Processing: Creative Coding and Computational Art

need to be stored in memory, and the computer needs to sequentially plot each of the
vertices, too may vertices can become a performance drain on the computer and even
potentially yield worse performance than with raster graphics.
Vector graphics are also resolution independent—one of their best attributes. You are able
to scale vector shapes up or down without any loss in quality. It is just as easy for the computer
to calculate 1000 as 9999, so size is essentially irrelevant with regard to vector graphics.
Additionally, you can edit vector graphics by manipulating their vertices individually—so
they may be deformed in real time, leading to possibilities such as character animation or
shape morphing. One of the reasons a program like Flash became so popular was because
of its strength as a vector-based animation program, which allowed it to effectively overcome
the bandwidth issues associated with the Web, especially back in the days when we
all had slow dial-up modems.
Animation
COMPUTER GRAPHICS, THE FUN, EASY WAY
Animation is really just an extension of static imaging, and everything covered thus far in
this chapter applies to animation. In the simplest sense, animation is a series of still images
displayed sequentially. If the rate of change between images, commonly called the frame
rate, is fast enough, our brains can’t detect the transitions, and you see fluid motion. This
effect is referred to as persistence of vision. In actuality, we perceive the physical world in
much the same way. Light enters our cornea, moves through the pupil and lens, and eventually
reaches the retina. The retina is the light-sensing part of the eye, containing photosensitive
structures called rods and cones. The rods detect low light, while the cones detect
color and detail. The received light is transformed, through a chemical process, into electrical
impulses, which then pass through the optic nerve into the brain to form vision. Thus,
our vision is not static, but—similar to animation—a perpetual sequence of dynamic 2D
data. When I taught painting, I tried to encourage my students to see two-dimensionally, to
record the actual visual data the eye was seeing, not the interpreted image the brain was
forming. I argued that if you wanted other viewers to read 3D space in the painting, you
needed to record the actual perceptual 2D cues that the eyes were seeing, which would
then naturally lead to the perception of 3D space in the viewer’s brain. Our binocular
vision (two eyes) and our brain provide the illusion that we see three-dimensionally and
that the visual field is constant. One simple way to prove the brain’s giant cover-up of the
true visual chaos surrounding us is to detect the eye’s blind spot. At the back of each of
our eyes, where the optic nerve exits the retina, is a structure called the optic disc. The
optic disc has no rods or cones on it to receive light and thus causes a literal blind spot in
our field of vision—actually a blind spot in each eye. However, each of our clever eyes
compensates for the other eye’s blind spot—blinding us to our own blind spots (ignorance
is bliss). Figure 4-4 provides a little example of how to fool the brain and reveal the holes
in your vision. Close your left eye and stare at the dot on the left in the figure. Don’t look
at the star, but you should be able to see it in your peripheral vision. Slowly move toward
the page and keep looking at the dot. When you get to about a foot away or so, the star
on the right should disappear—that’s your blind spot. For a good article on how vision
works, check out http://science.howstuffworks.com/eye1.htm.
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