Why 3D?
I happened to read co-worker Jeffrey Ventrella's page http://www.ventrella.com/Ideas/YawPitchRoll/yaw_pitch_roll.html and the "Why 3" part reminded me... Since (most) humans are trichromats, we've settled on a 3-dimensional color space: RGB for emissive and CMY for reflective, although in school you learn the approximation "blue, red, yellow" as the "primary colors". Our color monitors use RGB (subpixel, phosphor) triads which roughly correspond to the light frequencies that (most) human eyes are sensitive to. Graphics programming is often an attempt to make sure the right R, G and B values are used for each pixel to approximate reality. We also generate other color spaces (HSL, HSB) when convenient, each with three parameters. This might indicate that colors are inherently 3D, as is space. Of course, it's all just hacks upon hacks. Light can come in any frequency, from (infra)red through (ultra)violet, and is typically a mix of many fre...