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- Computer Graphics - CG
- 2017
- PYQ
**Biju Patnaik University of Technology BPUT - BPUT**- Civil Engineering
- B.Tech
**3349 Views**- 55 Offline Downloads
- Uploaded 11 months ago

Registration No: Total Number of Pages: 02 B.Tech PCCS4401 7th Semester Regular / Back Examination 2017-18 Computer Graphics BRANCH: Civil Time: 3 Hours Max Marks: 70 Q.CODE: B224 Answer Question No.1 which is compulsory and any FIVE from the rest. The figures in the right hand margin indicate marks. Q1 Answer the following questions: Short answer type What is a light pen? List some of its important applications. Suppose a RGB raster system is to be designed using an 8 inch by 10 inch screen with a resolution of 100 pixels per inch in each direction. If we want to store 6 bits per pixel in the buffer, how much storage (in bytes) do we need for the frame buffer? What is fractal dimension? How is it calculated? Consider the line from (5, 5) to (13, 9). Use the Bresenham’s algorithm to rasterize the line. Prove that 2-D rotation and scaling are commutative if scaling factors Sx = Sy or where n is any positive integer. State the limitations of Cohen -Sutherland line clipping algorithm. Write 3-D composite transformation matrix using homogenous coordinates to scale a line AB with A(10, 15, 20) and B(45, 60, 30) by 3.5 in z-direction while keeping point A fixed. What is back face removal algorithm and why it is used? Discuss the convex hull property of Bezier curves? How it is satisfied? Find the transformation matrix for perspective projection by assuming view plane normal to z-axis at z = d and center of projection at the origin. (2 x 10) a) Explain the components of a cathode ray tube with a neat labelled diagram for electrostatic deflection cathode ray tube. (5) b) List the operating characteristics of the following I/O devices: Joystick and Plotter. (5) a) Find the pixel positions for the circle centered at (2, 0) with radius 15 using the midpoint circle algorithm. (5) b) Use DDA algorithm to draw a line from A(8, 2) to B(3, 7) while determine the pixel positions along the line and plotting those graphically that would approximate the desired line. (5) a) Describe the steps needed to tilt a 2 x 2 square, located at position (4, 2) so that its bottom edge is oriented parallel to (1, 2) vector. Provide the transformation matrix and show how the matrix was derived. (5) b) Reflect the diamond shaped polygon whose vertices are A(-1, 0), B(0, -2), C(1, 0) and D(0, 2) about the horizontal line y = 2 and about the vertical line x = 2. (5) a) b) c) d) e) f) g) h) i) j) Q2 Q3 Q4

Q5 Q6 Q7 a) Discuss the step by step procedure of scan line region filling algorithm. (5) b) What do you mean by parallel projection? Explain the different types of parallel projection. (5) a) What is window-to-viewport mapping? Given the coordinates of a window in world coordinates and viewport in normalized device coordinates. Convert the world coordinates of a given point in the window into its corresponding normalized device coordinates in the viewport. (5) b) Determine 3-D transformation matrix to scale a line AB in z-direction by 3.5 by keeping point A fixed. Then rotate the line by 45° anticlockwise about x-axis. Given A(10, 15, 20) and B(45, 60, 30). (5) a) Explain the B-Spline curve and its Blending function along with their mathematical expressions. State two advantages of a B-Spline curve over a Bezier curve. (5) b) Discuss the A-Buffer method for detecting visible surfaces and how is it different from the Z-Buffer method? (5) Q8 a) b) c) d) Write short answer on any TWO: Half toning Fractal Classification Diffused vs. Specular Reflection Virtual Reality (5 x 2)

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