The Add Objects
Sphere tool inserts a Geo Sphere primitive in the Working-Volume
at the location of the 3D Cursor.
A Geo sphere has the properties that it is symmetric when viewed from any position.
Sphere primitives can also be generated with exact dimensions or drawn interactively using the Build > Build Primitives menu.
The Build Primitives Sphere Tab page enables the generation of Spherical models by a specified dimension.
Type in the desired Radius, number of Faces, Smoothing choice (Off creates a faceted sphere when rendered) and Center point, then press the Make button. Note that the Center is the point in the Working-Volume 3D space that the center of the Sphere is placed.
You can also interactively generate a Sphere primitive by dragging out a bounding box in any of the Working-Volume' TOP, FRONT, or SIDE views. The specified Sphere will fill the space of the bounding box. Note that the Auto checkbox must be checked to interactively draw primitives.