## Computer Graphics - Dec 2015

### Information Technology Engineering (Semester 4)

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.

### Solve any one question from Q1 and Q2

**1 (a)** List the method for character generation. Explain any two character generation methods briefly.(6 marks)
**1 (b)** Derive the equation for decision parameter of midpoint circle algorithm.(6 marks)
**2 (a)** Explain Scan-Line Polygon filling algorithm.(6 marks)
**2 (b)** Write matrix representation for the following 3D transformations:

i) Reflection about XY-plane.

ii) Rotation about X-axis

iii) Translation in X, Y and Z-directions

iv) Scaling.(6 marks)

### Solve any one question from Q3 and Q4

**3 (a)** Let ABCD be the rectangular window with A(20, 20), B(90, 20), C(90, 70) and D(20, 70). Find the region codes for endpoints and use Cohen-Sutherland algorithm to clop the lines P_{1}-P_{2} with P_{1}(10, 30) and P_{2}(80, 90) and Q_{1}-Q_{2} with Q_{1}(10, 10) and Q_{2} (70, 60).(6 marks)
**3 (b)** Explain ways of projecting 3D objects onto 2D screen in detail.(6 marks)
**4 (a)** Explain display file structure. Why is display file interpreter used? Which are the commands used in display file interpreter?(6 marks)
**4 (b)** Explain the different types of polygons. Also explain the various methods for testing a pixel inside a polygon.(6 marks)

### Solve any one question from Q5 and Q6

**5 (a)** Explain HSV color model and also compare it with RGB color model.(6 marks)
**5 (b)** Explain Gourand shading and Phong Shading methods.(7 marks)
**6 (a)** What is Animation? Explain the basic rules required for Animation.(6 marks)
**6 (b)** How is Polygon shading different from polygon filling? Explain Phong shading briefly.(7 marks)

### Solve any one question from Q7 and Q8

**7 (a)** Explain the technique of smoothing of curves using B-Spline.(6 marks)
**7 (b)** Give the set of equations of Bezier curve. Write the algorithm for drawing a Bezier curve section using four points.(7 marks)
**8 (a)** Explain features of any graphics tool that you had studied.(6 marks)
**8 (b)** How are fractals used to generate fractal surface? Give two examples of fractal surface.(7 marks)