Reality and the world of 3D - Part 04

Reality - Continued 3

Let's continue our discussion of what objects do by switching focus to something more complex, like light. Light can be thought of as an object that has a source. It may be totally invisible in its own right, but it also has the ability to change the color, brightness and other properties of many other objects in its path. Thus we have defined that light has a source and a direction. The source of the light may be a chemical reaction or heating element emiting light or any of a myrriad other sources.

“But wait!” you exclaim. “What's this about direction? When I turn on my upright floor lamp in the living room, it lights up the whole room, even though the only opening on the lamp faces straight up.”

You're right, this is exactly what happens, but keep in mind that we see light on how it hits our eyes, so if your lamp faces up and the room lights up, what we're seeing is light reflecting off of the various objects in the room, including the metalic lamp shade that's open at the top. And depending on the design of your lamp, we may even see the actual light source, but if there were no objects in the room, the light wouldn't actually do anything other than be a big glowing blob hanging in mid-air. In other words, we see light as a reflection of photons from surfaces of other objects.

What other properties does light have? Well, it has color, it cannot pass through solid objects, thus casting shadows(which themselves have properties), and it has intensity. All these properties of light define not how light itself looks but rather, how objects off which it reflects look. Which brings up another point about two additional properties of objects: reflectivity and highlights.

Please stay tuned...