Spheres

The sphere command creates spheres.

sphere takes two arguments: P,R, either two points or a point and a real number.
sphere(P,R) returns:
- a sphere with diameter PR, if R is a point.
- a sphere with center P and radius R, if R is a number.

sphere([-2,0,0],[2,0,0])

sphere([0,0,0],2)