sample of making 3D animated-GIF file

anm_main.gp

set size ratio 0.2
set samples 1000
set isosamples 8

set xrange [0:7]
set yrange [0:7]
set zrange [0:1]
set nokey
#set parametric
set grid

set xlabel "vertical"
set ylabel "horizontal"
set zlabel "PWM\n(ratio)"

DISPLAY_OFFSET		= 0
SIZE				= 0.3
CYCLE				= (1 * 10)
speed				= 3.0

set view 45, 100, 1.0, 1.0

set terminal gif animate optimize size 640, 480
set output "anm.gif"
set tics font 'Times,9'

load "hat.gp"
n = 0

hat.gp

if (exist("n")==0 || n<0) n=0 #変数の初期化

func( x, y, n )	= cos( ( (((x - DISPLAY_OFFSET) * SIZE) ** 2) + (((y - DISPLAY_OFFSET) * SIZE) ** 2) ) ** 0.5 - n * 0.05 * pi ) ** 4

splot [0:7][0:7][0:1] func( x, y, n )

if (n<100) ; n=n+1; reread

clone this repo and execute next command : gnuplot nam_main.gp
it will generate an animated gif file "anm.gif".