FINAL - CS458 Fall 2002

FINAL - CS458 

Instructor Dr P Juell                         NAME_______________________ 
CLOSED BOOK                                        Dec 18, 2002 12:30am-2:30pm
200 points
There are 260 points presented on this test. Work 200 points of problems. The first 200 points attempted will be graded. If a problem is not to be graded, put a line through it. If you do the last problem, you need to work all of it. You can not clain half of a problem attemped.

  1. (10) Pick two of the following ( ray tracing, radiosity, Gouraurd shading, Phong shading, scan line visible surface, painters algorithm, z-buffer) that are related. Specify the two chosen. Then contrast the two based on computational cost and image quality.
  2. (10) Give a parametric equation, in terms of alpha, of the line equation from (1,2) to (2,4).
  3. (10) Draw a station reporting weather glyph for the following information. A north wind at 15 knots. The current temperature is 30 and the dew point is 15. There is a 50% cloud cover.
  4. (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.
  5. (10) What are two major reasons we use fractals to synthesize objects when we want natural appearing items?
  6. (10) The Cohen-Sutherland line clipping operation does an operation on two string of bits. What is the operation, and what does the value tell you to do.
  7. (10) Most graphic systems use a viewing pipeline. Identify two stages in the the pipeline the type of processing that occurs in that stage.
  8. (10) Bresenham's line algorithm uses the sign of the parametric value to chose between two options. What are the two options?
  9. (10) You have a command to create a triangle (TRI) at the origin, the translation (T(x,y)), scale (S(x,y)) and rotation (R(A)) commands. Specify a sequence of commands to create the following figure. The small triangle is the size created by TRI and the other is doubled in size. You also need to show what the TRI command does. 
                   (10,6)
|              /\
|           __/__\__
|           \      /
|            \    /
|             \  /
|______________\/_______
               (10,0)
  10. (10) Two ways to store information are in raster and polyline forms. Present a good reason that information such as a outline of the US would be better stored in a polygon rather than a raster form.
    Present a good reason for using raster over a polygon.
  11. (10) What is the normal assumption about spatial relationships that makes contour lines meaningful? (In other terms, when might you use contour lines?)
  12. (10) There are various uses of pointing devices. Give the technical terms for the following uses. First (a) the routine is selected from a menu, then (b) the person signs their name, finally (c) the user selects which line is the start of their last name.

    (a)

    (b)

    (c)

  13. (10) Give a major strength of VTK and a major weakness in the context of our class.
  14. (10) When animation is done by hand, they typically use loops. Why do they use "loops" or "film loops"?
  15. (10) For each of the following circle the item in the list that goes with the first item:

    Bresenham line algorithm: vector display, raster display

    odd-even rule: items with boundaries, vector based data

    dithering: anitalizaling, line drawing

    extra item per pixal: octree, z-buffer

    prospective transform: 3D viewing, shading

  16. (10) Those trying to produce realistic images (RI) and those trying to visualize data (VD) have rather different concerns in creating an image. Why would the VD group use pseudo-color and why would RI group normally not use pseudo-color?
  17. (10) What are the reasons why a line in a model may have only part of the line displayed in a window?
  18. (10) How might you get good looking specular highlights on dull wood, semi-shiny skin and shiny eyes. The easiest way to answer this is to give the important part of the formula and approximate values.
  19. Constructive Solid-Geometry (CSG), Blobby Objects, Spline Representations and Sweep Representations are four ways to define solid objects.
    For each, specify an object that would be good to build by that particular technique.
  20. (10) Give an example of a ruled surface.
  21. (10) What do the front and back faces of a viewing volume do for us?
  22. (10) In the odd-even rule for area filling, what is the relationship between inside, and the number of edges crossed.
  23. (10) Why might a rendering program treat a glass cube differently from a glass window pane? Also specify what type of technique that would be used with each.
  24. (10) What are two different reasons we might need line clipping routines?
  25. (20) For the following the color notation, the three values and the color are specified. For example in HSV (0,1,1) is Red. What are the following colors: