# Copyright © 2009 by David Bremner <bremner@unb.ca>
# Distributed under the same terms as sketch (http://www.frontiernet.net/~eugene.ressler)

def INFINITY 40
def LONGS 40
    
def up [0,1,0]
def forward [0,0,1]

def eye (2,3,4)
def O (0,0,0)

special|\tikzstyle{novert} = [draw=white,double=black]|[lay=under]

def circ {
       sweep {INFINITY, rotate(360/INFINITY,(O),[forward])} (0,1,0)
}


def longcirc {
       sweep {INFINITY, rotate(360/INFINITY,(O),[up])} (0,0,1)
}

put { view((eye),(O),[up]) then scale(4) }{
    sweep[line style=novert]{LONGS, rotate(360/LONGS,(O),[up])} {circ}
}
global {language tikz}