BCA Semester 5 – Computer Graphics and Animation – Unit 3: Clipping (7Hrs)

Explain Cohen Sutherland line clipping algorithm. Let ABCD be the rectangular window with A(20,20), B(90,20), C(90,70) and D(20,70). Use Cohen Sutherland algorithm to find the region codes and ellipse the lines with end point P(10,30) and Q(80,80)

Explain Sutherland-Hodgeman Polygon Clipping algorithm and trace it to clip a polygon with end points P(10, 30), Q(25, 35), R(35, 50), S(60, 30), T(45, 28), U(40, 15) against a window whose lower left corner is at (15, 25) and upper right corner is at (50, 40).

How region codes are used in Cohen-Sutherland algorithm to clip the line segments? Find the clipping coordinates for lines PQ and RS with P(20, 5), Q(40, 30) and R(20, 30), S(80, 60) against the window with left upper corner(10, 50) and right lower corner(50, 10).

What is polygon clipping? Explain Sutherland Hodgman algorithm for polygon clipping.