set style line 100 lw 0.1 lc rgb "#cccc00"
set pm3d depthorder hidden3d ls 100
set palette rgb 7,0,0
unset colorbox
set parametric
set ticslevel 0
set xtics 0.5
set ytics 0.5
set view 70,170
set isosamples 36,24
set urange[0:pi] 
set vrange[-pi:pi]
splot sin(u)*cos(v),sin(u)*sin(v),cos(u)+sin(u) w pm3d
pause 3
set term pngcairo transparent fontscale 0.7 size 360,360
set out "heart.png"
replot