Strange artifacts after ps to pdf translation

I use the following macros to fill polygons :

/d {currentrgbcolor mark} bind def

/f {setrgbcolor newpath moveto

    counttomark 2 idiv {lineto} repeat

    closepath fill cleartomark setrgbcolor} bind def

and they appear in the code like this :

d 759 4827 814 4772 814 4794 762 4830 .965 .271 .094 f

The prints are OK but when I translate the ps into pdf (for example through the native ps to pdf included in MacOS X) I get strange artifacts on each polygon boundary (white lines) :

Using this procedure to disply 3d structures leads to a mess :

Any hint ?