set border 4095
set bmargin 6
set style fill transparent solid 0.50 border
unset key
unset colorbox
set view 60, 60, 1.1, 0.6
set samples 40, 40
set isosamples 40, 40
set xyplane 0
set pm3d depthorder border linewidth 0.100
set pm3d clip
set pm3d lighting primary 0.5 specular 0.2 spec2 0

set xrange [-1 : 5]
set yrange [-3 : 3]
set zrange [-10 : 10]
set xtics 2 offset 0,-0.5
set ytics 2 offset 0,-0.5
set ztics 5

f(x,y) = x**2 + y**2 * (1 - x)**3

set multiplot layout 1,2 title "new pm3d default is smooth clipping against zrange"
set title "set pm3d clip4in (old default)"
set pm3d clip4in

splot f(x,y) with pm3d fc "cyan"

set title "set pm3d clip (new default)"
set pm3d clip

replot
unset multiplot


Click here for minimal script to generate this plot