The previous code snippets have touched on how to move objects and views around in 3-D in a Processing application, but these all merit a closer examination.

There are two coordinate systems in Processing to consider: the coordinates of the world and the coordinates of the screen. The difference is the location of the 0,0,0 point. Although a model may have its 0,0,0 point in one location, because of rotations and transformations applied to the model, it will appear in an entirely different location on the screen, as in Figure 13-8.

Figure 13-8. The model coordinate system and the screen coordinate system may not be the same values

Imagine that you have a cube you’ve drawn as shown in the code snippet below: