#
# Illustrate use of secondary spotlight in pm3d lighting model
#
unset key
unset colorbox
unset tics
unset border
set parametric
set dummy u, v
set view  equal xyz
set view 90., 0., 1.6
set samples 95
set isosamples 95
set xyplane at 0
set pm3d depthorder 
set pm3d lighting primary 0.5 specular 0.2 spec2 0.5
set pm3d spotlight rgb 0xff0044 rot_x 35 rot_z 0 Phong 10.0

# Bind hot keys to move spotlight origin phi/psi
spot_x = 35
spot_z = 0
bind all 'x' "spot_x = spot_x+5.; set pm3d spotlight rot_x spot_x; replot"
bind all 'X' "spot_x = spot_x-5.; set pm3d spotlight rot_x spot_x; replot"
bind all 'Y' "spot_z = spot_z-5.; set pm3d spotlight rot_z spot_z; replot"
bind all 'y' "spot_z = spot_z+5.; set pm3d spotlight rot_z spot_z; replot"

set title "In interactive terminals,\nHot keys x/X and y/Y move red spotlight"
splot cos(u)*cos(v),cos(u)*sin(v),sin(u) with pm3d fc "gray"


Click here for minimal script to generate this plot