Ah yes, 3D. The wit and wonder, the pitfalls and pratfalls, the might and the magic of computer generated 3D. In my last article I went over some of the basics of 3D polygon and spline modeling, and discussed how objects interact with each other in 3D space. Now it's time to cover the rendering process in more depth - the process which causes 3D to spring to life and brings your computer generated scenes together.
So be it, Jedi.
Since last we spoke, I had the pleasure of returning to my beloved Star Wars universe several times; indeed, my pals and I were the first in line on the opening night of Star Wars Episode 1: The Phantom Menace. The film features over 2000 special effects shots, the most of any film in history (four times more than Titanic, in fact). Phantom's computer-generated creatures, buildings, spaceships, and landscapes were seamlessly integrated into real environments using, according to director George Lucas, just about every off-the-shelf software package in existence and a few of Industrial Light and Magic's own proprietary software applications as well. Highlights: Jar Jar Binks takes some getting used to for his silly voice and clumsy antics, but his realistic movements and detailed expressions are a treat for the eyes. Even more amazing is the obese Boss Nass, whose ample jowls and amphibious lips shake and jiggle realistically as he bellows laughter. These and many other creatures are examples of the very best that the world has to offer in character animation, and there is little doubt that the men and women responsible will pick up an Oscar for their efforts next year.
For many artists getting started in 3D, a question quickly arises: how do you make the models look so realistic? I know how to make a banana, but how do I give it its distinctive, mottled yellow skin? I've crafted a fantastic sword, but how do I make its surface gleam? It's time to texturize!
Putting a surface on a model is simple, and it is difficult. It is as easy as it sounds, but it can also be as complicated as the human DNA strain. It all depends on how detailed you wish to get. For example, if I want to make the surface of a sphere look like shiny black plastic, I don't really need to take too many steps. I can create a simple black bitmap (it theoretically only needs to be the size of a pixel, since it will seamlessly tile to cover the whole model) and wrap it around my model, using whatever 3D software I see fit. Then I simply need to make the texture somewhat reflective (since plastic reflects a small portion of light) and give it a high specularity to for a polished and shiny (as opposed to dull) sheen. If I want to make the sphere appear transparent, like a bubble, I can lower the reflectivity and increase the transparency. If I want the sphere to have a mirror image, I can increase the reflectivity to its highest setting. Makes sense, no?
