The command surface controls the display of surfaces by `splot`.
Syntax:
set surface unset surface show surface
The surface is drawn with the style specified by with, or else the appropriate style, data or function.
Whenever surface is issued, `splot` will not draw points or lines corresponding to the function or data file points. Contours may still be drawn on the surface, depending on the contour option. `unset surface; set contour base` is useful for displaying contours on the grid base. See also contour.