# Computer Graphics December 2010

Note: Answer any FIVE full questions.

1 a. Explain the conceptual framework for interactive graphics, with a neat block diagram.

b. Explain the various representative uses of computer graphics, in detail.     (10

2 a. Briefly explain the Bresenham’s midpoint line scan conversion algorithm. Derive the expressions for decision variables.

b. Briefly explain the basic methods used for drawing thick primitives.

3 a. Give the Cohen-Sutherland line clipping algorithm (psedocode).

b. Briefly explain and give the Sutherland-Hodgeman polygon clipping algorithm (psedocode).

4 a. Explain the steps involved in transformation from a world co-ordinate window to screen co-ordinate viewport. Also get the composite transformation matrix.

b. Find the transformation matrix, that transforms the given square A B C D to half its size, with centre still remaining at the same position. The co-ordinates of square axe A (1, 1), B(3, 1), C(3,3) and D(l, 3)and centre at (2, 2). Also find the resultant co-ordinates of the square.

5 a. Write the homogeneous co-ordinate transformation matrices for the three basic 3D transformations.

b. Give the classification of planar geometric projections. With neat sketches, explain the orthographic and oblique parallel projections.

6 a. Briefly explain the three common styles for user-computer interfaces,

b. List the properties of B-spline curves.

7  a. Explain the Z-buffer algorithm for the removal of hidden surfaces, with a psedocode.

b.  Explain the Wamock’s area subdivision algorithm.

8 Write short notes on :

a.   Octrees

b.  Rubber band construction technique

c.   Character generation methods

d.  Fractal geometry methods.