## BIM/Fifth Semester/ITC 221: Computer Graphics

**Candidates are required to answer the questions in their own words as far as practicable.**

**Group ‘A’**

1. Brief Answer Questions: 10×1=10

a) What do you mean by refresh rates?

b) How many k bytes does a frame buffer need in a 600×400 pixel?

c) What do you mean by symmetric property of circle?

d) Differentiate between uniform scaling and differential scaling.

e) Why projection is needed in computer graphics?

f) Define polygon table and polygon meshes.

g) List the buffer used in visible surface detection?

h) Define polygon rendering and illumination model.

i) What is the value of specular reflection parameter for dull and rough surface?

j) What is simulation?

**Group ‘B’**

Short Answer Questions: 5×3=15

2. List the applications of computer graphics and explain briefly.

3. Write the mid-point circle algorithms.

4. Derive the transformation matrix for fixed point rotation.

5. Explain scan line method for visible surface detection.

6. Explain phong shading model for polygon rendering.

**Group ‘C’**

Long Answer Questions: 3×5=15

7. a) Resterize the line with end point (10, 12) and (16, 20) using Bresenham’s line drawing algorithms.

b) Magnify the triangle with vertices A(0, 0, 0), B(1, 1, 1) and C(5, 2, 3) to twice its size while keeping (5, 2, 3) fixed.

8. a) Use the Cohen-Sutherland algorithms to clip the line with end points (70, 20) and (100, 10) against a window whose lower left hand corner at (50, 10) and upper right hand corner at (50, 40).

b) Calculate net transformation metrics for reflection through y = x lines.

9. Write short notes on:

- Flat Panel display
- Illumination model