set pm3d explicit
set palette rgb 9,9,2
unset colorbox 
set hidden3d
set parametric
set size square
set samples 36
set isosamples 20,36
set ticslevel 0
set view 70,170,1.1,1
set urange [0:pi]
set vrange [0:2* pi]
set term png transparent xffffff
set out "graph_ex1.png"
set multiplot
splot sin(u)*cos(v),sin(u)*sin(v),cos(u) w pm3d
splot sin(u)*cos(v),sin(u)*sin(v),cos(u) lt 3
unset multiplot
!convert -geometry 30% -colors 512 graph_ex1.png graph_ex1s.png