Missing 3D graphic inside plot?

Hello, I have made the given code:

u[r_, phi_] := 
0.018778093057411193`*
Sum[BesselJ[n, 1.5*r] Exp[I n phi], {n, -5, 5}] +     Sum[(0.00042221117650360055`*BesselJ[n, 3*r] + 
3.026131439416714`*^-10*BesselY[n, 3*r])*Exp[I n phi], {n, -5, 
5}] + Sum[
5.062485836886407`*^-9*HankelH1[n, r] Exp[I n phi], {n, -5, 5}];
v[x_, y_] = 
     TransformedField["Polar" -> "Cartesian", 
      u[r, phi], {r, phi} -> {x, y}]
    contourPotentialPlot1 = 
      ContourPlot[Re[v[x, y]], {x, -0.3, 0.3}, {y, -0.3, 0.3}, 
       PlotRange -> Automatic, Contours -> 15, Axes -> True, 
       PlotPoints -> 30, PlotRangePadding -> 0, Frame -> False, 
       ColorFunction -> "DarkRainbow"];
    
    potential1 = 
      Plot3D[Re[v[x, y]], {x, -0.3, 0.3}, {y, -0.3, 0.3}, 
       PlotRange -> Automatic, ClippingStyle -> None, 
       MeshFunctions -> {#3 &}, Mesh -> 15, MeshStyle -> Opacity[.5], 
       MeshShading -> {{Opacity[.3], Blue}, {Opacity[.8], Orange}}, 
       Lighting -> "Neutral"];
    
    level = -1.2 10^8; gr = 
     Graphics3D[{Texture[contourPotentialPlot1], EdgeForm[], 
       Polygon[{{-400, -300, level}, {400, -300, level}, {400, 300, 
          level}, {-400, 300, level}}, 
        VertexTextureCoordinates -> {{0, 0}, {1, 0}, {1, 1}, {0, 1}}]}, 
      Lighting -> "Neutral"];
    
    Show[potential1, gr, PlotRange -> All, BoxRatios -> {1, 1, .6}, 
     FaceGrids -> {Back, Left}]

resulting in this:

However, it does not show the 3D element over the contourplot. The 3D element should look like the figure below, however it is missing in the plot. How can I show it?

Thanks

contourPotentialPlot1 looks fine, however gr, is empty. One problem is the x, y, z range of the graphics objects combined in Show. Partial fix

gr = Graphics3D[{Texture[contourPotentialPlot1], 
   Polygon[{{-.3, -.3, -.0}, {.3, -.3, .0}, {.3, .3, .0}, {-.3, .3, .0}}, 
   VertexTextureCoordinates -> {{0, 0}, {1, 0}, {1, 1}, {0, 1}}]},
   Lighting -> "Neutral"];

Show[gr, potential1,
 PlotRange -> All,
 BoxRatios -> {1, 1, .6},
 FaceGrids -> {Back, Left}]

Cool image!

If all you are trying to do is replicate the second image in your question, then

Plot3D[Re[v[x, y]], {x, -0.3, 0.3}, {y, -0.3, 0.3},
 PlotRange -> {{-0.3, 0.3}, {-0.3, 0.3}, {0, .035}},
 ColorFunction -> Hue]

Nice, but do you see the error in the contourplot in the base? It is white inside the flower petals. This is a Mathematica error or something else. Do you have any idea what is wrong here?

There is no error, Plot3D shows clipped areas in grey, ContourPlot shows them in white. You can change PlotRange to reduce the clipping e.g. PlotRange → {-5, 5} but because of the pole there will always be some clipping, PlotRange -> All, is not useful in this case. You can use ClippingStyle to specify specific colors for the clipped areas, Automatic will use the extremes of the ColorFunction

ContourPlot[Re[v[x, y]], {x, -0.3, 0.3}, {y, -0.3, 0.3},
 PlotRange -> Automatic,
 Contours -> 15,
 Axes -> True,
 PlotPoints -> 30,
 PlotRangePadding -> 0,
 Frame -> False,
 ColorFunction -> "DarkRainbow",
 ClippingStyle -> Automatic,
 Exclusions -> None]

or specify any color you want e.g.

ClippingStyle -> {RGBColor["#486276"], RGBColor["#AC4640"]}

Hello thanks for this. It looks good now, the Real component.

However the Imaginary component “moves” the base-contour up. Have a look, what can I do to make this similar to the Real component?

when using this:

    contourPotentialPlot1 = 
      ContourPlot[Im[v[x, y]], {x, -0.3, 0.3}, {y, -0.3, 0.3}, 
       PlotRange -> Automatic, Contours -> 15, Axes -> True, 
       PlotPoints -> 30, PlotRangePadding -> 0, Frame -> False, 
       ColorFunction -> "DarkRainbow",
     ClippingStyle -> Automatic];
potential1 = 
  Plot3D[Im[v[x, y]], {x, -0.3, 0.3}, {y, -0.3, 0.3}, 
   PlotRange -> Automatic, ClippingStyle -> None, 
   MeshFunctions -> {#3 &}, Mesh -> 15, MeshStyle -> Opacity[.5], 
   MeshShading -> {{Opacity[.3], Blue}, {Opacity[.8], Orange}}, 
   Lighting -> "Neutral" ];
evel = -1.2 10^8; gr = Graphics3D[{Texture[contourPotentialPlot1], 
   Polygon[{{-.3, -.3, -.0}, {.3, -.3, .0}, {.3, .3, .0}, {-.3, .3, .0}}, 
   VertexTextureCoordinates -> {{0, 0}, {1, 0}, {1, 1}, {0, 1}}]},
   Lighting -> "Neutral"];

Show[ gr , potential1,
 PlotRange -> Automatic,
 BoxRatios -> {1, 1, .6},
 FaceGrids -> {Back, Left}]