# create empty molecule and store molecule id.
set molid [mol new ]

# one prism and a vector on top of it
set gidlist [draw prism {-0.7 -0.5 0.0} {0.7 -0.5 0.0} {0.0 1.0 0.0}]
draw color red
append gidlist " " [draw vector2 {0.0 0.0 0.0} {0.0 0.0 2.0} 1.0 20]
draw color green
set sphere [draw sphere {0.0 0.0 -2.0} radius 2.0 resolution 30]

# construct 10x10 vector grid
set field ""
set aconv [expr 3.14159265358979323846/4.5]
for {set i 0} {$i < 10} {incr i} {
    for {set j 0} {$j < 10} {incr j} {
        lappend field [list [list [expr $i - 4.5] [expr $j - 4.5] -5.0] \
                            [list [expr sin(($i-4.5)*$aconv)] [expr sin(($j-4.5)*$aconv)] 7.5]]
    }
}
draw color yellow
set vlist [draw vecfield $field 0.5 10 0.1]
display resetview
rotate x by -80
rotate y by 5

puts "wait for 2 seconds"
sleep 2

#delete the sphere
draw delete $sphere
display update
puts "sphere deleted. wait for another 2 seconds"
sleep 2

# now delete the compound object with out replacement delete
draw delete $gidlist
puts "prism/vector deleted"

# slowly remove the vecfield. use 'display update' to get the animation effect
foreach i $vlist {
        draw delete $i
        display update
        after 25
}
quit