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edu/~copyrght/image/solstice/sum99/lum.gif.
Shows change in the resulting luminos-
ity as one moves along the z-axis. Derived from Netscape 7.2. Source: Arlinghaus, S. L.
and W. C. Arlinghaus. 1999. Animaps III: Color Straws, Color Voxels, and Color Ramps.
Solstice: An Electronic Journal of Geography and Mathematics. Volume X. No. 1. Ann
Arbor: Institute of Mathematical Geography. Source of base image: Netscape software.
http://www-personal.umich.edu/%7Ecopyrght/image/solstice/sum99/animaps3.html.
of the cube) at height 120 (we invite the reader to try it, using pencil and
paper). Fix lines at 180 within that plane: One with hue
=
180 and one with
saturation
=
180. These two lines trace the paths of the crosshairs, respec-
tively, in
Figures 4.2
and
4.3
.
What the cube approach also shows clearly is
that there is really a set of voxels (volume pixels) making up the cube: There
are 256 straws available for each of the three variables. Since 256
=
2
8
, there
are therefore 2
8
* 2
8
* 2
8
=
2
24
=
16,777,216 voxels within the color cube (note
the reliance on discrete mathematics and discrete structuring of a normally
continuous object).
The notion of looking only at voxel subsets within a single plane parallel to a
face of the cube is limiting within this large, but finite, set of possibilities. In
choosing sequences of color, there may well be reason to follow a diagonal, to tip
a plane, or to find various other ways of selecting subsets of color, as a smoothed
color ramp, from this vast array. It is to these possibilities that we now turn.
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