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CHAPTER TWENTY-THREE

Pixels & Polygons

The Stuff of Light-Beings

ROGER ALTIZER, JR.



Graphics pioneer Jim Blinn once began one of his classes on computer graphics by forcefully tapping a piece of chalk against a blackboard, pointing at the newly made dot and declaring it to be a pixel, stating that a pixel was just a dot (Blinn, 2005). He went on to draw on an Indian folk tale, arguing that just as a number of blind people might touch an elephant (not being told it is an elephant) and each describe it differently—as a tree (having touched the leg), a wall (the side), a rope (the tail), a snake (the trunk), or a spear (the tusk)—a pixel can be many things, described many ways. For instance, to those interested in an avatar’s display quality, pixel density contributes to a display’s resolution; to those interested in how pixels contribute to perceptually real avatar bodies, a pixel might convey a color sample, or one best-fit combination of cyan/magenta/yellow/black as sampling of a theoretically perfect image; to those interested in using avatars as tools to engage a game’s challenges, pixels might be the effectively transparent “DNA” of how that system is displayed. But just as an elephant is not actually a tree, wall, rope, snake, or spear, a pixel—and its three-dimensional (3D) counterpart, the polygon—is not a collection of abstractions. A pixel’s meaning depends on how...