The routine returns the name of the center of the given sphere, or polyhedron c.

If c is a stellated polyhedron (i.e., geom3d[IsStellated](c) returns true), center(c); returns the center of the core of the given stellated polyhedron.

if c is a facetted polyhedron (i.e., geom3d[IsFacetted](c); returns true), center(c); returns the center of the case of the given facetted polyhedron.

If the first optional argument cn is given, the name of the center c becomes cn.

Use coordinates or detail for more details on the center.

The command with(geom3d,center) allows the use of the abbreviated form of this command.