Objects can be specified with convenient defaults:
cylinder() is equivalent to cylinder(pos=(0,0,0), axis=(1,0,0), radius=1)
arrow() is equivalent to arrow(pos=(0,0,0), axis=(1,0,0), radius=1)
cone() is equivalent to cone(pos=(0,0,0), axis=(1,0,0), radius=1)
pyramid() is equivalent to pyramid(pos=(0,0,0), size=(1,1,1), axis=(1,0,0))
sphere() is equivalent to sphere(pos=(0,0,0), radius=1 )
ring() is equivalent to ring(pos=(0,0,0), axis=(1,0,0), radius=1)
box() is equivalent to box(pos=(0,0,0), size=(1,1,1))
curve() establishes an "empty" curve to which points can be appended
convex() establishes an "empty" object to which points can be appended
frame() establishes a frame with pos=(0,0,0) and axis=(1,0,0)
