Z-up
You'll find that even among various computer graphics books, they'll choose
different orientations for the axes. Somewhere in my notebooks, I have a crib
sheet that documents which orientation is used in which book and in which 3D
program. It can be seriously confusing if you try to use more than one 3D book
at a time while writing code. The implications of the axes choice defined on
page 3 of the book percolates all the way through to page 375. 🙂