%
/facetteSphereII {
    /Xpoint Rsphere theta cos mul phi cos mul def
    /Ypoint Rsphere theta sin mul phi cos mul def
    /Zpoint Rsphere phi sin mul def
PointsApresTransformations
    3dto2d
     moveto
theta 1 theta increment add {%
    /theta1 exch def
    /Xpoint Rsphere theta1 cos mul phi cos mul def
    /Ypoint Rsphere theta1 sin mul phi cos mul def
    /Zpoint Rsphere phi sin mul def
PointsApresTransformations
    3dto2d
    lineto
    } for
phi 1 phi increment add {
    /phi1 exch def
    /Xpoint Rsphere theta increment add cos mul phi1 cos mul def
    /Ypoint Rsphere theta increment add sin mul phi1 cos mul def
    /Zpoint Rsphere phi1 sin mul def
PointsApresTransformations
    3dto2d
    lineto
    } for
theta increment add -1 theta {%
    /theta1 exch def
    /Xpoint Rsphere theta1 cos mul phi increment add cos mul def
    /Ypoint Rsphere theta1 sin mul phi increment add cos mul def
    /Zpoint Rsphere phi increment add sin mul def
PointsApresTransformations
    3dto2d
    lineto
    } for
phi increment add -1 phi {
    /phi1 exch def
    /Xpoint Rsphere theta cos mul phi1 cos mul def
    /Ypoint Rsphere theta sin mul phi1 cos mul def
    /Zpoint Rsphere phi1 sin mul def
PointsApresTransformations
    3dto2d
    lineto
        } for 
} def
%
/MaillageSphereII {
/ThetaStart 0 def
departPhi increment 90 increment sub {%
    /phi exch def
ThetaStart increment 360 ThetaStart add increment sub {%
    /theta exch def
% Centre de la facette
    /Xpoint Rsphere theta increment 2 div add cos mul phi increment 2 div add cos mul def
    /Ypoint Rsphere theta increment 2 div add sin mul phi increment 2 div add cos mul def
    /Zpoint Rsphere phi increment 2 div add sin mul def
PointsApresTransformations
    /zCentreFacette ED
    /yCentreFacette ED
    /xCentreFacette ED
% normale à la facette
    /nXfacette xCentreFacette CX sub def
    /nYfacette yCentreFacette CY sub def
    /nZfacette zCentreFacette CZ sub def
% rayon vers point de vue
    /RXvue XpointVue xCentreFacette sub def
    /RYvue YpointVue yCentreFacette sub def
    /RZvue ZpointVue zCentreFacette sub def
% test de visibilité
    /PSfacette RXvue nXfacette mul
    RYvue nYfacette mul add
    RZvue nZfacette mul add def
% norme normale à la facette : rayon de la sphère
% /NormeN {nXfacette dup mul
%          nYfacette dup mul
%          nZfacette dup mul
%          add add sqrt} def
% vecteur centre de la facette vers la source de lumière
/VxLight xLight xCentreFacette sub def
/VyLight yLight yCentreFacette sub def
/VzLight zLight zCentreFacette sub def
% norme
/normeL VxLight dup mul
         VyLight dup mul
         VzLight dup mul
         add add sqrt def
% produit scalaire
/PSLight VxLight nXfacette mul
          VyLight nYfacette mul add
          VzLight nZfacette mul add def
/CosCouleur PSLight normeL Rsphere mul div def
condition {
gsave
newpath
H_S CosCouleur sethsbcolor
facetteSphereII 
closepath
fill
grestore
facetteSphereII
} if
} for
/ThetaStart ThetaStart sepTheta add def
} for
} def