Computer Science 455
Instructor: R. P. Burton
First Quiz

January 17, 2003

1. Computer graphics is useful in design processes for all of the following reasons EXCEPT
   • it's often less expensive and less time-consuming
   • it can compress or expand simulation time
   • it's often safer
   • it often facilitates tests and evaluations which otherwise would be difficult or impossible
   • (no exceptions here)
   (e)


2. Computer generated animations are used almost exclusively for movies, TV shows, games, and advertisements.
   • true
   • false
   (b)


3. While computer graphics may be applicable to the design process, the actual manufacturing process (even of prototypes) falls outside the scope of computer graphics.
   • true
   • false
   (b)


4. Computer graphics is practical for architectural design of large buildings with repeated modules, but is not yet practical for relatively simple structures such as private residences.
   • true
   • false
   (b)


5. Computers are capable of producing graphs representing ____ apparent dimensions.
   • only two
   • up to three
   • four or more
   (c)


6. Computer graphics is limited to the simulation of phenomena which the eye can observe, meaning that, if the eye (aided or unaided) cannot observe a phenomenon in the physical world, the phenomenon cannot be presented using computer graphics techniques.
   • true
   • false
   (b)


7. For all intents and purposes, "computer graphics" and "image processing" are synonyms.
   • true
   • false
   (b)


8. Pick the better statement:
   • The advent of computer graphics (Sutherland and later) was the impetus for the development of CRT technology.
   • CRT technology was significantly developed prior to the advent of computer graphics.
   (b)


9. At the present time, the minimum refresh rate for a CRT is dictated most strongly by
   • the maximum persistence of screen phosphors
   • the number of pixels that must be refreshed
   • the sampling rate of the human visual system
   (c)


10. Maximum resolution (pixels/inch) is technologically limited most by
    • the capacity of the registers which hold the x and y deflection values
    • the size of the display surface
    • minimum beam size and phosphor graininess
    • processor speed and memory size
    (c)


11. Line drawing commands for a calligraphic monitor were stored in a refresh display file. By cycling through the file without interruption, the image was refreshed continuously. If the file was too large, the image would flicker. If the file was "too small,"
    • that was okay
    • refresh needed to be delayed
    • the user simply refreshed more frequently, further avoiding the potential for flicker
    (b)


12. In a "beam penetration" CRT, what did the beam "penetrate?"
    • a collector
    • a storage grid
    • vertical and horizontal deflection fields
    • multiple layers of phosphor
    (d)


13. A shadow mask CRT typically has thousands and thousands of tiny phosphor dots, each of which can produce red, green, xor (exclusive-or) blue photons.
    • true
    • false
    (a)


14. How many electron guns does a shadow mask CRT have?
    • just one
    • three
    • literally thousands
    (b)


15. What particular problem did the direct view storage tube solve?
    • the memory capacity problem
    • the refresh problem
    • the monochrome CRT problem
    (b)


16. The original plasma panels were monochrome (orange) and had resolutions of roughly 60 pixels/inch. Over the first two decades of their existence and use,
    • they were still monochrome and still had low resolution
    • they were able to present a spectrum of colors comparable to a CRT with a resolution slightly superior to the conventional CRT
    • they were able to present a spectrum of colors superior to the CRT with a resolution significantly superior to the conventional CRT, leading ultimately to commonplace HDTVs.
    (a)


17. Which of the following represent(s) true 3D output, as discussed in class?
    • rotating LED panels
    • varifocal mirrors
    • holograms
    • autostereograms
    • biodal projections and shuttered projections
    • (all of the above)
    • (none of the above)
    (g)


18. In order for a 3D input device such as a spaceball to be functional, it must move when pushed or pulled.
    • true
    • false
    (b)


19. In order for an input device such as a mouse to be functional, the mouse must respond (more or less linearly) when the hand (holding the mouse) is moved. I.e. if the hand moves forward, the mouse must sense the forward movement and respond more or less linearly. Prior to the advent of surfaces like the mouse pad, surface slippage rendered a mouse, for the most part, nonfunctional.
    • true
    • false
    (b)


20. Two pieces of information representing the distances of a signal from two perpendicular strip microphones (indicated by the delays between the occurrence of the signal and the time it was sensed by each microphone), are sufficient to determine a unique point in three-dimensional space at which the signal occurred.
    • true
    • false
    (b)


21. The technology behind touch panels is
    • optical
    • electrical
    • acoustical
    • (all of the above)
    • (none of the above)
    (d)


22. Light pens write on the screen by
    • emitting light
    • sensing light
    • interrupting light (beams)
    (b)


23. "Guns," such as those used in the game "Duck Hunt," are able to "hit" screen targets by
    • emitting light
    • sensing light
    • interrupting light (beams)
    (b)


24. Any of the logical input devices discussed in class can by modeled by any of the physical input devices discussed in class, and vice versa.
    • true
    • false
    (a)


25. A "pen" used in a mechanical plotter could be any of the following EXCEPT
    • a felt-tipped pen
    • a ballpoint pen with no ink in it
    • a laser
    • a carbide-tipped scribe
    • an old fashioned quill
    • (no exceptions here)
    (f)


26. Which of the following coordinates are used for computer graphics?
    • master coordinates
    • world coordinates
    • normalized coordinates
    • physical device coordinates
    • (all of the above)
    (e)


27. What is the purpose of graphics standards?
    • To keep "schlock" from the market place.
    • To limit the use of graphics techniques for obscene purposes
    • To facilitate portability
    • To offer support for the movement toward the metric system
    (c)


28. The point-plotting mentality of the 1960s is
    • of historical interest only
    • sometimes (but rarely) extensible to current techniques
    • relevant for today's graphics
    (c)


29. Who/What are the "jaggies?"
    • a British rock group popular at the same time graphics was really getting off the ground
    • jitters which occur as the beam in a CRT is deflected to its extremes
    • unwanted distortions which occur when shadowmask bands in a Trinitron CRT accumulate residual magnetism
    • the "stairstep" aspects of discretized images
    (d)