I am looking for an easy way to force this plot to label the $y$ axis with numbers below the axis automatically in the given view point. Now the label switches to the bottom when the view point reaches a certain angle, but I would like to have the labeling always below the $y$-axis.
The existing answers could not help so far (mostly for 2D only). Using the Epilog function changes the font and the angle as far as I was able to test it.
Furthermore, I would like to mark the ticks at: {{0, -20, 0}, {0, -10, 0}, {0, 0, 0}, {"r/2", 0, 0}, {"r", 0, 0}} with a little black cross, but cannot work it out.
Are there ways to solve these problems? Many thanks in advance.
circle3D[centre_: {0, 0, 0}, radius_: 20, normal_: {0, 0, 1}, angle_: {0, 2 Pi}] :=Composition[Line, Map[RotationTransform[{{0, 0, 1}, normal}, centre], #] &, Map[Append[#, Last@centre] &, #] &, Append[DeleteDuplicates[Most@#], Last@#] &, Level[#, {-2}] &, MeshPrimitives[#, 1] &, DiscretizeRegion, If][ First@Differences@angle >= 2 Pi, Circle[Most@centre, radius], Circle[Most@centre, radius, angle]] cGr = Graphics3D[{Thick, Dashed, circle3D[{0, 0, 0}, 20]}]; c1 = Graphics3D[{Thick, Dashed, circle3D[{0, 0, 20}, 20]}]; Show[c1,Ticks -> {Automatic,Table[i, {i, -20, 20, 10}], Automatic},AxesStyle -> Thickness[0.004], Boxed -> False, Axes -> True,AxesOrigin -> {0, 0, 0},Boxed -> False,PlotRange -> {{-20, 20}, {-20, 20}, {0, 30}}, ImagePadding -> {{0, 40}, {40, 70}}, ViewPoint -> {0.8 Pi, -1.5 Pi, 0.20 Pi}] 