Computer Science 102
                               Quiz N      Name ______________________


1. In the approach to anti-aliasing that was discussed in class,
   the number of rays traced per pixel

   a. is still one ray per pixel     b. is some constant number > 1

   c. is a random number of rays


2. To perform antialiasing ray direction should be randomized.  In the
   method proposed in class this was done by adding a random offset to

   a.  The x, y components           b.  The (x, y) pixel coordinates
       dir.x and dir.y of the            of the point at which the ray
       direction vector                  was fired


   c. The (x,y) world coordinates
      of the point at which the
      ray was fired.

3. The value to be added in the randomization should be in the range:
   procedure should be

   a. (0, 1)                         b. (-0.5, 0.5)

   c. (0, 0x7ffffff)

4. Suppose an image of 1000 x 1000 pixels is created with 20 antialised
   samples per pixel and an average of 5 specular bounces per ray.
   The total number of calls to ray_trace() is closest to:

    a. 1,000,000                      b. 50,000,000

    c. 20,000,000                     d. 100,000,000

5.  Now suppose that one of the objects in the scene is made partially
    transparent.  The number of ADDITIONAL calls to ray_trace() that
    this will produce is closest to:

    a. 1,000,000                      b. 20,000,000

    c. the number of rays that        d. the number of rays that
       are fired from the viewpoint      are fired from the viewpoint
       and hit the transparent           and hit the transparent
       object                            object plus the number that
                                         bounce into the transparent
                                         object.