Learning Processing, 2nd Edition

14

Translation and Rotation (in 3D!)

What is the Matrix?

—Neo

In this chapter:

– 2D and 3D translation

– Using P3D and P2D renderers

– Vertex shapes

– 2D and 3D rotation

– Saving and restoring the transformation state: pushMatrix() and popMatrix()

14-1 The z-axis

As you have seen throughout this book, pixels in a two-dimensional window are described using Cartesian coordinates: an x (horizontal) and a y (vertical) position. This concept dates all the way back to Chapter 1, when I discussed thinking of the screen as a digital piece of graph paper.

In three-dimensional space (such as the actual, real-world space where you’re reading this book), a third axis (commonly referred to as the z-axis) refers to the depth of any given point. In a Processing sketch’s ...