Computer Science 455
Instructor: R. P. Burton
First Quiz
May 12-13, 2003
Name _________________________________________ Score ____________/45
1. Starting with Sutherland’s landmark work in the early 1960s, and due to a ubiquitous (“universal”) preference for pictures rather than text, computer graphics was accepted almost instantly and used widely.
a. true
b. false
(b)
2. Sutherland’s presentation of flight simulation (using computer graphics) to the Navy was not accepted as practical or appropriate for aircraft carrier flight training.
a. true
b. false
(a)
3. The use of computer graphics for architectural design was
a. limited initially to large structures with lots of modular repetition
b. used initially for the design of individual residences, and then extended to larger and larger structures
c. developed along two parallel tracks: 1) large structures and 2) individual residential structures
(a)
4. Simulators, using principles of physics, are in use today for all of the following EXCEPT
a. small aircraft
b. personal automobiles
c. farm and construction equipment
d. boats
e. (no exceptions here)
(e)
5. With the advent of computer graphics, presentations showing 2, 3, and even 4 variables have become commonplace in the sales and marketing divisions of corporations.
a. true
b. false
(b)
6. Art, including even painterly (“impressionistic”) images can and has been produced using computer graphics systems.
a. true
b. false
(a)
7. Computer graphics has been essential to the presentation of fractals (i.e. without computer graphics, fractals would be largely unknown mathematical monsters).
a. true
b. false
(a)
8. Virtual vehicles can be pushed safely to limits to which their physical counterparts cannot be pushed safely.
a. true
b. false – limits are limits; you can program “reality” and exceed safe limits to the simulated environment
c. false – virtual vehicles have not yet reached the limits of their physical counterparts.
(a)
9. The domain of computer graphics applications (pick the most inclusive, correct answer)
a. is limited to phenomena which are visible in the real world, whether with the unaided eye, the telescope, the microscope, or other viewing device
b. extends beyond visible phenomena to phenomena which can be detected with the other senses
c. includes phenomena which can be detected with the senses and phenomena which can be only hypothesized
(c)
10. “Computer graphics” and “image processing” are
a. synonyms
b. activities which, in a sense, start at opposite ends of a common spectrum
c. unrelated, despite the similarities in the names
(b)
11. Computer graphics is
a. about a half century old
b. about a quarter century old
c. about a decade old
(a)
12. Economically viable commercial computer graphics is about
a. a half century old
b. about a quarter century old
c. about a decade old
(b)
13. A cathode (in a CRT) consists of
a. the connector pins on the end of a CRT
b. an electronic “rifle” that fires electrons at specific positions on a a phosphor-coated screen
c. a source of electrons
d. a mechanism for focusing electrons
e. a mechanism for deflecting electrons
f. a mechanism for limiting the flow of electrons
(c)
14. A moving image which is refreshed 120 times/second can be expected to be twice as realistic as the same moving image refreshed 60 times/second.
a. true
b. false
(b)
15. If the electron gun can be aimed at 2048 positions along a single scan line of a 10” wide screen, then the resolution of the system can be assumed safely to be approximately 205 points/inch.
a. true
b. false
(b)
16. How long does it take for the electron gun to be directed at every point on a calligraphic monitor?
a. one (flicker-free) refresh cycle
b. 1/28th of a second
c. could be as much as a second
(c)
17. How long does it take for the electron gun to be directed at every point on a raster monitor?
a. one (flicker-free) refresh cycle
b. 1/28th of a second
c. could be as much as a second
(a)
18. The most popular contemporary monitor (from the following list) is the
a. beam-penetration CRT
b. shadow-mask CRT
c. direct view storage tube
d. plasma panel
(b)
19. What specific problem did the direct view storage tube solve?
a. frame buffer access
b. weight of the display
c. overlaying the display transparently
d. maintenance of the image on the display
e. (all of the above)
(d)
20. A principal advantage of the plasma panel is
a. the range of colors it is able to present
b. its relatively high resolution
c. its ability to maintain an image without having to redraw the image
d. its relatively fast write and erase times
e. (all of the above)
(c)
21. Laser displays are particularly useful for presentations requiring
a. high resolution
b. realistic colors
c. outdoor settings
d. no selective erasure
e. large screens
(e)
22. What is the source of illumination for a liquid crystal display?
a. zinc sulfide doped with manganese sandwiched between glass plates
b. neon-based gas sandwiched between glass plates
c. light from the surroundings or from an internal source
d. electrons directed toward a phosphor-coated screen
(c)
23. Which of the following does NOT produce/contain at least two separate 2D images (one for each eye)?
a. the varifocal mirror
b. a hologram
c. shuttered glasses
d. colored glasses
e. the (static) stereo box
f. an autostereogram
(a)
24. Which if the following is incapable of producing true, simultaneous 3D output?
a. a rotating LED panel
b. stereolithography
c. a numerically controlled milling machine
d. (all are capable of producing true, simultaneous 3D output)
(a)
25. The Rand Tablet had 1024 vertical wires and 1024 horizontal wires. A wire is identified by its Gray code. How many bits were needed for the Gray code for any particular wire?
a. 10
b. 11
c. 12, because of the unique characteristics of Gray code
(a)
26. In order for an input device (such as a Spaceball) to provide 3D input in a meaningful way, it must be possible to move the Spaceball left/right, forward/backwards, and up/down.
a. true
b. false because other motions such as twist can better communicate up/down
c. false because the Spaceball doesn’t need to actually move
(c)
27. Consider an acoustic tablet and its stylus. Which is more relevant in using the tablet and stylus as a locator?
a. the locus of points a uniform distance from a point (such as the tip of the stylus)
b. the locus of points a uniform distance from a line (such as a strip microphone)
c. Both (a) and (b) are equivalently meaningful in this context.
(a)
28. A 3D acoustic tablet would work with
a. three perpendicular strip microphones
b. strip microphones along three of the four edges of the tablet
c. strip microphones along all four edges of the tablet
d. either (a) or (b)
(a)
29. Touch panels use _______ methods.
a. optical
b. acoustical
c. electrical
d. optical, acoustical, or electrical
(d)
30. The light pen
a. senses light coming from the screen, and hence does not work if no light is coming from the screen
b. deposits light on the screen by using touch panel methodology to determine its position
c. deposits light on the screen by writing a positive charge to a storage grid
d. works only with a vector display
(a)
31. A voice system functions best as a logical ______, as discussed in class.
a. keyboard
b. locator
c. stroke device
d. valuator
e. pick
(e)
32. Pick the best statement:
a. Any of the physical input devices discussed in class can function as any of the logical input devices discussed in class.
b. The set of logical input devices which can be modeled by any of the physical input devices discussed in class is empty.
c. The set of physical input devices discussed in class which can model all of the logical input devices discussed in class is empty.
(a)
33. An “application” user of a graphics package should work in
a. master coordinates
b. world coordinates of the developer’s choosing
c. world coordinates of the “application” user’s choosing
d. normalized device coordinates
e. physical device coordinates
(c)
34. The primary motivation behind graphics software standards is
a. cooperation; the last thing graphics needs is a nonconformist
b. national/international mandate (i.e. to comply with the law)
c. economics
d. historical, since virtually all of early graphics was developed in one place
(c)
35. What are the “jaggies?”
a. the pointy ends of lines drawn with a vector display, attributed to the rise and fall times of the control grid
b. the failure(s) of DDA circles to close, due to the fact that the determinant does not have a value of 1
c. British racing car enthusiasts
d. “stairsteps” on lines and circles
(d)
36. Suppose the first endpoint is at (10,20) and the second endpoint is at (100,200). What is the line length estimate for a simple DDA?
a. less than 100
b. between 100 and 200
c. between 201 and 300
d. between 301 and 400
e. more than 400
(b)
37. Suppose the first endpoint is at (10,20) and the second endpoint is at (100,200). What is the line length estimate for a symmetric DDA?
a. less than 100
b. between 100 and 200
c. between 201 and 300
d. between 301 and 400
e. more than 400
(c)
38. For the preceding question and for efficiency purposes, what should be the value of the first x coordinate used in scan converting the line?
a. 10
b. more than 10, but less than 20
c. more than 20, but less that 100
d. more than 100, but less than 200
e. 200
(b)
39. Suppose the first endpoint is at (10,20) and the second endpoint is at (100,200). What is the line length estimate for a Bresenham line?
a. less than 100
b. between 100 and 200
c. between 201 and 300
d. between 301 and 400
e. more than 400
(b)
40. For a Bresenham circle as discussed in class, which happens first?
a. the determination of the point (xI+1, yI+1)
b. the determination of the next decision parameter, using xI+1 and/or yI+1.
(a)
41. Suppose time t is required to determine the location in the frame buffer of the first point of a DDA/symmetric DDA/Bresenham line. About how much time should be required to determine the location of the next point along the same line?
a. less than t
b. t
c. more than t
d. can’t say in general
(a)
42. What is/are the disadvantage(s) of using the implicit equation of a circle to scan-convert the circle?
a. It’s slow
b. It determines points along the circumference unevenly
c. It may necessitate changing the dependent variable
d. (all of the above)
(d)
43. What is/are the disadvantage(s) of using the polar parametric equation of a circle to scan-convert the circle?
a. It’s slow
b. It determines points along the circumference unevenly
c. It may necessitate changing the dependent variable
d. (all of the above)
(a)
44. In order to determine points around the circumference of a circle whose center is NOT at the origin, points along _____ must be calculated using the implicit equation, polar parametric equation, and/or Bresenham algorithm.
a. the entire circumference
b. half the circumference
c. a quarter of the circumference
d. an eighth of the circumference
e. (it depends on whether the implicit, polar parametric, or Bresenham approach is used)
(d)
45. The same kinds of algorithms used for drawing circles can be adapted to draw ellipses (in standard position, i.e. not rotated).
a. true
b. false
(a)