TEST 3 CS458

Instructor Dr P Juell    NAID______________________ NAME__________________________

100 points, closed book                                  Dec. 5, 2002

(10) What is the relationship between the RGB model (for a particular monitor) and the CIE model?

(20) Specify True or False

_________ All points (other than black) in a color cube based on 
          a visible red, green and blue are visible.

_________ If there are NO curvied surfaces (and none wanted)
          we do not need either Gouraud or Phong shading

_________ Dithering will allow you to approximate gray scale image
          on a printer that can only display black or white dots.

_________ You would expect that diffuse shading of a sphere from a
          single light source with a very few gray levels would
          cause a viewer to see Mach banding.

_________ For a single object fully in the view window, meeting the
          requirements for a convex polyhedron, simple back removable 
          is sufficient for hidden surface removal.

(10) Give an environment (image) where using radiosity without ray tracing would produce a realistic looking image.
given an environment (image) where using ray tracing without radiosity would produce a realistic looking image.
(10) What do you get if you use Phong shading with a cube?
(20) In HSV (0,1,1) is Red. Specify HSV and RGB values for the following colors:

color ( H, S, V) ( R, G, B)
pink
_
white
_
black
_
gray
_
dark red
_

(30) For each column, specify a ranking from most appropriate (1) for that category to least appropriate (7). Note, there is at least one case where you can not tell the difference between two or more items. If that is the case, they should have the same rank number.

lowest computational requirement image quality good looking transparent items good looking shadows simple algorithm scales well as objects increase
scan line visible surface
painters algorithm
z-buffer
ray tracing
ray tracing with radioisty
Gouraud shading
Phong shading

color	( H, S, V)	( R, G, B)
pink _
white _
black _
gray _
dark red _

	lowest computational requirement	image quality	good looking transparent items	good looking shadows	simple algorithm	scales well as objects increase
scan line visible surface
painters algorithm
z-buffer
ray tracing
ray tracing with radioisty
Gouraud shading
Phong shading