CSC461 Computer Graphics I

(Fall 2005) 

Midterm Examination 1

1. (15 points, 3 points each) Briefly explain

1) The field of view of a pin-hole camera and the depth of field

2) Aspect ratio and viewport

3) Hidden-surface removal 

4) Display lists

5) Three rendering modes

2. (15 points, 3 points each) Briefly explain the following OpenGL function calls.

1) glutMainLoop() and glutPostRedisplay( )

2) glutFlush() and glutSwap()

3) glOrtho(-2.0, 2.0, 0.0, 2.0, -1.0, 1.0)

4) gluLookAt(2.0, 2.0, 2.0, 1.0, 1.0, 1.0,   1.0, 0.0, 0.0);

5) glShadeModel(GL_FLAT), glEnable(GL_DEPTH_TEST), and glClear(GL_COLOR_BUFFER_BIT)

3. (10 points) An aligned rectangle can be described in different ways. One of these possibilities is to specify its center point, height, and width. Write a display callback to draw a rectangle defined in this way. You can use global variables to pass parameters.

4.  (10 points) There is a rotating six-edge polygon centering at a location V0=(x0, y0) with equal-length edges. At a moment, the slope of the line V0-V1 is a. Assuming that V0 is given, and the distance between V0 and any vertex is r, find the coordinates of all vertices V1 through V6.