a := 1
a.minimum := -2
a.maximum := 2
b := 1
b.minimum := -2
b.maximum := 2
c := 1
c.minimum := -2
c.maximum := 2
d := 1
d.minimum := -2
d.maximum := 2
graph3d.box := true
graph3d.mesh := true
graph3d.view := top
graph3d.perspective := false
graph3d.resolution := 31
graph3d.highlight := 0
graph3d.shading := 0
graph3d.contrast := 1/2
graph3d.transparency := 0
graph3d.color := byheight
graph3d.background := white
graph3d.minimumx := -3
graph3d.maximumx := 3
graph3d.minimumy := -3
graph3d.maximumy := 3
graph3d.minimumz := -0.2
graph3d.maximumz := 0.2
graph3d((
         y<d*x                    ;under diagonal
       & y<a*sin(b*x+c)           ;under sine wave
       & x^2+y^2<6*|sin(time/3)|  ;inside pulsing disk
       & z>-0.1, y>d*x            ;between a thin
       & y>a*sin(b*x+c)           ;cylinder ?
       & x^2+y^2>6*|sin(time/3)|  ;use arrow keys !
       & z>0.1                    ;influences color 
       , y=d*x                    ;diagonal line 
       , y=a*sin(b*x+c)           ;sine-curve
       , x^2+y^2=6*|sin(time/3)|  ;pulsating circle
       , x=0                      ;y-axis
       , y=0                      ;x-axis
))