In WPF 3D programming, you find that you use the Vector3D structure almost as much as Point3D. I'll discuss some basic concepts of vectors in this chapter, but I'll be introducing progressively more and more vector-related mathematics throughout this book.
A vector encapsulates a magnitude and a direction, and is generally pictured in 3D space like so:
Figure 1-13. AxesWithVector.xaml
The magnitude of the vector is symbolized by its length; the direction is symbolized by the arrow. Showing a vector occupying a specific location in 3D space is somewhat deceptive, however. Vectors have no physical location, much like a weight ...