Computer Science 455

Instructor: R. P. Burton

Seventh Quiz

December 8-9, 2003

 

Name _________________________________________    Score ____________/33

 

1.                  Fractal geometry (including “fractal” pictures) is about as old as

a.                   you

b.                  your parents

c.                   the State of Utah (statehood was granted in 1896)

d.                  the Roman empire

e.                   Moses / Ramses

 

(a)

 

2.                  Fractals are of interest

a.                   for producing artificial but realistic images

b.                  in science and engineering

c.                   in both (a) and (b)

 

(c)

 

3.                  What is the length of the perimeter of the von Koch snowflake (that started out as an equilateral triangle with sides of length 1)?

a.                   3

b.                  more than 3 but less than 4

c.                   something less than 6

d.                  more than a billion

 

(d)

 

4.                  You have a canoe (standard length: 16.5’) and your friend has a yardstick (standard length 3’).  Each of you wants to measure the length of the shoreline of Lake Powell by flipping your measuring instrument (the canoe or the yardstick) end over end until you have worked your way around the lake and back to the starting point.  Pick the best statement:

a.                   the length of the shoreline measured with the canoe will be dramatically less than the length of the shoreline measured with the yardstick

b.                  the length of the shoreline measured with the yardstick will be dramatically less than the length of the shoreline measured with the canoe

c.                   the length of the shoreline measured with the canoe will be roughly the same as the length of the shoreline measured with the yardstick

 

(a)

 

5.                  Fractals (i.e. pictures) presented in computer graphics books are all forgeries rather than true fractals.

a.                   true

b.                  false

 

(a)

 

6.                  Why are fractal curves often generated with functions in the complex plane?

a.                   because fractals can exist only in the complex plane

b.                  it would be impossible to present infinite detail without using the complex plane

c.                   to separate the “x” component from the “y” component

d.                  (all of the above)

 

(c)

 

7.                  Which points in the Mandelbrot set correspond to a Julia set?

a.                   all of them

b.                  all of the discrete, integer positions

c.                   the points around the perimeter

d.                  none of them; the two sets are distinct

 

(a)

 

8.                  Which of the following should NOT be done with random “midpoint” displacement to produce plausible results?

a.                   correlate the likelihood of selection of a “midpoint” with proximity to the actual midpoint of the line

b.                  correlate the amount of displacement with the length of the line

c.                   have the average displacement be zero

d.                  (all should be done)

 

(d)

 

9.                  What is the fractal dimension of the von Koch snowflake curve?

a.                   1

b.                  between 1 and 2

c.                   2

d.                  between 2 and 3

e.                   3

f.                    infinite

 

(b)

 

10.              The con von Koch snowflake curve exhibits _______ self-similarity

a.                   exact

b.                  statistical

 

(a)

 

11.              Fractally distributed craters suggests

a.                   more little craters than big ones

b.                  about the same number of each size of crater

c.                   more big graters craters than little ones

 

(a)

 

12.              Suppose you begin with a sphere which you divide into hemispheres by cutting in a random direction, subsequently displacing the hemispheres relative to one another.  If you take the resulting shape and repeat the process several thousand times

a.                   areas of common height will be distributed randomly across the resulting shape

b.                  areas of common height will tend to cluster together

 

(b)

 

13.              Precipitation falling along the Wasatch Front in the form of snow tends to

a.                   be randomly distributed throughout the winter months

b.                  form “clusters” where absence of precipitation portents more absence, and occurrence of precipitation portents similar precipitation

 

(b)

 

14.              If you were using fractal techniques to generate a mountain that looks like a mountain in the Canadian Rockies, given an initial sketch consisting of 10 or 20 polygonal faces,  you should iterate (using the output of one iteration as the input to the next iteration) until

a.                   none of the resulting polygonal faces are greater than pixel size

b.                  all of the resulting polygon faces are less than pixel size, averaging for each pixel to avoid aliases

c.                   the polygons are small enough , which may well be substantially larger than pixel size

 

(c)

 

15.              The cosine of x approaches 0.739 under iteration when x is input initially in radians.  This is an example of a(n) _______ orbit.

a.                   stable

b.                  unstable

 

(a)

 

16.              If you wanted to produce a filled-in Julia set, you would iterate

a.                   every point in a 2D array which encloses the Julia set

b.                  until you landed on the Julia set, after which an additional 10,000 iterations would be sufficient for graphical purposes

 

(a)

 

17.              Julia sets are of the form f(z) = z 2 + c.  What is c?

a.                   some constant

b.                  any point on the perimeter of the Julia set

c.                   a point in the complex plane (of the form x + iy)

 

(a)

 

18.              Given one point on a Julia set, how would you find another?

a.                   by adding “c” to the point

b.                  by squaring the point

c.                   by squaring the point and then adding “c”

 

(c)

 

19.              Suppose you use color (in conjunction with a Julia set) to indicating the (finite) number of iterations in an orbit before escape.  How many of the colored regions are actually in the Julia set?

a.                   none

b.                  one

c.                   all

 

(a)

 

20.              Traditionally, the introduction of technology into the arts has been ____ by the arts community.

a.                   welcomed with enthusiasm

b.                  viewed with indifference

c.                   resisted

 

(c)

 

21.              Unless it moves it doesn’t qualify as “animated,” or even “computer animated.”

a.                   true

b.                  false

 

(b[JAG1]  )

 

22.1. Generally, the animation _____ the sound track.

a. precedes

b.a. is done simultaneously with

c.a. follows

 

(c)

 

22.              Which is most likely to be implemented with translation?

a.                   pan

b.                  track

c.                   tilt

d.                  fade

e.                   (none of the above)

 

(b)

 

23.              Interpolation of each pixel from zero intensity to actual intensity represents a

a.                   fade in

b.                  fade out

c.                   cross dissolve

d.                  wipe

 

(a)

 

24.              The first animation was done around the time of

a.                   the Revolutionary War (1776)

b.                  the establishment of the Church (1830)

c.                   Utah Statehood (1896)

d.                  The Roaring Twenties (1920)

 

(b)

 

25.              Animation, for the most part, is limited to children’s cartoons (which adults sometimes watch, too).

a.                   true

b.                  false

 

(b)

 

26.              Which of the following animation activities is likely least interesting or stimulating?

a.                   producing key frames

b.                  producing bar or route sheets

c.                   in-betweening

 

(c)

 

27.              The state-of –the-art of computer animation includes actors with their own animation.

a.                   true

b.                  false

 

(a)

 

28.              What is the most general significant difference between computer-assisted and modeled animation?

a.                   none; they are synonyms

b.                  computer-assisted animation is “flat;” modeled animation is “3D.”

c.                   in-betweening is characteristic of modeled animation; 3D motion programming is characteristic of  computer-assisted animation

 

(b)

 

29.              In frame buffer animation (at least the illusion of) animation is achieved without changing the contents of the frame buffer.

a.                   true

b.                  false

 

(a)

 

30.              In order for one geometric shape to be “morphed” into another geometric shape, the ______ of the two shapes generally must be made to match.

a.                   geometry

b.                  topology

c.                   geometry and topology

 

(b)

 

31.              A single two-dimensional plot (with x and y axes) at most can be made to show

a.                   x and y positions occupied by a shape moving in the plane

b.                  x and y positions occupied by a shape moving on the plane, AND the times at which those positions were occupied

 

(b)

 

32.              How is the motion of an arm determined (for animation purposes)?

a.                   by measuring the positions of points defining the arm at different points in time

b.                  by modeling the bones, muscles, tendons, skin, etc.

c.                   by either (a) or (b), or by a combination

 

(c)


 [JAG1] Referring to the deleted question below, doesn’t this depend a great deal on what kind of animation you’re doing?  If you need to match some sound, like lip movements to speech, you do the sound first, but if you’ve got a visual that you want to add sound effects to, like an action sequence, the other  way around works.  If you’re doing a simulation, both would be generated together, no?

>

 [JAG1] Referring to the deleted question below, doesn’t this depend a great deal on what kind of animation you’re doing?  If you need to match some sound, like lip movements to speech, you do the sound first, but if you’ve got a visual that you want to add sound effects to, like an action sequence, the other  way around works.  If you’re doing a simulation, both would be generated together, no?