DOMPoint: z property
Note: This feature is available in Web Workers.
The DOMPoint interface's
z property specifies the depth coordinate of a point in
space.
Unless transforms have changed the orientation, a z of 0 is
the plane of the screen, with positive values extending outward toward the user from the
screen, and negative values receding into the distance behind the screen.
Value
A double-precision floating-point value indicating the z coordinate's value
for the point. This value is unrestricted, meaning that it is allowed
to be infinite or invalid (that is, its value may be NaN or
±Infinity).