Computer Graphics - Dec 2014

Computer Engineering (Semester 6)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) Explain scan line fill algorithm. What is the use of edge table and active edge list?(7 marks) 1 (b) 1. Explain shadow mask method.
2. How long it would take to load a 640 × 400 frame buffer with 12 bits per pixel, If 10⁶ bits can be transferred per second?
Define aspect ratio. If image of size 1024 × 800 needs to resize to one that has 640 pixels width with the same aspect ratio, what would be the height of the resized image?(7 marks) 2 (a) What is aliasing? Briefly explain anti-aliasing techniques.(7 marks) 2 (b) Give advantages and disadvantages of DDA algorithm. Draw a line from (20,10) to (30,18) using DDA algorithm.(7 marks) 2 (c) (i) Explain trigonometric method for circle generation.(3 marks) 2 (c) (ii) Discuss midpoint circle algorithm with example.(4 marks) 3 (a) (i) Write 2×2 transformation matrix for each of the following rotation about origin
(a).Counter clock wise rotation by 180° (b) Clock wise rotation by 90°.(7 marks) 3 (a) (ii) Explain DVST.(3 marks) 3 (b) Clip the line using Liang-Barsky algorithm against window with (xw_min, yw_min )= (0,0) and (xw_max , yw_max )=(100,50). Line end points are A(10,10) and B(110, 40).(7 marks) 3 (c) Perform 45° rotation of a triangle A(0, 0), B(1, 1) and C(5, 2). Find transformed coordinates after rotation, (a). About origin, (b) About P(-1, -1)(7 marks) 3 (d) Write the Sutherland-Hodgeman polygon clipping algorithm. Using it clip the given polygon against the clipping window (7 marks) 4 (a) What is Bezier Curve? Define properties of Bezier Curve.(7 marks) 4 (b) What is Parallel Projection? Explain in details types of Parallel Projection.(7 marks) 4 (c) What is window and view-port? Retrieve equation for the scaling factor to map the window to view-port in 2D viewing system.(7 marks) 4 (d) Write a Short note on:
1. 3D Rotation
2. 3D Translation(7 marks) 5 (a) (i) Define: Complementary Colours, Saturation, Luminance.(3 marks) 5 (a) (ii) Explain various light sources.(4 marks) 5 (b) Explain CIE diagram with its usefulness.(7 marks) 5 (c) Explain Z buffer algorithm for hidden surface removal.(7 marks) 5 (d) Explain RGB and CMY colour models. How conversion from RGB to CMY is Done?(7 marks)