CS 2401 – COMPUTER GRAPHICS QUESTION BANK FOR (VII SEM IT)

CS 2401 – COMPUTER GRAPHICS QUESTION BANK FOR (VII SEM IT) 

UNIT – I 2D OUTPUT PRIMITIVES    

PART - A

1.      Compare Interactive Computer Graphics and Computer Graphics

2.      Compare Raster Scan and Random scan Systems

3.      Compare DDA and Bresenham’s line drawing algorithms

4.      Mention the areas of applications of computer graphics.

5.      Define the term Resolution, Persistence and Aspect Ratio.

6.      Mention the applications of output primitives.

7.      The endpoints of a given lines are (0, 0) and (6, 18). Compute each value of y as x steps from 0 to 6 and plot the results.

8.      Write the steps required to plot a line whose slope is between 0^o and 45⁰ using the slope intercept equation.

9.      Indicate which raster locations would be chosen by Bresenham’s algorithm when scan – converting a line from pixel coordinate (1, 1) to pixel coordinate (8, 5).

10.  Write the steps required to generate a circle using the polynomial & trigonometric method.

11.  When eight -way symmetry is used to obtain a full circle from pixel coordinates generated for the 0^o to 45 or the 90 to 45 octant, certain pixels are set or plotted twice. This phenomenon is sometimes referred to as overstrike. Identify where overstrike occurs.

12.  Derive the transformation that rotates an object point θ⁰ about the origin.        Write the matrix representation for this rotation.

13.  Find the matrix that represents rotation of an object by 30⁰ about the origin.

14.  Identify the new coordinates of the point P (2, -4) after the rotation.

15.  Perform a 45⁰ rotation of triangle A (0, 0), B (1, 1) C (5, 2) (a) about the origin and (b) about P (-1, -1).

16.  Write the general form of a scaling matrix with respect to a fixed point P (h, k).

17.  Find the form of the matrix reflection about a line L with slope m and y intercept (0, b).

18.  Find the equation of the circle (x`)<sup>2</sup> + (y`)² = 1 in terms of x y coordinates, assuming that the x` y` coordinate system results from a scaling of a units in the x direction and b units in the y direction.

19.  Let

S­­­­_x = vx _max – vx _min / wx _max – wx _min

S­­­­_y = vy _max – vy _min / wy _max – wy _min

Express window to viewport mapping in the form of a composite transformation matrix.

20.  Find a normalization transformation from the window whose lower left corner is at    (0, 0) and upper right corner is at (4, 3) onto the normalized device screen so that aspect ratios are preserved.

21.  Find out the final co-ordinates of a figure bounded by the co-ordinates (1, 1), (3, 4),     (5, 7) and (10, 3) when scaled by two units in X direction and three unit in Y direction.

            PART-B

1. Explain the basic concept of Midpoint ellipse algorithm. Derive the decision parameters for the algorithm and write down the algorithm steps.
2. Explain two dimensional Translation and Scaling with an example.
3. Obtain a transformation matrix for rotating an object about a specified pivot point.
4. Illustrate the DDA line drawing algorithm with an example.
5. Explain the steps in midpoint ellipse drawing algorithm.
6. Did you know polygon clipping? Define. Explain with flow chart Sutherland-Hodgeman algorithm for polygon.
7. Consider a triangle ABC whose coordinates are A[4,1], B[5,2], C[4,3]

a.       Reflect the given triangle about X axis.

b.      Reflect the given triangle about Y-axis.

c.       Reflect the given triangle about Y=X axis.

d.      Reflect the given triangle about X axis.

8. Explain Sutherland Hodgeman polygon clipping algorithm. Explain the
   Disadvantage of it and how to rectify this disadvantage.
9. Explain Bresenham’s Line Drawing Algorithms. And draw a line from origin to (-2, 3).
10. Magnify the triangle with vertices A (0, 0), B (1, 1), and C (5, 2) to twice its size while keeping C (5, 2) fixed.
11. Reflect the diamond – shaped polygon whose vertices are A (-1, 0), B (0, -2), C (1, 0), D (0, 2) about (a) the horizontal line y=2, (b) the vertical line x=2, and (c) the line y = x+2.
12. Describe the transformation used in magnification and reduction with respect to the origin. Find the new coordinates of the triangle A (0, 0), B (1, 1), C (5, 2) after it has been (a) magnified to twice its size and (b) reduce to half its size.
13. Show that the order in which transformation are performed is imported by the transformation of triangle A (0, 0), B (0, 1), C (1, 1), by (a) rotating 45⁰ about the origin and then translating in the direction of vector I, and (b) translating and then rotating.
14. Find the normalization transformation N which uses the rectangle A (1, 1), B (5, 3),   C (4, 5), D (0, 3) as a window and the normalized device screen as a viewport.

15.   How category of a line is find out for its visibility using region codes in when Sutherland line clipping algorithm.

            UNIT- II THREE DIMENSIONAL CONCEPTS

            PART-A

1. Categorize the 3D representations?
2. Is it necessary for Boundary representation? Justify it.
3. Define the term “space-partitioning representation”

4.      What is Blobby Object? Where it is used?

5. Compare Parallel and Perspective Projections.
6. Define Computer animation.
7. Mention the steps in animation sequence?
8. How frame-by-frame animation works?
9. What are the methods of motion specifications?
10. Compare Bezier curve and Spline curve.
11. Find the general form of an oblique projection into the x y plane.
12. What are the principal vanishing points for the standard perspective transformation?
13. Find the perspective projection onto the view plane z=d where the center of projection is the origin (0, 0, 0).

PART-B

1.      Explain 3D basic transformation with an example.

2.      Design a storyboard layout and accompanying key frames for an animation.

3.      How to specify the objects motions in animation systems.

4.      Derive the 3D transformation matrix for rotation about

(i) An arbitrary axis   (ii) An arbitrary plane

5.      Brief about select function and shut down functions.

6.      Explain the properties of B Spline. How it is differ from Bezier?

7.      How to represent an object on 3D scene?

8.      Explain three dimensional geometric and modeling transformations.

9.      Explain three dimensional Viewing and Functions.

10.  Draw the CIE chromaticity diagram and explain.

11.  Explain different types of color model in detail.

12.  The pyramid defined by the coordinates A (0, 0, 0), B (1, 0, 0), C (0, 1, 0), D (0, 0, 1) is rotated 45⁰ about the line L that has the direction V = J+K and passing through point C (0, 1, 0). Find the coordinates of the rotated figure.

13.  Find the transformation for (a) cavalier with θ = 45⁰ and (b) cabinet projections with θ = 30⁰ . (c) Draw the projection of the unit cube for each transformation.

14.  Find the intersecting points of a line segment with the bounding planes of the canonical view volumes for (a) parallel and (b) perspective projections.

15.  Determine the inequalities that are needed to extend the Liang – Barsky line clipping algorithm to 3D for (a) the canonical parallel view volume and (b) the canonical perspective view volume.

16.  Let P₀ (0, 0), P₁(1, 2), P₂(2, 1), P₃(3, -1), P₄(4, 10), and P₅(5, 5) be given data points. If interpolation based on cubic B-Spline is used to find a curve interpolating this data points, find a knot set t₀ ,…. t₉ that can be used to define the cubic B-Spline curves.

           UNIT – III GRAPHICS PROGRAMMING

PART – A

1. Define Color model and draw the table.
2. What are the uses of chromaticity diagram?
3. Write the color conversion procedures for HSV to RGB and RGB to HSV.
4. Mention the applications of color models.
5. What are the parameters in the HLS color model?
6. Differentiate local illumination model and global illumination model.
7. Name the three perceptual terms for describing color and the corresponding physical properties of light.

8.      State any four application of Open GL.

PART – B

1.    Explain RGB, CMY, YIQ and YUV color models

2.    Can we use Z to convert from chromaticity coordinates (x, y) back to a specific color in the XYZ color space?

3.    Show that when averaging or interpolating normal vectors we will get incorrect result if the vectors are not unit vectors.

4.    Verify the fact that the Y in the CIE XYZ color model is the same as the Y in the NTSC YIQ color.

5.    Write the procedure to create an object and its operations using OpenGL.

UNIT – IV RENDERING

PART - A

1. Define 3D surface rendering? List out some applications of surface rendering.
2. How do I draw 2D controls over my 3D rendering?
3. Write the Rendering Process?
4. How do I split or cut objects for 3D rendering?
5. Can I calculate the 3D volume of my 3D surface model?
6. How do I calculate the surface area of a 3D surface model?
7. Mention the steps to create 3D rendering from 2D image slices?
8. Compare pre rendering and volume rendering.

9.      How do I change the quality of line rendering?

10.  Compare Flat Shading, Smooth Shading.

11. Difference between Phong shading and gouraud shading?
12. How Phong Shading Model produces shiny spots on an object?
13. How is rendering of bitmapped images different from rendering of vector graphics?
14. What is a conceptual rendering?

PART – B

1.  Write the basic concepts underlying the subdivision algorithm? Explain with one example.
2. What is painter’s algorithm? How to apply the painter’s algorithm to display objects.
3. How can we use the special structure of a convex polyhedron to identify its hidden faces for a general parallel or perspective projection?
4. How can hidden surface algorithms be used to eliminate hidden lines as applied to polygonal mesh models?
5. Assuming that one allows 2²⁴ depth value levels to be used, how much memory would a 1024*768 pixel display require to store the z Buffer?

UNIT – V FRACTALS

PART – A

1.      Describe fractal and give any two examples of fractal.

2. What is a fractal? What are some examples of fractals
3. What is fractal dimension? How is it calculated
4. What is a strange attractor?
5. Write the steps to be compute Mandelbrot set.
6. List out the bounds of the Mandelbrot set.  When does it diverge?
7. How can I speed up Mandelbrot set generation?
8. Mention the area of the Mandelbrot set?
9. Differentiate Mandelbrot set and a Julia set?
10. Compare the connection between the Mandelbrot set and Julia sets?
11. How is a Julia set actually computed?
12. List out some Julia set facts?
13. Did you know about Iterated Function System (IFS)? Justify it.
14. What is the state of fractal compression?
15. How is Fractal Mountains generated?
16. Write about the steps to generate 3-D fractals.
17. Describe how hidden surface removal and projection are integrated into the ray – tracing process.
18. Name the three components of surface shading and the secondary ray for computing each.
19. Compare vector and ray.
20. Let the view point be at (a, b, c) and the center of pixel at (x, y, z). Find vectors s and d to represent the corresponding primary ray.
21. Determine if a ray intersects a plane that is parallel to the xy plane.

PART – B

1. Let S₁ be a sphere of radius 8 centered at (2, 4, 1) and S₂ a sphere of radius 10 centered at (10, -2, -5). Determine if a ray with S=2J+5K and d= I – 2K intersects the spheres.
2. Describe a scene where the bounding volume techniques are definitely not applicable. Explain why.
3. Illustrate why the relative size of an objects affects the quality of environment mapping.
4. The implicit equation for a cylinder of a radius R along the Z – axis is X² + Y² – R² =0. Determine if a ray s + td intersect the cylinder.