3.24.52.1 depthorder

By default the quadrangles making up a pm3d solid surface are rendered in the order they are encountered along the surface grid points. This order may be controlled by the options ‘scansautomatic‘|‘scansforward‘|‘scansbackward‘. These scan options are not in general compatible with hidden-surface removal.

Gnuplot does not do true hidden surface removal for solid surfaces, but often it is sufficient to render the component quadrangles in order from furthest to closest. This mode may be selected using the options

      set pm3d depthorder hidden3d

The depthorder option orders the solid quadrangles; the hidden3d option similarly orders the bounding lines (if drawn). Note that the global option hidden3d does not affect pm3d surfaces.