# Improving a region plot

I have two surfaces which I plot them using

p0 = Plot3D[{2  x Cos[y] + 2 x Sinh[y], -2  x Cos[y] -
2 x Sinh[y]}, {x, -1, 1}, {y, 0, 7}, ClippingStyle -> None,
PlotStyle -> {Directive[Green, Opacity[0.5]],
Directive[Green, Opacity[0.5]]}, PlotPoints -> 25
, Lighting -> {{"Ambient", White}},
PlotRange -> {{-0.5, 0.5}, {0, 7}, {-1.0, 1.0}}]


To fill the region between these two surfaces, I use

p1 = RegionPlot3D[{2  x Cos[y] + 2 x Sinh[y] + v < 0 ,
2  x Cos[y] + 2 x Sinh[y] - v < 0}, {x, 0, 1}, {y, 0, 7}, {v, -1,
1},  PlotStyle -> {Directive[Yellow, Opacity[1.25]],
Directive[Yellow, Opacity[1.25]]}, PlotPoints -> 25,
Lighting -> {{"Ambient", White}}, AspectRatio -> 1, Mesh -> None]
p2 = RegionPlot3D[{2  x Cos[y] + 2 x Sinh[y] - v > 0 ,
2  x Cos[y] + 2 x Sinh[y] + v > 0}, {x, -1, 0}, {y, 0, 7}, {v, -1,
1},  PlotStyle -> {Directive[Yellow, Opacity[1.25]],
Directive[Yellow, Opacity[1.25]]}, PlotPoints -> 25,
Lighting -> {{"Ambient", White}}, AspectRatio -> 1, Mesh -> None]


Finally, I plot all of them together using

Show[p0, p1, p2, PlotRange -> {{-0.5, 0.5}, {0, 7}, {-1.0, 1.0}},
Mesh -> None]


The outcome looks like While this script fulfills my initial inquiry, I am not fully happy with the plane at x=0, which is there because of having separated regions p1,p2. Do you have a suggestion on improving this figure and removing the line at x=0?

I found another way to do this which only use Plot3D, the keypoint is using Filling.

Clear[g, plot1, plot2];
g[x_, y_] = 2 x Cos[y] + 2 x Sinh[y];
plot1 = Plot3D[{g[x, y], -g[x, y]}, {x, -1, 1}, {y, 0, 7},
PlotRange -> {{-1, 1}, {0, 7}, {0, 1}}, PlotStyle -> Green,
ClippingStyle -> None, Filling -> Top, FillingStyle -> Yellow,
PlotPoints -> 100, MaxRecursion -> 4, MeshFunctions -> {#3 &},
Lighting -> {{"Ambient", White}}];
plot2 = Plot3D[{g[x, y], -g[x, y]}, {x, -1, 1}, {y, 0, 7},
PlotRange -> {{-1, 1}, {0, 7}, {-1, 0}}, PlotStyle -> Green,
ClippingStyle -> None, Filling -> Bottom, FillingStyle -> Yellow,
PlotPoints -> 100, MaxRecursion -> 4, MeshFunctions -> {#3 &},
Lighting -> {{"Ambient", White}}];
Show[plot1, plot2, PlotRange -> All]


Maybe this.

Clear[g];
g[x_, y_] = 2 x Cos[y] + 2 x Sinh[y];
p0 = Plot3D[{g[x, y], -g[x, y]}, {x, -1, 1}, {y, 0, 7},
ClippingStyle -> None,
PlotStyle -> {Directive[Green, Opacity[0.5]],
Directive[Green, Opacity[0.5]]}, PlotPoints -> 25,
Lighting -> {{"Ambient", White}},
PlotRange -> {{-0.5, 0.5}, {0, 7}, {-1.0, 1.0}}];
plot = RegionPlot3D[{-v <= g[x, y] <= v , v <= g[x, y] <= -v}, {x, -1,
1}, {y, 0, 7}, {v, -1, 1}, Mesh -> None,
PlotStyle -> Directive[Yellow, Opacity[1]],
Lighting -> {{"Ambient", White}}];
Show[p0, plot]