# Recent questions and answers in Computer Graphics

1
Given below are two statements: Statement $I$: Bezier curves are curves that interpolate all of their control points Statement $II$: A cubic bezier curve has four control points In the light of the above statements, choose the correct answer from the options given below Both ... $I$ is correct but Statement $II$ is false Statement $I$ is incorrect but Statement $II$ is true
2
Given below are different properties of $3D$ projections from $A-D$. Identify the correct order on the basis of property true of $(i)$ a perspective projection only, $(ii)$ an orthographic projection only, $(iii)$ both orthographic and projective transformations and $(iv)$ neither ... transformation Choose the correct answer from the options given below: d,c,b,a b,c,d,a d,c,a,b c,d,b,a
3
In the context of $3D$ Computer graphics, which of the following statements is/are correct? Under perspective projection, each set of parallel lines in the object do not stay parallel in the image (except those that are parallel to the viewplane to start with). Applying a perspective transformation in the graphics pipeline ... $(a)$ and $(c)$ only $(b)$ and $(c)$ only $(a)$, $(b)$ and $(c)$
4
Match $\text{List I}$ with $\text{List II}$. $\text{List I}$ gives $3 \times 3$ matrices representing $2D$ transformations and $\text{List II}$ shows the corresponding transformation diagrams. Choose the correct answer from the options given below: $A-IV, B-II, C-III, D-I$ $A-IV, B-III, C-II, D-I$ $A-III, B-II, C-IV, D-I$ $A-II, B-IV, C-III, D-I$
5
Concerning phong shading and Gouraud shading in a $3D$ scene, which of the following statements are true? Gouraud shading requires more computation than phong shading Gouraud shading linearly interpolates the color of an interior pixel from the color at the vertices Phong shading interpolates over the normal vectors specified at ... $(a)$ and $(c)$ only $(b)$ and $(c)$ only $(a), (b)$ and $(c)$
1 vote
6
Consider a raster system with resolution $640$ by $480$. What size is frame buffer (in bytes) for this system to store $12$ bits per pixel? $450$ kilobytes $500$ kilobytes $350$ kilobytes $400$ kilobytes
1 vote
7
Consider the following statements regarding $2D$ transforms in computer graphics: $S1: \: \begin{bmatrix} 1 & 0 \\ 0 & -1 \end{bmatrix}$ is a $2 \times 2$ matrix that reflects (mirrors) only $2D$ point about the X-axis. $S2:$ A $2 \times 2$ matrix which mirrors any $2D$ point ... statements $S1$ and $S2$? Both $S1$ and $S2$ are true Only $S1$ is true Only $S2$ is true Both $S1$ and $S2$ are false
8
Memory mapped displays are utilized for high resolution graphics such as maps uses ordinary memory to store the display data in character form stores the display data as individual bits are associated with electromechanical teleprinters
9
Below are the few steps given for scan-converting a circle using Bresenham’s Algorithm. Which of the given steps is not correct? Compute $d= 3-2r$ (where $r$ is radius) Stop if $x>y$ If $d< 0$, then $d=4x+6$ and $x=x+1$ If $d\geq 0$, then $d=4 \ast(x-y)+10, \: x=x+1$ and $y=y+1$
10
Which of the following is/are side effects of scan conversion? Aliasing Unequal intensity of diagonal lines Overstriking in photographic applications Local or Global aliasing a and b a,b and c a,c and d a,b,c and d
11
Consider a line $AB$ with $A=(0,0)$ and $B=(8,4)$. Apply a simple $DDA$ algorithm and compute the first four plots on this line. $[(0,0),(1,1),(2,1),(3,2)]$ $[(0,0),(1,1.5),(2,2),(3,3)]$ $[(0,0),(1,1),(2,2.5),(3,3)]$ $[(0,0),(1,2),(2,2),(3,2)]$
12
A Steiner patch is Biquadratic Bezeir patch Bicubic patch Circular patch only Bilinear Bezier patch
1 vote
13
Using the phong reflectance model, the strength of the specular highlight is determined by the angle between the view vector and the normal vector the light vector and the normal vector the light vector and the reflected vector the reflected vector and the view vector
14
Bresenham line drawing algorithm is attractive because it uses Real arithmetic only Integer arithmetic only Floating point arithmetic Real and integer arithmetic
15
In perspective projection, if a line segment joining a point which lies in front of the viewer to a point in back of the viewer is projected to a broken line of infinte extent. This is known as ____ View confusion Vanishing point Topological distortion Perspective foreshortening
16
Which of the following statements is/are True regarding the solution to the visibility problem in $3D$ graphics ? $S1 :$ The Painter's algorithm sorts polygons by depth and then paints (scan - converts) each Polygon on to the screen starting with the most nearest ... $S2 :$ Backface Culling refers to eliminating geometry with backfacing normals. S1 only S2 only Both S1 and S2 Neither S1 nor S2
1 vote
17
Let us consider that the original point is (x,y) and new transformed point is (x’,y’). Further Sh$_x$ and Sh$_y$ are shearing factors in x and y directions. If we perform the y direction shear relative to x=s$_{ref}$ then the transformed point is given by $x’=x+Sh_x.(y-y_{ref}); y’=y$ $x’=x; y’=y.Sh_x$ $x’=x; y’=Sh_y(x-x_{ref})+y$ $x’=Sh_y.y; y’=y.(x-x_{ref})$
18
A point P(5,1) is rotated by 90$^o$ about a pivot point (2,2). What is the coordinate of new transformed point P'? (3,5) (5,3) (2,4) (1,5)
19
In the context of 3D computer graphics, which of the following statements is/are true? P : Orthographic transformations keep parallel lines parallel. Q : Orthographic transformations are affine transformations. Select the correct answer from the options given below: Both P and Q Neither P nor Q Only P Only Q
20
In the parallel projection, the picture definition of the window to the view port, the parallel projection lines are Parallel to the viewport Perpendicular to the viewport Parallel to the window Perpendicular to the window
21
Which of the following graphics devices are known as active graphics devices? Alphanumeric devices Thumb wheels Digitizers Joystics I and II III and IV I, II and III I, II, III and IV
1 vote
22
A diametric projection is said to be trimetric projection when two of the three foreshortening factors are equal and third is arbitrary all of the three foreshortening factors are equal all of the three foreshortening factors are arbitrary Which of the above is true? I and II II and III I only III only
1 vote
23
In Cyrus-Beck algorithm for line clipping the value of $t$ parameter is computed by the relation: (Here $P_{1}$ and $P_{2}$ are the two end points of the line, $f$ is a point on the boundary, $n_{1}$ is inner normal). $\frac{(P_{1}-f_{i}).n_{i}}{(P_{2}-P_{1}).n_{i}}$ ... $\frac{(P_{2}-f_{i}).n_{i}}{(P_{1}-P_{2}).n_{i}}$ $\frac{(f_{i}-P_{2}).n_{i}}{(P_{1}-P_{2}).n_{i}}$
1 vote
24
Consider the Breshenham's line generation algorithm for a line with gradient greater than one, current point $(x_{ i} , y_{i} )$ and decision parameter, $d_{i}$. The next point to be plotted $(x _{i+1}, y_{i+1})$ and updated decision parameter, $d_{i+1}$, for $d_{i} < 0$ ... $x_{ i+1} = x_{ i + 1} y_{i+1} = y_{i + 1} d_{i+1} = d_{i} + 2 (dy - dx)$
25
Consider the matrix $M=\begin{bmatrix} 2 & 0 & 2 \\ 0 & 1 & 1 \\ 0 & 0 & 1 \end{bmatrix}$ representing a set of planar (2D) geometric transformations in homogeneous coordinates. Which of the following statements about the matrix M is True? M represents first, a ... 1) followed by shearing of parameters (-1,1) M represents first, a shearing of parameters (-1, 1) followed by scaling of vector (3,1)
1 vote
26
Find the transformation matrix that converts a square with diagonal vertices (0,3) and (-3,6) into a unit square at the origin??
1 vote
27
A graphic display system has a frame buffer that is 640 pixels high , 480 pixels high and 1 bit of color depth. If the access time for each pixel on the average is 200 nanoseconds, then the refresh rate of this frame buffer is approximately: 16 frames per second 19 frames per second 21 frames per second 23 frames per second
28
Which of the following statements is/are True regarding the solution of the visibility problem in 3D graphics? S1: The painter's algorithm sorts polygons by depth and then paints (scan - converts) each Polygon on to the screen starting with the most nearest polygon S2: Backface Culling refers to eliminating geometry with backfacing normals S1 only S2 only Both S1 and S2 Neither S1 nor S2
1 vote
29
The Liang-Barsky line clipping algorithm uses the parametric equation of a line from $(x_{1} , y_{1} )$ to $(x_{2} , y_{2} )$ along with its infinite extension which is given as : $x = x_{1} + \Delta x.u$ $y = y_{1} + \Delta y.u$ ... -Barsky algorithm is given as : $(0, \frac{2}{3})$ $\left(\frac{1}{6},\frac{5}{6}\right)$ $(0, \frac{1}{3})$ $(0, 1)$
1 vote
30
An image is 1024$*$800 pixels with 3 bytes/pixel. Assume the image is uncompressed. How long does it make to transmit it over a 10 Mbps Ethernet? 196.6 seconds 19.66 seconds 1.966 seconds 0.1966 seconds
1 vote
31
The three aspects of Quantization, programmers generally concerned with are Coding error, Sampling rate and Amplification Sampling rate, Coding error and Conditioning Sampling rate, Aperture time and Coding error Aperture time, Coding error and Strobing
1 vote
32
With respect to CRT, the horizontal retrace is defined as The path an electron beam takes when returning to the left side of the CRT The path an electron beam takes when returning to the right side of the CRT The technique of turning, the electron beam off while retracing The technique of turning, the electron beam on/ off while retracing
1 vote
33
Which of the following is not true in case of Oblique Projections? Parallel projection rays are not perpendicular to the viewing plane Parallel lines in space appear parallel on the final projected image Used exclusively for pictorial purposes rather than formal working drawings Projectors are always perpendicular to the plane of projection
1 vote
34
Which of the following is not a component of Memory tube display? Flooding gun Collector Ground Liquid Crystal
35
Which of the following color models are defined with three primary colors ? RGB and HSV color models CMY and HSV color models HSV and HLS color models RGB and CMY color models
36
Given below are certain output primitives and their associated attributes. Match each primitive with its corresponding attributes ... b-ii, c-iii, d-iv a-ii, b-i, c-iii, d-iv a-iv, b-iii, c-ii, d-i a-iii, b-i, c-iv, d-ii
1 vote
37
Line caps are used for adjusting the shape of the line ends to give them a better appearance. Various kinds of line caps used are Butt cap and sharp cap Butt cap and round cap Butt cap, sharp cap and round cap Butt cap, round cap and projecting square cap
1 vote
Perform window to viewport transformation for the point (20,15). Assume that $(X_{wmin}\ ,Y_{wmin} )$ is $(0,0)$ ; $(X_{wmax}\ ,Y_{wmax} )$ is $(100,100)$ ; $(X_{vmin}\ ,Y_{vmin} )$ is $(5,5)$ ; $(X_{vmax}\ ,Y_{vmax} )$ is $(20,20)$ . The value of $x$ and $y$ in the viewport is $x=4,y=4$ $x=3,y=3$ $x=8,y=7.25$ $x=3,y=4$