# 2004 Anna University Chennai B E Computer Science CS 239 INTERACTIVE COMPUTER GRAPHICS Question paper

** University Question Papers **

**
**2004 Anna University Chennai B E Computer Science CS 239 INTERACTIVE COMPUTER GRAPHICS Question paper

B.E/B.Tech.DEGREE EXAMINATION,APRIL/MAY 2004.

Fourth Semester

Computer Science and Engineering

CS 239- INTERACTIVE COMPUTER GRAPHICS

Time: Three hours Maximum: 100 marks

Answer ALL questions

PART A-(10*2=20 marks)

1. Briefly explain about refreshing CRT.

2. What is frame buffer?What are Bitmap and Fixmap?

3. Explain briefly the advantages of storing color codes in a lookup table.

4. What is need of antialiasing?

5. What is viewing and windowing?

6. Give two examples of wireframe displays an design applications.

7. Explain briefly the two categories of visible-surface detection algorithms.

8. What possible relationships a surface can have with a specified area boundary?

9. State the uses of chromaticity diagram.

10. What is realism rendering?

PART B-(5*16=80 marks)

11. (i) Explain midpoint circle algorithm. Given a circle radius r=10,

demonstrate the midpoint circle algorithm by determining positions

along the circle octant in the first quadrant from x=10 to x=y. (12)

(ii) Write about the following i/o device

Touch Panels. (4)

12. (a) (i) Define an efficient polygon representation for a cylinder. Justify

your choice of representation. (3)

(ii) Determine the Bezier blending functions for five control points. Plot

each function and label the maximum and minimum values. (13)

Or

(b) Discuss model representations that would be appropriate for several

distinctly different kinds of systems. Also discuss how graphical

representations might be implemented for each systems. (16)

13. (a) The triangle position is A(1,1),B(3,5) and C(2,2), translate the given

triangle with respect to its centroid with A in the centroid position and

rotate it by an angle 30°.after shrinking the object half the size. (16)

Or

(b) Explain in detail about the 3D rotation including all cases. (16)

14. (a) Explain the following visible surface detection methods:

(i) Area-Subdivision algorithm. (8)

(ii) Scan-Line algorithm. (8)

Or

(b) (i) Discuss how wireframe displays might be generated with the

various visible surface detection methods. (4)

(ii) What is ray casting? Explain about Basic Ray-Tracing algorithm. (12)

15. (a) (i) Explain the color models defined with primary colors. (8)

(ii) Explain the color models based on specification of luminance and

purity values. (8)

Or

(b) (i) Explain the techniques for antialiasing in ray tracing. (6)

(ii) Explain any two polygon -rendering methods in detail. (10)