## Computer Graphics & Virtual Reality - May 2016

### Information Technology (Semester 5)

TOTAL MARKS: 80

TOTAL TIME: 3 HOURS
(1) Question 1 is compulsory.

(2) Attempt any **three** from the remaining questions.

(3) Assume data if required.

(4) Figures to the right indicate full marks.
**1(a)** Differentiate between Raster scan display and Random scan display.(5 marks)
**1(b)** Prove that two successive rotation transformations are additive(5 marks)
**1(c)** Show that the transformation matrix for a reflection about a line y=x is equivalent to reflection to x-axis followed by counter clockwise rotation of 90°(5 marks)
**1(d)** Explain 3D trackers & enumerate some important trackers characteristics(5 marks)
**2(a)** Specify highlights and drawbacks of Bezier curve. Construct the bezier curve of order three with control P1(0,0), P2(1,3), P3(4,2) and P4(2,1). Generate at least five points on the curve.(10 marks)
**2(b)** Write DDA Line drawing Algorithm Compare DDA with Bresenham's Line drawing Algorithm. Calculate the pixel co-ordinates of line Abusing DDA Algorithm 1 where A=(0,0) and B=(4,6).(10 marks)
**3(a)** Let ABCD be the rectangular window with A (20,20), B(90,20), C(90,70) and D(20,70). Find region codes for endpoints and use Cohen Sutherland algorithm to clip hte lines

P1 P2 with P1(10,30), P2(80,90)(10 marks)
**3(b)** With respect to 3D transformation, describe the steps to be-carried out when an object isto be rotated about an arbitarary axis. Specify all the required matrices. State your assumptions clearly.(10 marks)
**4(a)** Explain Flood Fill Algorithm for 4 connected and 8 connected. What are its advantages over Boundary Fill Algorithm.(10 marks)
**4(b)** Explain an algorithm which uses parametric equation of line clipping. Using same algorithm find the line segment A(10, 10) and B(70, 40) after it is clipped against the window of two vertices (20, 20) and (40,50).(10 marks)
**5(a)** Consider a triangle ABD whose coordinates are A(10, 20) B(30, 40)and 8C(50, 20). Perform the following transformations (Specify the matrices that are used)

(i) Translate the given by 3 units in X direction and -2 units in Y direction.

(ii) Rotate the given triangle by 30

(iii) Reflect the given triangle about X=Y

(iv) Scale the given uniformly by 2 units..(10 marks)
**5(b)** What is the significance of modeling in virtual reality? Explain any modeling technique used in virtual reality.(10 marks)

### Write a short note on (Any five)

**6(a)** Homogeneous Coordinates.(5 marks)
**6(b)** Text Clipping(5 marks)
**6(c)** Fractals(5 marks)
**6(d)** B-spline curve(5 marks)
**6(e)** Morphing and warping(5 marks)