Sample Mid-Term Exam
CMSC 427, Fall 2001
Time Limit: 75 minutes, Maximum Marks: 60
Open book, open notes
Name:
UMD Id:
Note: This exam has three pages. Please make sure you have all of them .
If the meaning of a question is doubtful, state a meaningful, non-trivial assumption and
proceed.
Advice: To maximize partial credit, divide your time as per the minutes shown. Point value
of each question equals its recommended time value in minutes.
Important: This is just a sample midterm. The real midterm will have more
questions to ensure a better coverage of topics that we have covered in the class.
This paper has questions worth 45 minutes instead of the target 60 minutes.
The general level of difficulty will be approximately what you see here.
Q.1 [6×5 = 30 minutes]
(i) List two components of the graphics pipeline that are typically carried out in fixed-point
arithmetic and two that are typically computed in floating-point arithmetic.
(ii) Interactivity in 3D graphics has been defined as 20 - 30 frames per second. Where does
this number come from? (a) CRT and LCD refresh rate frequencies, (b) Rate at which
graphics cards can display 1 million triangles per frame, (c) Both of the above, (d) None of
the above.
(iii) Consider a line segment that starts from (0,1) and ends at (2,4). Its equation is given
by 3x−2y+ 2 = 0. I decide to verify the Bresenham’s line drawing algorithm on this
line. Using the slides in Lecture 3, I set F(x, y) = ax +by +c= 3x−2y+ 2 and initialize
D= 2F(0,1) + 2a+b= 4. Since D > 0, I select the East pixel and set D=D+ 6 = 10.
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