(See e.g. www.povray.org) .o::.. ... ::8o 88:::::. oO8:::::. o:. ..::::::o .:::::::Oo .:8o ::88 88::: ':: 88:::''8:: 8:: o:: ::8 :::8 ::o' '::88 ::88 .::88 88::: 8: 88:: 8:: 8o:: 8:: ::8...::oO ::8 ::88 ::88 ::88 88::: O: 88:: 8:: 8:: 8:' ::::oo::o ::8 ::88 ::o8 .::88 88::::::: 88:: 8:: 8:: o::..::8 ::8 :::::::::88 '::o8::88 88:::::' 88:: 8:: ..:::oo:::oo:::.. ::8 ::8 '::88 ':::88 88::: 88:: 8:.::oo:::::::::.:.oo:.:8 ::8 ::88 ::88 88::: 88:: .:oo::::::::::.:...:.oo:. ::8 ::88 ::88 88::: 88:: .:o:o::::::::::::.. ..:.:oo:.'8 ::88 ::88 88::: O8::..:oo:::::::::::::.:...:.::::oo. ':8O ::8O 88::' 'O:::oo::::::::::::::::.:.::::::oo:: ::O% ::::::::::::::::::::::::::::::::: o.o.o.o.o.o.o.o.o.88oooooooooooooooooooooooooooo8888.o.o.o.o.o.o.o.o.o. ..ooo..:.:.oo888''..oo..oo..oo..oo|..oo..oo..oo..oo ``oo..oo..oo..oo..o ==8888888888888888'...ooo...ooo...|ooo...ooo...ooo'8888oooo88888ooooo88 ................oO8:oo..oo....oooo|....oooo..oo..::8888888888888888888- 8888888888888O'' :..oooo.......|ooooooo....ooooooooooo. ''''''''''O:.........:...ooooooooo|.........ooo'8888888888:............ .oo8888888888888/''.....ooooo|.....ooooo'8`o `O8888888 .oo8888888888888888/ '........|oooooooo'88888o `O888 o88888888888888888/' '''...|OOOO''888888888O. `8 '''''''''''''''''oooooooooooooooooo'''''''''''''''''''ooooooooooooooooo ./8888888888888888888 `\888888888888888 ./88JJJ8W888W8888888888 `\8888888888888 ./888888J8W8W8W8888888888 `\88888888888 /888888J8J8W8W8W8888888888 \8888888888 ./8888888JJJ88W8W88888888888 `\88888888 /8888888888888888888888888888 `\888888 Jan Walzer