# JNTU papers B -Tech Examinations, IIIrd sem Computer graphics, Aug/Sep 2008

JNTU III B.Tech Supplimentary Examinations, Aug/Sep 2008

COMPUTER GRAPHICS

(Computer Science & Engineering)

SET-III

1. (a) List and explain the applications of Computer Graphics.

(b) With a neat cross- sectional view explain the functioning of CRT devices.

2. (a) Explain the DDA scan conversion algorithm for generating the points on line

segment, when two end-points are given as input.

(b) Digitize the line with end-points (20,10) and (30,18) using DDA algorithm.

3. (a) Prove that a uniform scaling (sx = sy) and a rotation form a commutative pair

of operations, but that, in general, scaling and rotation are not commutative.

(b) Derive the transformation matrix for rotation about origin.

4. (a) What are the stages involved in Window-to-viewport coordinate transformation. Explain about each stage.

(b) What is the procedure followed in point clipping with respect to a rectangular

window.

5. (a) Explain about different representation of polygon meshes in surface modeling.

(b) What are the characteristics of parametric cubic curves? What are its advantages?

6. Derive the transformation matrix for aligning an arbitrary vector V=a1I + b1J + C1K

with another arbitrary vector N= a2I + b2J + C3K.

7. (a) Distinguish between object-space and image space methods of visible surface

detection algorithms. Give examples for each.

(b) Given points P (1, 2, 0), P (3, 6, 20) P (2, 4, 6) and a view point C (0, 0, -10),

determine which points obscure the others when viewed from C.

8. (a) Explain how the linear interpolation is implemented when the key-frame po-

sitions of an object are given.

(b) Describe linear list notation of animation languages.