TEST 2 CS458

Instructor Dr P Juell    NAID______________________ NAME__________________________

100 points, closed book                                  Oct. 29, 2002
  1. (10) Give an example where contour lines would be useful.
    Give an example where contour lines would be of limited use.
  2. (10) Give a parametric equation, in terms of alpha, of the line equation from (1,2) to (2,4).
  3. (10) Give an example of something that would be easy to build using CSG. Also, why would it be easy?
    Give an example of something that would NOT be easy to build using CSG. Also, why would it not be easy?
  4. (10) The attached page has a surface weather map for Oct 27,2002. What is the difference in weather at Grand Forks (GFK) and Fargo (FAR) shown on the map?
  5. (10) Draw approximately the shape you would get with a Bezier curve for the following points: (0,0), (1,1), (0,2), (-1,2), (0,0). Be sure to show the points.
  6. (10) Give two strong points in using fractals in synthesizing images.
  7. (10) You you are working with a 3D image generation system such as VTK. Describe an experiment that would allow you to determine if the system uses a left hand coordinate system. (Just telling about the final test with your hand is not enough).
  8. (15) Circle the best answer for each:

    True or False: the normal cone we use is also a ruled surface cone.

    True or False: false coloring is a way to code a dimension of data into graduations of colors.

    True or False: There is no way to display more than 3 dimensions of data on a flat monitor screen.

    True or False: Fractals are a convenient way to build realistic looking items such clouds and mountains.

    True or False: The curve at a point in a Bezier curve is effected by the location of a control point 6 control points away.

  9. (15) In three space the picture element is a voxel rather than the 2D image pixel. Assume you want to store a 3D black and white image. Three methods to store it are (1) to assign a bit per voxel, (2) save the x,y,z address for each voxel that is on, or (3) use octree encoding. Specify an image type or example for each of the three storage techniques where that technique would be better than the other two techniques.

    (1) bit per voxel
    (2) x,y,z address
    (3) octree

    region surface weather map

    close up of ND detail of the Red River Valey