Programming Interactivity, 2nd Edition

Chapter 13. Graphics and OpenGL

If you’re interested in displaying visual feedback or gathering input from a screen, learning how to create three-dimensional graphics is an important skill to learn. We see in three dimensions, we experience in three dimensions, and increasingly we expect our graphics to be in three dimensions. It’s not just a matter of attempting to mimic our experience of the world or meet the expectations of what something should look like in a realistic depiction of a scene; it’s also a matter of providing more data in a manner that humans are accustomed to receiving information.

The ability to make accurate and precise 3-D graphics is core to being able to represent objects in the world effectively. There’s a marked difference between making accurate graphics and realistic graphics. Most architectural drawings, diagrams, and visualizations aren’t particularly realistic, but they are very data rich. They behave the way we expect them to behave when we change the view, rotate the object, or change the distance at which we view the object. When you’re creating an interface, this is far more important than accurately replicating a real-world object. Many times, but not all times, creating a usable interface that provides legibility and usability trumps wowing a user the first time they see something.

A lot of, but certainly not all, advanced graphics code in Processing is written in OpenGL. You can do a great deal with the core graphics classes that are provided in ...