# Generatrix visible in RevolutionPlot3D with thickness

I am trying to plot an open cone (without the base) with a certain thickness. I have first tried with RevolutionPlot3D as follows:

RevolutionPlot3D[{t, t}, {t, 0, 1}, Mesh -> 100,
MeshStyle -> Transparent, PlotStyle -> {Opacity[0.5]},
PlotTheme -> "ThickSurface", Boxed -> False, Axes -> False,
PlotRange -> {{-1, 1}, {-1, 1}, {0, 2}}]


However, the generatrix is visible for some reasons:

I have then tried with Graphics3D and Cone:

Graphics3D[{Cone[], Thickness[0.1]}, ClipPlanes -> {{0, 0, 1, 1}},
Boxed -> False, Axes -> False]


But changing the thickness doesn't seem to change anything. Is there any hidden function to hide the generatrix in RevolutionPlot3D? I understand though that ideally I should use the function Cone since it is less heavy in memory.

• Removing the option PlotStyle -> {Opacity[0.5]} gets rid of most of the line. Is that sufficient?
Aug 27, 2021 at 19:41
• Thanks for the prompt reply. That would indeed work, but I need a minimum of transparency for some other purpose. Aug 27, 2021 at 20:13

This looks like a bug to me. RevolutionPlot3D treats the surface like it were not isotrop in the x y plane, having an edge along the generatrix.

To circumvent this, we may use RegionPlot3D instead of RevolutionPlot3D:

wall = 0.04;
RegionPlot3D[(z - wall) <=
Sqrt[x^2 + y^2] <= (z + wall), {x, -1 - wall,
1 + wall}, {y, -1 - wall, 1 + wall}, {z, -wall, 1},
PlotPoints -> 100, Mesh -> None, Axes -> True, Boxed -> True,
PlotStyle -> Directive[Opacity[0.5]],
PlotRange -> (1 + wall) {{-1, 1}, {-1, 1}, {0, 1}}]


• Thank you, that works perfectly! Aug 30, 2021 at 21:38