The 3D axis shows the direction of the Cartesian coordinates in
the 3D window. It consists of 3 legs, a tip at the end of each
leg, and a label specifying X, Y, or Z beyond the tip. The axis
can be drawn using lines, as shown below, or as a solid model
using cylinders and cones. The labels are drawn with lines in
both cases. The 3D Axis property page controls the appearance of
the axis, including its size, line thicknesses, size of the
solid elements, size of the labels, tip details, colors, and
whether or not the tips and/or labels are shown. The axis size
is specified as a percentage of the average extent of the 3D
scale box. In addition to entering the percentage on the 3D Axis
property page, several mouse and key actions change the size.
Moving the mouse with the right button and the a key held down
scales the axis. When the a key is held, the zoom toolbar
buttons and the numeric keypad + and - affect the axis size
(instead of the overall image size). When both the Ctrl and a
keys are held down, the numer