Computer Graphic (CG) Semester 4 (Revised Course) (3 Hours) May 2013

Computer Graphic (CG) Semester 4 (Revised Course) (3 Hours) May 2013
GS-7110 [Total Marks : 100]
N.B:	(1)	Questions no 1 is compulsory.
	(2)	Attempt any four out of remaining questions.
	(3)	Assume suitable data if necessary and justify the same.
1.	(a)	Explain the method to draw a thick line using Bresenham's algorithm.	05
	(b)	Differentiate between Image space and Object space.	05
	(c)	What is aliasing? Explain some antialiasing techniques.	05
	(d)	Derive the transformation matrix to magnify the triangle A (0, 0), B(1, 2), C(3, 2) to twice its size so that the point C(3, 2) remain fixed.	05
2.	(a)	Explain Liang-Barsky line clipping algorithm. Apply the algorithm to the line with co-ordinates (30, 60) and (60, 25) against the window (xmin' ymin = (10, 10) and (xmax. ymax) = (50, 50).	10
	(b)	Explain parallel and perspective projections. Perform a perspective projection of the unit cube when the center of projection is at xc = 10 yc = 10 on to z = 0 plane.	10
3.	(a)	Derive the composite transformation matrix for reflection of an object about a line y=mx + c. Apply the derived matrix for the object A(4, 2) B(5, 3) C(6, 2) D(7, 1) on to the line y = 2x.	10
	(b)	Derive the midpoint algorithm for ellipse generation.	10
4.	(a)	Explain weiber-Atherton algorithm for polygon clipping. What are its advantages over other polygon clipping algorithms?	10
	(b)	Explain the different raster techniques and the transformation associated with it.	10
5.	(a)	Explain painter's algorithm.	10
	(b)	Explain Gourand and Phong shading with their advantages and disadvantages.	10
6.	(a)	Explain computer assisted animation and frame- by- frame animation concepts.	10
	(b)	Explain scan line fill algorithm with some suitable examples.	10
7.	(a)	Explain RGB and CMY colar models.	10
	(b)	State the properties of Bezier curves. How can a Bezier surface be generated from a Bezier curve?