Basic Shapes, Continued
Spheres
Spheres are round. The distance from the center of the sphere to any edge of
the sphere is known as the radius. The radii of spheres extend equally in all
directions from the center. A sphere appears round regardless of viewpoint
or perspective. Shading on spheres is soft and gradual with no abrupt planes
creating sharp contrasts. Changing the length of the radii creates ellipses.
Use ellipses to define the depth of spheres.
Figure 3-12 shows the dimensions of a sphere.
Figure 3-12.—Radii.
Figure 3-13 shows how ellipses define the depth of a sphere.
Figure 3-13.—Ellipses
define the depth of a sphere.
Continued on next page
3-13
