polygons

2D plots:

     plot DATA {using 1:2} with polygons

plot with polygons is treated as plot with filledcurves closed except that each polygon's border is rendered as a closed curve even if its first and last points are not the same. The border line type is taken from the fill style. The input data file may contain multiple polygons separated by single blank lines. Each polygon can be assigned a separate fill color by providing a third using specifier and the keywords fc variable (value is interpreted as a linetype) or fc rgb variable (value is interpreted as a 24-bit RGB color). Only the color value from the first vertex of the polygon is used.

3D plots:

     splot DATA {using x:y:z} with polygons
           {fillstyle <fillstyle spec>}
           {fillcolor <colorspec>}

splot with polygons uses pm3d to render individual triangles, quadrangles, and larger polygons in 3D. These may be facets of a 3D surface or isolated shapes. The code assumes that the vertices lie in a plane. Vertices defining individual polygons are read from successive records of the input file. A blank line separates one polygon from the next.

The fill style and color may be specified in the splot command, otherwise the global fillstyle from set style fill is used. Due to limitations in the pm3d code, a single border line style from set pm3d border is applied to all 3D polygons. This restriction may be removed in a later gnuplot version, which will impose a distinction between the linecolor and fillcolor properties.

Each polygon may be assigned a separate fill color by providing a fourth using specifier and the keywords fc variable (value is interpreted as a linetype) or fc rgb variable (value is interpreted as a 24-bit RGB color). Only the color value from the first vertex of the polygon is used.

pm3d sort order and lighting are applied to the faces. It is probably always desirable to use set pm3d depthorder.

     set xyplane at 0
     set view equal xyz
     unset border
     unset tics
     set pm3d depth
     set pm3d border lc "black" lw 1.5
     splot 'icosahedron.dat' with polygons \
           fs transparent solid 0.8 fc bgnd