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TEST 2 - CS458 
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Instructor Dr P Juell                   NAME_______________________ 
CLOSED BOOK                                        Oct 30, 1996
100 points         
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1. (20)
A cone is centered at (3,2,1).  Specify the string of transformations
(T(x,y,z),S(x,y,z),Rx(a),Ry(a),Rz(a)) to turn this upside-down at this point
in space.  Then write the string of matrices corresponding to the 
transformations.  Do NOT multiply the matrices.

If this is too hard, for 15 points do:
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A triangle is specified with a center point at (2,3).
Turn the triangle 90 degree to the right ( _     |  )
around the center point.
Specify the transformations and matrices to perform this transformation.

Transformations (in book order):


Matrices (in book order):
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2. (10)
There are various uses of pointing devices.
List the types of uses of the devices in the following.
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)

3. (10)
What happens if you apply different transformational matrixes to
different parts of a single polygonal object?
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4. (10)
What is the purpose of "intensity cueing" in a wire frame display?
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What is one technique that could be used for "intensity cueing"?
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5. (10)
Why would you want a curve with type 2 continuity rather than just 1 continuity?
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What could be different between the two curves?
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6. (10)
A line has end points coded as 1001 and 0101 in the Cohen and Sutherland 
line clipping procedure.  What does this tell the procedure it should
do with the line?
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7. (10)
What is a good reason for needing line or polygon clipping routines?
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8. (20)
You are supplying computer graphic images for a horror movie and the 
director decides she wants curves  GUARANTEED NOT to have
type 2 continuity.
(She says this will make sick looking skin).
How could you do this?
Remember, you needed to GUARANTEE the curve does not have type 2 continuity,
not just that it might not.
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HINT: In Zero order (parametric) continuity, the curves meet.
Type 1 continuity tangents are equal at the joining point.
Type 2 continuity both first and second derivatives are the same
at the joining point.