-5 5 setxrange -4 6 setyrange 25 setxunit 10 10 12 SetCamPos 0 0 0 SetCamView qplanxy 2 setlinejoin GetCamPos setlightsrc .1 setlinewidth .6 setgray /f { 2 dict begin /z exch def /y exch def /x exch def x y #rpn# (x^2 + y^2)/4 end } def 5.5 [6 18] newgrillecirculaire dup .8 solidaffine {f} solidtransform dup videsolid dup [.3 .5] solidputinouthuecolors drawsolid**