Here is an example of how to make a sphere:
This produces a sphere centered at location (1,2,1) with radius = 0.5, with the current foreground color.
The sphere object has attributes pos, x, y, z, axis, length, color, red, gree , blue, and up like those for cylinders. As with cylinders, up has a subtle effect on the 3D appearance of a sphere. The axis attribute only affects the orientation of the sphere and has a subtle effect on appearance; the magnitude of the axis attribute is irrelevant. Additional sphere attributes:
radius Radius of the sphere
Note that the pos attribute for cylinder, arrow, and cone corresponds to one end of the object, whereas for a sphere it corresponds to the center of the object.
Originally there was a label attribute for the sphere object, but this has been superceded by the label object.