#!/usr/local/bin/gnuplot -persist
# set terminal pngcairo  transparent enhanced font "arial,10" fontscale 1.0 size 600, 400 
# set output 'pm3d_lighting.1.png'
unset border
set style fill   solid 1.00 noborder
set format x "" 
set format y "" 
set format x2 "" 
set format y2 "" 
set format z "" 
set format cb "" 
set format r "" 
set grid nopolar
set grid xtics nomxtics ytics nomytics noztics nomztics nortics nomrtics \
 nox2tics nomx2tics noy2tics nomy2tics nocbtics nomcbtics
set grid layerdefault   lt black linewidth 1.000 dashtype solid,  lt black linewidth 1.000 dashtype solid
unset key
unset parametric
set view 33, 291, 1.2, 1.3
set samples 200, 200
set isosamples 200, 200
set style data lines
set xyplane relative -0.05
unset ztics
set title "pm3d lighting model with specular highlighting" 
set urange [ -20.0000 : 20.0000 ] noreverse nowriteback
set vrange [ -20.0000 : 20.0000 ] noreverse nowriteback
set xrange [ * : * ] noreverse writeback
set x2range [ * : * ] noreverse writeback
set yrange [ * : * ] noreverse writeback
set y2range [ * : * ] noreverse writeback
set zrange [ -0.250000 : 0.500000 ] noreverse nowriteback
set cbrange [ * : * ] noreverse writeback
set rrange [ * : * ] noreverse writeback
set bmargin  0
set tmargin  0
set pm3d implicit at s
set pm3d depthorder 
set pm3d lighting primary 0.5 specular 0.2 spec2 0
set colorbox vertical origin screen 0.9, 0.2 size screen 0.05, 0.6 front  noinvert bdefault
unset colorbox
slice(x,y) = (x**2+y**2 < 10.0) ? 1.0 : (x**2+y**2 > 300.0) ? NaN : sin(abs(atan2(x,y)))
sinc2(x,y) = sin(sqrt(x**2+y**2))/sqrt(x**2+y**2)
flatten(x,y) = sqrt(x**2+y**2)/5.
F(x,y) =  sinc2(x,y) * slice(x,y) * flatten(x,y)
NO_ANIMATION = 1
## Last datafile plotted: "++"
splot '++' using 1:2:(F($1,$2)):(0xAAEEEE) nosurface lc rgb variable