Cartesian Coordinate Systems - 3D Math Primer for Graphics and Game Development - page 19

regardless of convention, as well. 4 However, in some cases there are some
slight, but critical, differences in application dealing with left-handed versus
right-handed coordinate spaces. When those differences arise, we will point
them out.
We use a left-handed coordinate system in this topic. The +x, +y,
and +z directions point right, up, and forward, respectively, as shown in
Figure 1.15. In situations where “right” and “forward” are not appropriate
terms (for example, when we discuss the world coordinate space), we assign
+x to “east” and +z to “north.”

Figure 1.15
The left-handed coordinate system
conventions used in this topic

1.4 Odds and Ends

In this topic, we spend a lot of time focusing on some crucial material that
is often relegated to a terse presentation tucked away in an appendix in
the topics that consider this material a prerequisite. We, too, must assume
a nonzero level of mathematical knowledge from the reader, or else every
book would get no further than a review of first principles, and so we also
have our terse presentation of some prerequisites. In this section we present
a few bits of mathematical knowledge with which most readers are probably
familiar, but might need a quick refresher.

4 This is due to a fascinating and surprising symmetry in nature. You might say that
nature doesn't know if we are using left- or right-handed coordinates. There's a really
interesting discussion in The Feynman Lectures on Physics about how it is impossible
without very advanced physics to describe the concepts of “left” or “right” to someone
without referencing some object you both have seen.