve
sections together.
6.
Describe with iilustrate how polygon tables may be used to organize geornetric data for
polt gon surlaces boundary representation.
.
I{ow can you calculate depth of pixels and }row it can be used to detect visible surface in
1
::
-,' .
tight.
Explain the Ph6ng Shading model for pollgon-rendering.
i 0. Explain open GL with suitable examples.
1 1. Write short notes on.
8.
9.
Derive the total diffuse reflection cquation. including ambient
a) 2D translation
b) Appiication of 3D transformation
c)
Dlfference of image space and object space techniqucs
t8]
t8l
t6l
t6]
l3x2l
-
1.
,
2.
3.
d
1.
Howldueh tirne is spent scanning across each raw of pixels during screen refresh on a
rastersystem with resolution 1024x768 and a refresh rate of 60 frames per second?
t4]
Mention the disaclvantages of DDA method. Write the complete Bresenham's line
drawiry,,algorithm and using midpoint'circle d.rawing algorithm calcu-late the co-ordinate
on the:Erst quadrant of a circle having radius 6 and centr. lZO,t O;
[2+4+1j
State the
conditions of point clipping. Perfcrm clipping operation for.the following'using
Liang Barskey line clipping aigotithm:
L2+6)
Clipping window: Q(min, Ymin) = (2,5) and (Xmin, Ymin)
Line:(xl,
yl):
:
(35,50)
(-2,2) and (x2,y2): (45,40)
4.
Define window and view port. Describe three dimension u'indows to view port
transformation with matrix representation for each step. Derive oblique projee[ion matrix
with necessary assumptions.
[+4+5]
5.
DefineHermite lnterpolation in defining a curve. Use it to find the blending function ola
parametric cubic curve in 2D gTphtpt
6.
Describe polygon.
V"rtei?a
Edge table of polygon. Hor.v these terms are important in
computg-r.,graphics.
t1
t8l
Describe z-buffer rnethod for visibie surface tietection
reeomrnended method that addresses it.
8.
9.
Caiculate the
L2+61
in aetail.
S,* iir limitation and
totalintensity using phone secular reflection model by considering
[7+3]
al1 type
of light sources.
t8l
Compare:md Contract betr.r'een Gouraud and Phong Shading Model.
t8l
10. Write short notes on:
a)
b)
{3x2)
Call back frrnction
Open GL
- .-_1, :!_..
--..
,
' Subject:
-'Cornp.uter, Graphi:cs (EX 603)
:
'
. :-i:
_ - '' r:''- .':a,
1:
.''
[1+3]
[8+21
[6]'
[4+61
t8l
.{
[8]
[10]"
[4+5]
-1"
)i.
"vditex.
10. WriG shorr notcs on:
[z+4)
-i.
14xzl
f.
l
J)
o '1.
i
r,
Division
j '
i. t:.
S.ibj ect:
:
Computer Graphi cs (EX6 0 3)
l. nptive decision Barameters for midpoint circle atgorithm assuming the start positio'n
as,(r, 0) and points are to be generated along the curve path in counter clock wise order.
W[ut is slmmetry
2.
Explain the
scaling
3.
4.
[8+2]
two dimensional viewing pipeline. Derive the 2D transformation matrix for
with respect to an arbitrary fixed
How can you
Explain.
What
properfy?
point.
[4+6]
perform three dimensional rotations of an object about some arbitrary axis?
t8l
is Geometric table? Construct a Geometric table for considering an object having
formed from 6 vertices and 8 edges. ''
srrrfaces
l:r
:
3
[2+6J
5.
How can ;'oii .,-ir:,del a curved surface using polygons only,? E,xplain the use of polygon
tables for boundary representations.
[3+5]
6.
What is the difference between object space method and image space method for visible
surface determination? Explain the Z-buffer method for visible surface determination.
[3+7]
7.
8.
9.
Exptain the Phong illumination model for specular reflection.
iv)
Explain the Gouraud Shading intensity-interpolation scheme for polygon-rendering.
Lll
Why open GL required? Explain with examples.
t6l
10. Write short n6tes on:
r'1
9.1
._
[2x3]
a) Applicationvof computer graphics
b) Two-point perspective projection
'
ri.:
**t
TRIBHTIVAN I.INIVERSITY
INSTITUTE OF ENGINEERING
Examination Control Division
2068 Chaitra
Exam.
Level
Programme
Year I Part
BE
BEX, BCT
m/I
Regulal'
Full Marks
Pass Marks
Time
80
i/,
3 hrs.
Subject: - Computer Graphics (E,X603)
,/
/
'/
{
1.
2.
A
5.
Candidates are required to give their answers in their own words as far as practicable.
Attempt 4!! questions.
The Jigures in the margin indicate Fail Mstrks.
Assume suitable data dnecessary).
What is the size of flame buffer required to storc a SVGA with 24 bit true color video of
10 min without
compression?
algorithrn.
tind the composite transformation matrix for reflection about a line y : mx+c.
Digitize the endpoint (10, 18), (i5, 8) using Bresenham's
Find the new coot'dinates of a unit cube 90"-rotated about an axis defined by its endpoints
A(2,1.0) and B(3,3,1).
t4]
t8]
18]
l8l
Why 3D graphics is more complex than 2D graphics'? Explain ',vitir the help of viewing
pipeline.
t8l
6. Explain about parametric cubic curve? $'hat is a Bezier Curve? Explain its
properties. [3+3+2]
7.
Explain how the geometric and attribute information of a three dimensional objects are
stored for the object representatic'n? What are the conditions for error free generation of
polygon table?
[5+3]
8.
Differentiate between image space and object space methods of visible surface detection.
Describe A-Buffer method of visible surface detection.
[4*6]
9.
Explain the Gourad shading for polygon-rendering and cornpare it with phong shading.
[8+2]
10.
Write short notes on: (any two)
laxzl
a) Specular Reflection
b) Midpoint circle decision parameter
c) Application of OpenGL in Computer
Graphics
{.**